# Smart Fortwo EV..... High power version!!



## Yabert (Feb 7, 2010)

Hi all

Many of you have view my motorcycle project http://www.diyelectriccar.com/forums/showthread.php/suzuki-drz-sm-2005-electric-48239.html

But it was only a test for introduce the mecanical guy in mine to electric power...
So now it's time to the real project: An electric car fun to drive!

My first idea, last year, was to convert my old mercedes 190 for have a high power RWD fun to drive car (just a step under the Cro Driver BMW...). But I performed some calcul and the cost have no sense for the performance I need. 
So because my budget is a bit limited I decide to reduce all the need in part like less powerfull controller and motor, less quantity of battery and that give:

-Donor car: BUY! Smart fortwo 2005 (real 730 Kg Go-Kart) It have a lot of room under the floor!
-Battery: Headway 10Ah, 48S-8P for 154V and 1000A at 12.5C
-BMS: Mini BMS centralized (3x 16S)
-Controller: BUY! Kelly KDHD 156V 1000A
-Motor: 11" modified forklift motor for good torque
-Gear box: Direct drive with 3.5:1 to 4:1 ratio



And now I have few question for you....

-I find a crown 11" forklift motor (W11AB02). I think it is a bit small! The frame is only 7-7/8" long and it's rate 9.6 Kw at 48v. The battery are rate for 115 Kw, the controller is rate for 180 Kw, so do you think this motor will be capable enough Kw to match with battery and controller? Or I need something much close to a Warp 11?

-I think don't use the original transmission because it's probably not enought strong to pass all the torque and I need a LSD differencial. I'm probably capable to build a fix ratio transfer case with integrated limited slip but I will need 4 kilovac contactor to go in reverse. In the other way I'm probaly capable to integrated some FWD LSD transmission (Honda, Volks, or....) without clutch and set to a fix ratio to have a mecanical reverse. What will be the better choise?

-What kind of charger I can match with mini-bms on 120v outlet (1800w) can give the shorter time of charge (1800w x 0.9 effiency = 1620w / 173v (48x3.6v) = 9A...... 64Ah / 9A = 7.1h of charge...... oh! fucking long)

-What do you think about the project? Good voltage? to low? Other BMS suggestion? Motor? Other concern?


Thanks

Final product: http://www.evalbum.com/4155 
*December 2015*. Many pictures are not shown anymore, so I've create an album here: https://imageshack.com/a/uyz4/1


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## Woodsmith (Jun 5, 2008)

Looks like a fun project.
The motor is similar in size to my 11" for my trike but mine is 80v 12.6kW.

When I bought a mig welder from a closing down factory unit recently, the seller was a disabled trike builder. He showed me a differential unit he says is use in rally cars. LSD, quick change ratios and a reversing lever so that the diffs can be used in either rotation.

Now, annoyingly, I can't remember the manufacturer details but a quick search on disabled trikes brought up this:
http://www.trikeshop.co.uk/disabled_adaptions.htm
At the bottom of the page is a reversing gear adaptor that might be useful for you to put between the motor and transmission.
There will, no doubt be other types available but maybe searching around disability adaptations might be a good start.


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## Yabert (Feb 7, 2010)

Woodsmith said:


> At the bottom of the page is a reversing gear adaptor that might be useful for you to put between the motor and transmission.


Add another component between motor and gearbox isn't the best way to get a simple and efficient design. Also, 11" motor can probably give to much torque for this kind of equipement.

Well there is not a lot of reply.... 

At this moment I have buy the 730Kg Smart Fortwo, the 1000A controller and the 1000A capable Headway battries, so now the most important thing to know is if the 11" Crown motor is capable to puch this set-up to 60 Mph under 6 or 7 second!!!

How much torque is capable this motor at 1000A and for how many RPM it can sustain this torque?


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## dimitri (May 16, 2008)

For what its worth, you can use MiniBMS with any charger, so charger selection is not related to BMS, but based on what available mains circuits you will have for charging, so you don't blow their fuses.

Also, you mix 1000Amp figures in motor side and battery side calculations, but you will never actually pull 1000Amp on the battery side, especially with Kelly controllers, which are well known for their fictional ratings. You didn't mention your planned EV range, which depends on C rate you pull from the pack. More C rates means less time to drive on one charge.

I am not a motor expert, but I know the main challenges of direct drive is limited RPM/power band of DC motor and heat buildup at low RPMs. Its quite difficult to find a single sweet spot in gearing down which allows for enough power at low speed yet be within motor's RPM limit at top speed. Direct drive certainly means much less electrical efficiency, hence more motor/controller heat to deal with.

At high C rates, you may even have to deal with battery cooling, especially the cells inside the pack, where heat is not easily removed. If ignored, middle cells might fail sooner than others if they get hot on regular basis.

I have seen several attempted direct drive conversions and I can't recall one where it didn't suffer from this decision. Either poor acceleration or poor range, or poor top speed, or overheating of power components.


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## Yabert (Feb 7, 2010)

Thanks for the answer.



dimitri said:


> you will never actually pull 1000Amp on the battery side, especially with Kelly controllers.


It's the "new" type of controller from Kelly. Supposed to be more powerfull than the old model....
Maybe it's a bad choise, but now I need to test it! Wish me luck!!




> You didn't mention your planned EV range


I expect to drive between 40 and 50 miles in normal condition.





> I know the main challenges of direct drive is limited RPM/power band of DC motor and heat buildup at low RPMs. Its quite difficult to find a single sweet spot in gearing down which allows for enough power at low speed yet be within motor's RPM limit at top speed.


I try to resolve this problem with the equation: Lightweight car + Overbuild motor and controller + 90 mph top speed = good compromise.

My direct drive motorcycle had great acceleration (0-50 Mph around 5 sec.) but the problem was the limited top speed of 68 Mph. I think this problem will be resolve with the relatively high voltage (154v) for the Smart compared to the 84v of my motorcycle.

I have calculed the weight of the Smart (with me onboard) is 3.8 time more than the weight of my motorcycle. So to have similar acceleration I need roughly 3.8 times the torque of the 6.7" D&D es-15-6 motor and that give 305 lbs-pi. The short 11" Crown motor can give this torque?




> At high C rates, you may even have to deal with battery cooling, especially the cells inside the pack, where heat is not easily removed. If ignored, middle cells might fail sooner than others if they get hot on regular basis


I know! I need to design a good managed battery pack. I work on this right now!


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## Woodsmith (Jun 5, 2008)

Yabert said:


> Add another component between motor and gearbox isn't the best way to get a simple and efficient design. Also, 11" motor can probably give to much torque for this kind of equipement.


Granted, that unit might not be right.

I think the company I met, when I bought my MIG, is a UK branch of this company:
http://www.mobilityconquest.com/wheelchair-motorcycles-specs.php
The body mouldings, donor bike and specifications all seem to be the same.
If I am right they use, I'm told, a rally car spec limited slip diff with quick change gears and a mecanical reverse within the diff.
It might be a strong and easy way to set up a direct drive where you can have a selectable reverse and adjust the ratio to suit the motor if you need to.


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## Duncan (Dec 8, 2008)

Hi Yabert

I have been thinking about the reverse gear issue - for a lightweight 2 seater

(1) -No reverse just push it back
(2) - Use the reversing contactor I got from an old forklift - should never be actuated under load
(3) - use two double Alderson connectors to reverse the field coils
unplug the green ones plug in the red ones!
(4) - Lotus 7 type cars with motorbike engines use a starter motor to drive the car backwards


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## MalcolmB (Jun 10, 2008)

Hi Yabert

It looks like we're in a similar position: both planning to convert lightweight cars using motors we know very little about, and wanting to achieve decent performance from a single-ratio transmission. I can't provide the information you really need, which is a torque curve and maximum speed for your motor, though I did find this: http://img214.imageshack.us/i/pdfeb7.jpg/

Your suggested gear ratio of 3.5-4.0 sounds about right to me. What motor rpm would this require to get you to 90 mph?

I've found it useful just plugging different values into this calculator: http://www.diyelectriccar.com/forum...-charts-ev-performance-spreadsheet-41565.html (Thanks to maxvtol!)

Working with a maximum motor torque of 150 ft lbs I found that the optimum gear ratio for decent acceleration and a top speed of 80 mph is around 4.5:1. (For a 1500 lb vehicle with rpm limit of 6000 for my 7" motors).

I know a lot of people dislike the idea of fixed gear drive, and I agree that it's a big compromise. For example I also found when playing with the calculator that by using a three-speed transmission with optimised ratios I could get my 0-60 time down from just over 8 seconds to around 5 seconds and increase top speed to 90 mph, though this didn't include shift times. Even so, the advantages of using a single ratio are sufficient to make me think it worthwhile, especially in a lightweight vehicle with very limited space. One of the things I really like about my bike, which is also fixed gear, is just the simplicity of it and the way the power winds on so smoothly. It doesn't feel incredibly fast, but sails away from the lights leaving most other traffic behind. It's surprising how much time is lost with gear changes.

I'm also trying to decide how to get reverse. Costs are about the same for a good set of reversing contactors or a starter motor for reverse drive, but the reversing contactors are lighter and easier to install.

Your plans look good to me, and now you've got the controller there's no point in worrying about voltage any more. That's one less decision to make!


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## dimitri (May 16, 2008)

Yabert said:


> I expect to drive between 40 and 50 miles in normal condition.


Lets say you want to drive those 40-50 miles at average speeds of 40-50 mph, just to make a simple point. This means your average battery current should be under 1C, since you expect to be driving for an hour and you don't want to reach 100% DOD. For simplicity sake lets assume that acceleration bursts and periods of coasting will cancel each other out, so average cruising current has to be under 1C.

Since you plan a battery of 80AH, that means your cruising current should be under 80Amps.

In my experience, typical acceleration current is 3-5 times more than cruising current, which puts you in the 300-400Amp range for heavy acceleration. Good news here is that you don't exceed 5C, so no need to worry about pack cooling.

I would recommend to design your battery pack such that you can add more cells in parallel to existing 48 groups later on, if/when you realize you need more capacity to get your range, so you can get from 48S8P to say 10P or 12P without having to redo a lot of work.

Of course none of this math answers the question, can your motor provide both acceleration and top speed with a single gear ratio.


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## Duncan (Dec 8, 2008)

Hi Yabert
On the direct drive v gearbox
You may be in the same situation I was in - 
I intended to use an old Ford gearbox - I even bought one!
Then I did some calculations and decided that with a 750Kg vehicle I would be able to break traction in top gear 
top gear was 1:1 and top speed 80 mph 
(at 5,000 rpm - I hope my forklift motor doesn't blow up) 
Without a gearbox the motor fits in what would have been the transmission tunnel - leaving the "engine bay" for batteries

If you can break traction then a gear box is unnecessary!

Calcs

Motor torque x axle (diff) ratio = wheel torque
Wheel torque / tire radius = Force at tire contact patch

Vehicle weight on the driven end x tire coefficient of friction (0.8 for "inexpensive" road tires (did I mention I am a Scotsman)) = Max force the tires can use


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## lloydn (Dec 8, 2009)

That looks like an interesting equation there Duncan. 

Just wondering where you got it from, and the units you are using, because I can't seem to get it to work with numbers I've been running, and I'd be quite interested in it. 

Just to illustrate, I have an 02-05 Ford Fiesta currently. Weight is about 1045kg. Max Torque from the 1.25 is 110Nm. Wheel radius is 0.292m. 

Motor Torque (Nm)Gear RatioWheel Torque (Nm)Wheel Force (N)11015.2866168257601108.241190731061105.465660120581104.056544615271103.24523571223

Given your equation: 
"Vehicle weight on the driven end x tire coefficient of friction (0.8 for "inexpensive" road tires = Max force the tires can use"

and an estimate of 60% weight on the driven wheels (627kg)

627 * 0.8 = 501.6N

Much lower than the force available in any gear. And Force divided by mass gives acceleration, so that would be 0.48 m/s^2, or a 0-62 of about a minute. Pretty sure my car isn't that slow... So I think it must be a different units thing, please let me know what you're equation is using. 


What I've been using to judge the maximum usable torque is: 

Torque = distance (radius of wheels) x mass (kg) x acceleration (m/s^2)

Then looking at other road cars to see what a reasonable max acceleration is. The maximum seems to be about 0.5g for FWD, and 1g for RWD. 

Using that equation on my Fiesta gives about 1497Nm (about 5 times the force of the previous equation). First gear makes more sense with that result. 


And for Yabert: 

On the Smart, 0.287 radius wheels, 750kg, RWD, gives 2112Nm maximum. I'm not sure the smart is really set up to handle that much though, so just think of it as an absolute maximum. 

In order to achieve 0-50 in 5.2 seconds (0-60 in 6.3) with direct drive, you'd need about 1200Nm of Wheel Torque, or 300Nm of Motor Torque with a 4:1 ratio. That is about 56kW of power. 

If 90mph is the max speed, and 4:1 is the ratio, then 60mph is 3440rpm; so you need a motor that can develop 300Nm or more Torque from 0-3440rpm. That's 0-60 in 6.3s ish. 

If you did get the torque of a warp 11 at 1000 Amps (434Nm, according to evsource), you'd get better than Tesla Roadster level acceleration. 


I don't know much about motors, so hope for one of the more knowledgeable guys to come along, but this is my best guess with what you have. 

The 9.6kW at 48v is 200A continuous, similar to the warp motors. The commutator section looks quite big, so should overload quite well, and will probably take the 1000Amps if they Kelly really supplies it, for a short time. I don't know how much torque per amp you will get though, if there is a torque rating on the motor, please let us know. 

5000-6000rpm for that size motor would seem like a reasonable limit. If the motor has an rpm rating, it would help to know that too. 

My concern would be that at 150v it might be spinning too fast, or if it is spinning at a good speed, would not be producing the torque that you need.


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## Yabert (Feb 7, 2010)

MalcolmB said:


> What motor rpm would this require to get you to 90 mph?


My wheel have a diameter of 22.58" so at 90mph with 3.7:1 ratio that give 4955 motor rpm.

Thanks a lot for the link for the performance calculator.
But I see one strange thing when I played with the prameter of this calculator. Why at 125v (48s sag to 2.6v) the Warp 9 give his max torque from 0 to 3750 rpm and the Warp 11 can give his max torque only from 0 to 2750 rpm. When I played with gear ratio that give me the same 1/4 miles time. Strange?!!? Why a smaller motor will has a wider power band?

One conclution I can see from this calculator was it's a big advantage of try to go higher in voltage to have a wider power band. In my case go to 54s 7P vs 48s 8P would be a great advantage. What do you think?





duncan said:


> No reverse just push it back


Hahahaha!! I like your idea, but I think the idea to use a old reversing forklift contactor will be the better one.




dimitri said:


> I would recommend to design your battery pack such that you can add more cells in parallel to existing 48 groups later on, if/when you realize you need more capacity to get your range, so you can get from 48S8P to say 10P or 12P without having to redo a lot of work.


I don't have the space and the money to put more cells in paralel. If My calcul is right I will need around 80A to drive at 50mph and that give me a range of 40 miles at 80% DOD. So if my range will be less than 40 miles I can't do anything and I will do with. Less range maybe, but it's less money for an electric car and that is the most important thing.



Well, in conlusion, because the Crown motor is around 80% of the lengh of a Wrap 11 or similar motor I think I need a bigger motor to perform a realy fast 0-60 mph. The torque capacity of this short Crown motor is probably more comparable to a Warp 9 and it isn't what I need.


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## Duncan (Dec 8, 2008)

Hi Lloydn

*and an estimate of 60% weight on the driven wheels (627kg)

627 * 0.8 = 501.6N
*

You changed units from Kg to Newtons - 1 kg exerts 9.81 Newtons downwards due to gravity (I normally use 10 as a conversion)

This becomes

and an estimate of 60% weight on the driven wheels (627kg)

627 * 0.8 = 5016 N

Which means that you should be able to spin the tires in first gear but probably not in second!

My "car" (partly built)

Vehicle weight - 650Kg / 50/50 weight distribution 325 Kg on back wheels
325 x 10 x 0.8 = 2600N

or 325 x 2.2 x 0.8 = 572 lbs force

Tires are 1 ft in radius therefore 572 ftlbs torque

Final drive 4.1 : 1 

prop-shaft torque required is 572 / 4.1 = 140 ft lbs

I have a 48volt 10Kw Hitachi forklift motor - 11inches diameter 14 inches long weighing 102 Kg

I think (guess) that it will be comparable to a Warp11 
The Warp11 graph goes to 140 ftlbs at about 450 amps

So I decided not to go for a gearbox!

I have ordered an OpenRevolt controller kit - 500 amps

I don't know what max revs - 5000rpm is about 80 mph - should be good enough - if I blow it up I will have to find another one!!


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## Yabert (Feb 7, 2010)

Hi all

What do you think about dual motor. Something like one 8" motor coupled to each rear wheel by 4:1 ratio.
I have 350$ budget for a helical LSD, but with two motor, I don't need LSD. I only need to coupled each motor in parallel (500A, 154v each) and they give me similar torque to each tire. This set-up will probably weight a bit less than big 11" motor+ helical LSD, but I'm not sure about power capacity.

Comment?


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## lloydn (Dec 8, 2009)

Thanks Duncan, I see I mixed up weight and mass. That gives a more reasonable number. 

It's surprisingly hard to find good numbers for static coefficient of friction on the internet. I've seen anything from 0.7 top 1.0 for normal cars on dry tarmac, and 0.3 to 0.8 for wet. 

I think it's quite important to include weight transfer if you are using the equation you are, as most of the recorded acceleration times, especially of RWD cars, are not possible with the equation as it stands. For Yabert's Smart, it would mean 0-60 in less than 7s is impossible. 

Regarding battery setup, I just had a look at the Kelly website, and the max operating voltage is 180v. A 48s pack is the maximum you can really run for that, charging each cell to 3.75v. If you put any more in series, then the Kelly would not work with the fully charged voltage. 48s8p is a good set up though. 

If your motor is 80% of the size of a warp 11, and if you get 80% of the torque, then you should get better than your required acceleration (less that 6s 0-60 if you're lucky). The big two ifs are if the motor is like a warp11 with 80% torque, and can the smart put the torque down? Only way to find out is to test it really. 

Range wise, I think you'll make your 40 miles quite happily at 50mph, though I don't have a calulator worked out for a real driving cycle. That's just calulcated from rolling and air resistance, and 80% of the charge of the battery. 

You might want to consider a seperate fan for cooling the motor, for low speeds, and it can't hurt when driving it harder too. 

If you can fit the two motors and gearing, that might be a viable option too. It might be hard to get two reasonably well matched motors.


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## Duncan (Dec 8, 2008)

Hi Yabert

Which diff are you looking at - I just scored a complete front and rear setup including an LSD for a Subaru for $200

Subaru LSD's seem very common here - they are made by Fijutsi Heavy industry and I think are used in Nissan's as well

If you get a cheap LSD - a single motor would be easiest - (my motor cost $100 - did I say I am a Scotsman?)

Hi Lloyd
Weight transfer (fore-aft)
Force at tire contact x height of center of mass = wheelbase x wt transfer

So a dragster can have a high C of G, 
I like cornering so I am going for a low C of G 

For my car which is quite long with a very low C of G it gave very little weight transfer - I think it was 10%

_It's surprisingly hard to find good numbers for static coefficient of friction on the internet. I've seen anything from 0.7 top 1.0 for normal cars on dry tarmac, and 0.3 to 0.8 for wet. _

Thats what I found which is why I went for 0.8 - for cheap tires (did I say I am a Scotsman?)

I don't think less than 7 seconds to 60mph and cheap tires go together!!


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## MalcolmB (Jun 10, 2008)

Yabert said:


> What do you think about dual motor /snip/ I only need to coupled each motor in parallel (500A, 154v each) and they give me similar torque to each tire.


Dual motors sound good. I've also been considering running two motors in parallel but recently saw this comment from CroDriver that left me a little uncertain: (http://www.diyelectriccar.com/forums/showthread.php?p=208510&highlight=parallel#post208510): "the problem is that there is no way to make both motors perfectly same, the wires are not the same and the connections are not the same. There will always be a different resistance from the controller to the motor. That will kill one motor if you're close to the limit of both motors. That happened to me. I fried one motor while the other one was like new."

I guess the only way to find out is to try for myself, but I will definitely be making cables exactly the same length and installing a pair of ammeters on the dash to monitor both motors carefully.


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## rwaudio (May 22, 2008)

MalcolmB said:


> Dual motors sound good. I've also been considering running two motors in parallel but recently saw this comment from CroDriver that left me a little uncertain: (http://www.diyelectriccar.com/forums/showthread.php?p=208510&highlight=parallel#post208510): "the problem is that there is no way to make both motors perfectly same, the wires are not the same and the connections are not the same. There will always be a different resistance from the controller to the motor. That will kill one motor if you're close to the limit of both motors. That happened to me. I fried one motor while the other one was like new."
> 
> I guess the only way to find out is to try for myself, but I will definitely be making cables exactly the same length and installing a pair of ammeters on the dash to monitor both motors carefully.


If you don't already have the controller you could do what Crodriver recommends and put the motors in series, and use a higher voltage lower current controller. That way both motors get the same current, regardless of load/rpm/traction/motor differences etc. Total power can remain the same, and for reliability it seems like a good choice.


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## Yabert (Feb 7, 2010)

I have the controller right now! 180v max. I will charge each cells at 3.65v, but it drop to around 3.34v after I stop charger.

At 1000A connected the motor in series this give around 65 volts to each motor. It's probably not enought to sustain the max torque at least to 60 mph.


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## rwaudio (May 22, 2008)

Yabert said:


> I have the controller right now! 180v max. I will charge each cells at 3.65v, but it drop to around 3.34v after I stop charger.
> 
> At 1000A connected the motor in series this give around 65 volts to each motor. It's probably not enought to sustain the max torque at least to 60 mph.


That's too bad, you are correct the voltage wouldn't be near enough in series. If you did have the voltage though, 1000A through both motors would give you lots of power in a little car. (if you could keep the tires from spinning uncontrollably that is)


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## Yabert (Feb 7, 2010)

I got the cells!

Total of 338 cells buy direct from Headway. It's like they have a new style of positive terminal!
I tested around 10% of the cells and all are between 3 and 3.5 mΩ. 

The price is around 17$ each including shipping and taxes.

I need to add 46 cells from my motorcycle pack to complete my 48s 8p pack.

So 1000A / 8 = 125A
125A x 0.0035 mΩ = 0.4375
3.2 - 0.4375 = 2.76 v

And (2.76 x 48) x 1000 = 132.48 KW peak...... not bad in a Smart Fortwo!


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## jackbauer (Jan 12, 2008)

Be very careful of those JC23 coded cells. They have no rupture disc. See my thread :

http://www.diyelectriccar.com/forums/showthread.php/headway-hell-51847.html


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## Yabert (Feb 7, 2010)

Hi
My 38120S 10Ah are coded JI03 and JI04. The first box contain a warning paper about too long screw they push on rupture disc.


And after many weeks of search and design about limited slip drive train I finaly concluded that will be realy complex and costly to build a custom direct drive lsd drive train. It's easy in a motorcycle or a go-kart, but it's another way in a car.
So now, the best way I find is use a Sentra SE-R Spec-V transmission. They come stock with a helical lsd (Torsen) and have 6 speeds. 
I think use the 4e and 5e gears to have a 4.378 and 3.345 ratio. I can get one at scrap yard for 300$.
After some calculs, that give me the same 0-60 mph time than direct drive set-up cause by the 0.5s shifting delay. So a faster 0-45 mph, same 0-60 mph and a faster 0-75 mph and 1/4 miles.

I'm a bit disapointed to don't go direct drive, but I know it will be probably a bit more efficient and a lot less complex. So it's not bad.... I think!


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## Yabert (Feb 7, 2010)

The small 800cc CDI diesel motor is out of the frame. It haven't a lot of place for a big 11" motor and a Nissan transmission.....
The ICE is put at 45° in the rear of the Smart and pass over the drive shafts. So, replace it for a big 11" cylinder will be not easy!!


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## tomofreno (Mar 3, 2009)

> So, replace it for a big 11" cylinder will be not easy!!


 I'll say. This will be interesting to watch! How are you going to keep the front end on the ground when you floor it?


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## Yabert (Feb 7, 2010)

tomofreno said:


> I'll say. This will be interesting to watch! How are you going to keep the front end on the ground when you floor it?


I will don't have race tire on, so no problem.... the car will be a doughnut machine.


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## Yabert (Feb 7, 2010)

Hi

What do you think about this insulating varnish to insulate a bit more an old GE forklift motor?
It is pretty cheap at less than 10$ for an Aerorols. 2900 volts per 0.001".


PERFORMANCE​ 
*TEMPERATURE CLASS: *
Class F (155°C / 310°F)​*DRY HEAT RESISTANCE:*
Constant: 310°F
Intermittently: 400°F
*DILECTRIC STRENGTH: *
(ASTM D 115-07)
Red: 2,600 VPM
Green: 2,890 VPM
Clear: 2,300 VPM


*ONE WEEK HARDNESS: *

(ASTM D 3363 SHORE A 24hr / 1 Week): 6B

*FLEXIBILITY:*​(ASTM D 522) Pass 
*CHEMICAL RESISTANCE:*​Aliphatic hydrocarbon solvents: Moderate
Alkalis: Severe
Aromatic hydrocarbon solvents: Severe
Chlorinated solvents: Moderate
Salt water: Severe
Glycol ethers, alcohols: Severe
Inorganic acids: Severe
Organic acids: Severe

Oils: Severe


DRYING SCHEDULE​ 
*DRYING TIME AEROSOL @ 70°F @ 50% R.H.:*​To Touch: 1 Minunte
To handle: 5 Minutes (Tack Free)
Full cure: 7 Days

*DRYING TIME BULK @ 70°F @ 50% R.H. 1mil wft:*
To Touch: 10 Minutes
To handle: 1 Hour (Tack Free) 
Full cure: 7 Days

Curing can be accelerated by baking for 1 hr @ 300 degrees F
*RECOAT: *Anytime​


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## Yabert (Feb 7, 2010)

Duncan said:


> I have been thinking about the reverse gear issue - for a lightweight 2 seater
> 
> (1) -No reverse just push it back
> (2) - Use the reversing contactor I got from an old forklift - should never be actuated under load
> ...


I have another idea to put on the table about reversing motor rotation in a direct drive application.....

What do you think about add another small controller to the motor? 
I have a 156v 1000A controller to go forward and I think about a cheap (100$) 12v 200A controller to go in reverse!

This configuration have the the important advantage than no power is lost in the reversing contactor. Why lose 100% of the time 0.5% of your power in the contactor (even more in stop and go in the city traffic when motor often see 1000A) when you only need this contactor to go in reverse 0.5% of time during a ride?

I only need a good auxiliary battery coupled with the DC-DC. 200A is less than an engine starter need during some sec.
Or, if that exist, I need a small 156v 200A controller!
In fact, I'm not persuaded I need 200A to go in reverse at 5 mph during 5-10 sec.

What do you think about this solution to go in reverse?


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## MalcolmB (Jun 10, 2008)

Sounds like a good alternative to me, in fact I might just do the same myself. It means a small weight penalty, and a little more complexity, but like you say it eliminates voltage drop across the reversing contactors. With a car that is as short as your Smart (and my Mini) it's not as if we'll need to reverse very often  You might want to avoid parking facing down a steep hill though, just in case someone parks right in front of you...

Were you thinking of using the same throttle potentiometer for both controllers?


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## major (Apr 4, 2008)

Yabert said:


> I have another idea to put on the table about reversing motor rotation in a direct drive application.....
> 
> What do you think about add another small controller to the motor? .....
> What do you think about this solution to go in reverse?


Hi Yab,

I don't see it  How do you connect a second controller to a series motor and get reverse? You still have to reverse the field respective to the armature. And once you do that, just use you main controller.

Regards,

major


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## MalcolmB (Jun 10, 2008)

Ahem, yes, uh, I knew that of course ...

... another mince pie and a glass of sherry for me, Nurse


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## Yabert (Feb 7, 2010)

> How do you connect a second controller to a series motor and get reverse? You still have to reverse the field respective to the armature.


 
Eeeeeh!! scheize!!...

I haven't thinked enough before write my question.
The problem is the A2-S2 connection. I can put a small contactor (200A) between S1-S2, but I can't disconnect A2-S2 without a big contactor (1000A). 
And 4 kilovac EV200 contactor cost 500$......

I can't believe it's that costly and complex to go in reverse!


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## rwaudio (May 22, 2008)

The cheapest you could get away with are two big contactors to disconnect S1 and S2 then two small contactors to connect the field the other way.

There are some EV200's on ebay, I don't know the seller but the price is good.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190471372342&ssPageName=STRK:MEWAX:IT

Good luck!


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## pm_dawn (Sep 14, 2009)

Hi !

Why not build a small friction drive, just like a caravan mover.
http://www.powrwheel.com/
Run it off 12v I vould guess a high quality cordless drill would do the job.

Regards
/Per Eklund


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## caca (Feb 10, 2009)

Hello,

This is a great project and something like that I want to build. My dream car would look something like this;

- Smart 451
- Soliton Jr. controller
- Kostov new 9" 220V motor
- 69s5p Headway 40160s 16Ah, which is approximately 18kWh and 175kg

Yabert, I wonder if you measured the space for batteries, what are the dimensions of space. I plan to put the battery in this place.











My battery configuration



















the entire battery pack would be about 600 x 800mm and 200mm high with battery box


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## Woodsmith (Jun 5, 2008)

pm_dawn said:


> Hi !
> 
> Why not build a small friction drive, just like a caravan mover.
> http://www.powrwheel.com/
> ...


I was thinking of a small geared motor with a sprocket to engage the chain on my trike to get reverse. I figured in the same way that motorbike converted trikes do it. Might even get away with no controller, just a big switch, though a small 12v bike controller would do.

The other option I thought about would be a big double pole change over switch.
I'm sure you could make one with a rotary barrel, like they did on old electric milk floats, and it wouldn't need to switch a live current so no arcing to worry about.


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## Woodsmith (Jun 5, 2008)

It occured to me, as I was in the shower just now, that I have a shed load of 200A-300A 440Vac switchgear.
I should be able to find parts to make a usable reversing switch on the basis that it only needs to carry the dc current but not switch it. It will only ever operate when the current is zero so no arcing problem. It can also have a built in throttle pot cut off to kill the controller before it breaks the contacts.

That maybe your solution to an affordable reversing switch too.


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## nimblemotors (Oct 1, 2010)

Cool project. Why can't you fit a FWD transmission in it? Does the smart have an existing trans? A Geo Metro 5-speed is quite small and light,
you might even think of using an Automatic version so the manual shift linkage isn't an issue to get into reverse.

Why such a big deal to avoid using reversing contactors?
They are used commonly with DC motors.


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## Yabert (Feb 7, 2010)

caca said:


> Hello,
> 
> This is a great project and something like that I want to build. My dream car would look something like this;
> 
> ...


 
Really nice picture!!...

I will put all the battery at the same place. The Smart engineers will also put the battery box at this place.
The green area on your picture mesure aproximately 500mm x 1030mm x 200mm.

So you can't put 18Kwh of energy with todays battery technologies. I will put 48S 8P of headway 10Ah 38120S for 12.3Kwh and it's realy tight!

But your set up will be awesome with Smart/Soliton Jr/Kostov 220v and probably a bit less Kwh. If you don't need great performance you maybe can find less powerfull battery with a bit more wh per liter (more kwh for same space but less Kw).


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## Yabert (Feb 7, 2010)

nimblemotors said:


> Cool project. Why can't you fit a FWD transmission in it?


Too big. The Nissan sentra Spec V transmission is really too big!



> Does the smart have an existing trans? A Geo Metro 5-speed is quite small and light


They can not transfers 250-300 lbs-pi of torque produce by the motor.



> Why such a big deal to avoid using reversing contactors?
> They are used commonly with DC motors


Yes, but not at 1000A


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## nimblemotors (Oct 1, 2010)

ok, so your going too big and too fast  
Note that the axles/hubs themselves may not be able to take a lot of power, these cars only have 3 lug nuts!

This car might be a good candidate for a EV drivetrain that I've have been contemplating that has never been done before. Something similiar was tried with a Tucker in the 40's, but the motor was not powerful enough.
This isn't a problem with a big max-torque-at-zero-rpm electric motor!

The idea is to use one big electric motor in a direct drive fashion and have its shaft drive each wheel.
To get the differential and a form of gearing, use TWO torque converters, one on each shaft, and the output going to the wheels.










Of course this will involve a lot of custom fabrication to get an existing torque converter configured to work this way.
I would love to find someone willing to fund the construction of such a drive system. 

My other suggestion would be to use a IRS differential e.g. a Ford Tbird or older Corvette, rotated upside down so the motor will mount out the BACK and not the front. The motor will then stick out behind the car, but you could dress it up somehow to hide it, maybe add some bodywork to make it look like a "continental spare" spare tire back there, or a hump trunk like some old 30's cars.

Jack Murray
Nimble Motorsports



Yabert said:


> Too big. The Nissan sentra Spec V transmission is really too big!
> 
> 
> 
> ...


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## Woodsmith (Jun 5, 2008)

Yabert said:


> This configuration have the the important advantage than no power is lost in the reversing contactor. Why lose 100% of the time 0.5% of your power in the contactor (even more in stop and go in the city traffic when motor often see 1000A) when you only need this contactor to go in reverse 0.5% of time during a ride?


I keep reading this and wondering where this 0.5% loss is from that you are worried about.
Is it the power in the contactor coil energised to go forward?

If it is it has made me think about mine a lot, lower power but also not wanting to lose what little I have to heat a contactor coil 99.9% of the time.

On my tractor I have these DPST for the reversing contactor.








One has to be energised for forwards, the other has to be energised for reverse so there is always power to the coil to move.

I also have a pair of these change over winch contactors to low power test with.









I will upgrade to this Albright type. Not sure if you can get this type for 1000A though.









I can use this wiring method so that neither contactor is energised to go forward but both are energised to go in reverse.


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## MalcolmB (Jun 10, 2008)

Maybe I can redeem myself for my senior moment earlier...

The losses are due to the resistance of the contacts in the reversing contactor. The typical voltage drop across the contacts is 40 mV per 100A according to the Albright data sheet (http://www.thetoolboxshop.com/sw202...olenoid-contactor-12v-intermittent-5246-p.asp)

Since each reversing contactor has two set of contacts the total voltage drop is 80 mV per 100A which means 0.8V at 1000A, so 800W of losses. You'd naturally only see this loss for a short time. When cruising at 100A it drops to 8W.


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## Woodsmith (Jun 5, 2008)

Ahhhh, my senior moment maybe.

I wasn't aware the contact losses would be sooooo great! Wouldn't that hold true for all the contacts and how would that compare to the rest of the losses?

Would a solid state switch be any better? I know some winch suppliers are also looking at mosfet switching to replace the traditional contactor banks.

Maybe there would be a market for such things for EV use?


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## Yabert (Feb 7, 2010)

MalcolmB said:


> Since each reversing contactor has two set of contacts the total voltage drop is 80 mV per 100A which means 0.8V at 1000A, so 800W of losses. You'd naturally only see this loss for a short time. When cruising at 100A it drops to 8W.


It's exactly what a talk about!.... But do you add a zero?.... 80mv is 0.080?

Well it's why I think you can lost a lot of power in urban trafic when you often stop and go (when motor often see high amp).

Kilovac EV200 is rated:
Contact Resistance, Typ. (@200A) mohms 0.2

So it's 200 x 0.0002 = 0.040v x 200A = 8w @ 200A and 200w @ 1000A

Is that correct?????


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## MalcolmB (Jun 10, 2008)

Yabert said:


> It's exactly what a talk about!.... But do you add a zero?.... 80mv is 0.080?


I don't think so...
For the Albright reversing contactor, total voltage drop is 80mV per 100A, so 800mV at 1000A, which is 0.8V = 800W power loss.

You would need three EV200 contactors to replace this, in which case the total power loss at 1000A would be 600W.


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## nimblemotors (Oct 1, 2010)

The contactor losses are almost nothing compared to the power used to move the car. 1000amps * 144v to move the car = 144Kw !
If you are concerned about this minor detail, you can use an AC motor that can regen for braking, that is many times more important than contactor losses. 



Yabert said:


> It's exactly what a talk about!.... But do you add a zero?.... 80mv is 0.080?
> 
> Well it's why I think you can lost a lot of power in urban trafic when you often stop and go (when motor often see high amp).
> 
> ...


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## Yabert (Feb 7, 2010)

nimblemotors said:


> The contactor losses are almost nothing compared to the power used to move the car. 1000amps * 144v to move the car = 144Kw !
> If you are concerned about this minor detail, you can use an AC motor


 
Yes... certainly! 

But the budget for my 100Kw drivetrain (Kelly KDHD and forklift motor) is 2000$

Not exactely in the AC range..

So because this cheap drivetrain have around 92% efficiency (98% controller, 86% motor) I try to minimise the lost where it isn't necessary.


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## rwaudio (May 22, 2008)

Yabert said:


> Yes... certainly!
> 
> But the budget for my 100Kw drivetrain (Kelly KDHD and forklift motor) is 2000$
> 
> ...


efficiency's don't "average" that way.
it would be 98% OF 86% which is 84.3% not 92%
hope that helps.


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## Yabert (Feb 7, 2010)

Yes! thanks

The average is 92%, but I understand than xxx watts lost + xxxx watts lost can't give less watts lost!.. So 84.3% is right.


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## nimblemotors (Oct 1, 2010)

I was under the impression this was high-power fast car, why are you worried about stop-n-go optimization? 
If doing the drivetrain on the cheap there are always compromises.

You could add a second AC motor that does the regen and reversing to the big DC motor. 
As I see it, your major problem is the transmission right?



Yabert said:


> Yes... certainly!
> 
> But the budget for my 100Kw drivetrain (Kelly KDHD and forklift motor) is 2000$
> 
> ...


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## MalcolmB (Jun 10, 2008)

nimblemotors said:


> The contactor losses are almost nothing compared to the power used to move the car. 1000amps * 144v to move the car = 144Kw !


But most of the time the motor sees close to 1000A it is likely to be at very low speed, so the voltage will also be very low. The losses in the contactor will then be a much higher proportion of the power output.

On the other hand at that current level, motor losses will far outweigh contactor losses.


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## Yabert (Feb 7, 2010)

nimblemotors said:


> I was under the impression this was high-power fast car, why are you worried about stop-n-go optimization?


In fact, even if you have a sport car able to do the 0-60 mph under 6sec, you always need to stop at the red light when you go at work!!..


I have a question about fuse....

I have a cheap ANL/CNL fuse rated 80v and 400A from my motorcycle at home. What happens if I will put it in serie to test my 156v battery pack?
It will blow immediately when I put more than 80v?
It will blow at lower amps (ex. 250A)?
Or ??????


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## major (Apr 4, 2008)

Yabert said:


> I have a question about fuse....
> 
> I have a cheap ANL/CNL fuse rated 80v and 400A from my motorcycle at home. What happens if I will put it in serie to test my 156v battery pack?
> It will blow immediately when I put more than 80v?
> ...


Hi Yab,

The fuse will still blow at 400 amps. Well slightly above that. Or greater. But the trouble is that it is only rated at 80 volts, so it might not blow, or blow and weld back together because it is arcing. And the fuse maker will say you have incorrectly applied it using it at a higher voltage than his rating, and he is right.

Fuses might work at higher than rated voltage, or they might not. Don't bet your life on it 

major


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## Yabert (Feb 7, 2010)

I have a new question for my project...

I think use 3 board of the mini BMS centralized with KP-D(1500W) Charger for my 48s battery pack.
The charger put out 7.5A continuously and 0.75A when it limit the voltage and the mini BMS shunt capability is 0.75A.

So, what happen when the charger will be in limiting voltage and 0.75A?

The mini BMS shunt will heat all the week because the cells never see the high voltage limit (3.6v)?
Or......?..


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## Yabert (Feb 7, 2010)

I just got my motor!!..

It is in really nice shape! On the name plate it's Crown, but I thinks it was made by GE or some other compagnie. Part number is W11AB02. It's an 11" motor, but it is 2" shorter than a Warp 11 and it has 49 bar on the armature.
It's rated 9.6 Kw for 1h at 48v..... so around 30 Kw at 150v. Well, exactly the Smart CDI was rated.

I think try to generate 100 Kw from this motor....

The original weight was 240 lbs with rear brake. I think I will be able to reduce his weight under 200 lbs with many modification.


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## Yabert (Feb 7, 2010)

It's time for few update.

I started to rework the motor. I added red insulating varnish on armature near the brush. I also add some turn of Fiberglass Cloth Insulating Tape on bars to improve strenght. I also clean the commutator, take out many useless steel and remove the fan.

No more problem with reversing contactor!! The transmission choise is done! It's a Volkswagen 02J come from a VR6 Jetta. The third gear give me a great 5:1 ratio for awesome acceleration and I think use the 4e gear (3.52:1) to go over 60 mph.

About the coupling of the motor and the transmission, I can say the motor front flange will be at the same time the adapter for the transmission.
The motor shaft will be coupled with the cluch hub by the front of the 50mm shaft.
If you think it's a weird mecanical coupling....... you are right!
But I don't have a lot of place (for keyway, keyless bushing or ??) and it's why I do this. You can see in the drawing than the armature come inside the bell housing!!! Strange design? Hum! YES!!

Also, if you think the drive shaft come in interference with the motor housing...... you are right!
I need to rework the housing a bit to do free space for the drive shaft.
Isn't complicate to understand.... an 11" motor normally don't fit on a conpact car transmission!!!!


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## rwaudio (May 22, 2008)

Let me see if I understand this correctly, you removed one of the end plates of the motor, and you are designing a new end plate that doubles as the adapter plate?? Very interesting!!

I can't wait to see how you integrate it into the car. Personally I wouldn't take a random transmission and try to integrate it into another car, however I bet your finished product would pass for factory.


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## Yabert (Feb 7, 2010)

Some work advancement.

-The steel coupler for the motor shaft to the cluch is done!
-Drive shaft flange are ready. Custom flange from Smart fortwo shaft to Volkswagen transmision.
-I received aluminum parts from water jet cut! (laser cut and water jet is so awesome!!) I need to rework both parts to fit on the motor housing and the transmission.


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## Yabert (Feb 7, 2010)

The motor/transmission assembly is in the car!

You can see below the adapter for the transmission who is also the motor flange.
I do a pocket on the motor housing to pass the axle shaft..... one more time, an 11" motor is too big for a compact car transmission (Volkswagen 02A).

I need to rework the axle shaft before I can move the car by itself.


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## Woodsmith (Jun 5, 2008)

Yabert said:


> one more time, an 11" motor is too big for a compact car


I can't imagine why you would think that!


Great bit of machining there, looks very pretty.


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## Yabert (Feb 7, 2010)

Only few days before first test drive at 64v 10Ah!!

Finally, after few modifications, the motor weight 200 lbs (vs 240 stock with brake).

I think it’s not bad for a 250$ motor, but I think the weight/power ratio will be ordinary (more bad than Warp9 for example).

I also paint the motor. Insulating varnish inside and nice color outside!

I add spacer bellow the polar core (stator poles) to reduce the air gap between armature and stator. From 0.066” stock to 0.035” now. Anyone know what kind of percentage efficiency/torque/advantage that change will do? I see at many places that help, but how much?

What about this formula: GAP, inch= 0.005+ 0.0003 D+ 0.001 L+ 0.003 V
0.005 + (7.375x0.0003) + (4.515x0.001) + (6.76x0.003) = 0.032”

One axle shaft has perfect lenght and I shorted the second. I hope it will be support the high torque from motor.


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## rwaudio (May 22, 2008)

very nice work!

Can't wait to hear how it drives!
I just completed similar 50v 10ah testing so that I could confirm the 2nd to 3rd shift would work since I ditched the clutch.
Works like a charm sofar! Coupler is going back for some rework though.


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## Yabert (Feb 7, 2010)

rwaudio said:


> very nice work!
> Can't wait to hear how it drives!


 
Thanks... and see bellow:

http://www.youtube.com/watch?v=La7nST0w38M

The car moves!

I do a small turn in few streets with a 64v 10Ah battery pack..... at 20 mph....

The controller was set at low power and I recorded 250A on the motor side and only 80A (8c) on the battery side. 
So, theorically that give around 4-5 hp... that explain the 20 mph top speed.

At 250A the rear wheels don't spin, but the torque is able to doing slip the front wheels on the pavement when I push the brake and the accelerator in the same time... This is promising!


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## rwaudio (May 22, 2008)

Yabert said:


> Thanks... and see bellow:
> 
> http://www.youtube.com/watch?v=La7nST0w38M
> 
> ...


Very nice! I'm sure you get to 20 pretty quick though and just run out of power. The drive train looks pretty nice though, just by looking at it I wouldn't have guessed that's a VW transmission, it fits nice and looks good. How does it "feel"? My 944 transmission makes more noise than the motor.


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## Yabert (Feb 7, 2010)

rwaudio said:


> Very nice! How does it "feel"?


It feel like a big golf car at this moment!! All other cars are faster than me and come close to my back window after each stop.
I'm impatient to have more power than majority of the others cars!!


I have some others results after one more test at 64v 10Ah.

Some impressive max speed numbers.... 

2 gears: 20 mph
3 gears: 24 mph
4 gears: 22 mph
5 gears: 20 mph

Hey! RW, I realy appreciate what we can read on your blog. Thanks!


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## rwaudio (May 22, 2008)

Yabert said:


> It feel like a big golf car at this moment!! All other cars are faster than me and come close to my back window after each stop.
> I'm impatient to have more power than majority of the others cars!!
> 
> 
> ...


That's pretty much how mine was, however I live in a playground zone so the limit is 30km/h for most of the block anyways, I topped out at just shy of 40km/h (so probably about 24mph as well). I can't wait for a larger pack! I assume you have no power steering or A/C? What are you doing for heat?


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## Woodsmith (Jun 5, 2008)

Really liking that, even at 20mph.
Well done, that is an impressive looking installation.


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## Yabert (Feb 7, 2010)

rwaudio said:


> I assume you have no power steering or A/C? What are you doing for heat?


You are right, the original Smart come without power steering and with no AC.

About heating, I think integrated an Easy Heat heating cable (126w) inside the battery box and put an 1500w or 3000w water heating element in the original hot water circuit. I will need to add a pump in the curcuit.


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## Yabert (Feb 7, 2010)

Well, really long time without posted!!

I passed the summer to design a f***ing battery pack able to perfectly fit under the small Smart Fortwo. Don't cutting any original body part to fit the pack is a real challange.

Exept that, I flirt with the idea to use the newly available A123 20Ah cells, I rethink about my 48s charging systems and I reworked my motor to stop vibration.

And now, the battery pack is under build. I expect put this one under the car this week end and try the car at high speed without abuse too much the news cells and the motor. (400-500A limit).
Pic of the assembly soon!


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## rwaudio (May 22, 2008)

Yabert said:


> Well, really long time without posted!!
> 
> I passed the summer to design a f***ing battery pack able to perfectly fit under the small Smart Fortwo. Don't cutting any original body part to fit the pack is a real challange.
> 
> ...



Very nice! When do we get to see pictures of the real thing? I enjoy comparing your renderings to real life, they match so closely. What type of problem did you have with the motor?

I kind of wish you went with the A123's then I could benefit more from your engineering skills. I received my 2nd batch today, bringing me up to 245 cells. 

I can't wait to see how your car does on the highway.


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## Yabert (Feb 7, 2010)

Preparing of 384 headway cells...
Remove originals screws, tested and put a set screw with lock tight.










Empty battery pack take his place under the car.










Headway cells holder.


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## Yabert (Feb 7, 2010)

*Question for you*: How many time do you need to complete the assembly of a 12.3 kwh battery pack with headway cells (more than 1300 parts)?
*Answer*: A lot and a lot!!!!..

Three continous days of working wasn't enough to put the battery pack under the Smart to do a test drive on the highway. Friday night to monday night of work with a friend and the pack isn't currently complete. 

Tonight, I think about large prismatics cells!!! Trust me!! _(Hummm! 48 rectangular plastic block with only two terminal)._
A good advice: If you have the extra space to put large prismatic in your car and if the extra weight isn't a real problem, go ahead with large prismatic cells! It's so much less trouble.

Well, I present the assembly in pictures.
You can see all we need to build that kind of battery pack: 384 10Ah cells, battery box with side and cover, bus bar, a lot of screw, orange cells holder, thread inserts, connectors and many tools.

To start, I put an insulating paper on the aluminum box and I add an 1/8'' rubber sheet.
After we start the assembly on a table. When the assembly coming over 100 lbs, we continue in the battery box.
I don't finish to build the 48 wires and connectors needed to charge the pack and it's why I have build a temporary 8s charger.

Now the battery pack have his sides and his cover, so the next step is to complete the wiring and put this 300 lbs energy storage unit under the car....


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## Jimdear2 (Oct 12, 2008)

Yabert,

We recently designed and assembled a similar but smaller pack of 150 38120S cells in a 3P/50S configuration (pack was designed as 4P/50S and will be updated this winter). We also used the Headway assembly blocks.

We ran into a number of quality issues and wondered if you has seen any of those same issues?
Here is a list:

1.) Cell electrolyte leakage,
2.) Negative end turns in the cell before the specified torque is reached when setting cells in series
3.) The black potting material sealing the negative end popping out 
4.) Mis-drilled/tapped holes in the negative end blocks of the cells
5.) Blue plastic body covering peeling away because of assemble blocks 
6.) Slight differences in the assembly blocks from different manufactures
7.) Batteries that self discharge to less then 1 volts after being cycled a few times and won't recover
8.) Large variance in internal resistesnce

From your assembly sequence pictures you appear to have had a straight forward time of it. 

We were not so lucky I ended up buying many extra batteries (20 or so) to overcome the the different problems noted. 

My re-seller offered no warranty other then DOA, I went with them because they were very highly recommended. I accepted their terms with eyes wide open so I don't feel wronged

If you have had any of the same problems I hope you would join me in recommending that future buyers of Headway cells insist the re-sellers warrant the noted problems.

We have been quite pleased with the performance of the cells themselves, the amount of power available is amazing. The data extractions from the few runs we have made show no real strain maintaining the loads we have been able to supply. Just about the time we think we might have enough load to start sagging the battery to it's knees it comes back for more.

One thought that came to mind when we assembled the pack using the Headway assembly blocks was heat extraction, The cells heat up quickly under loads, both charging and discharging. For us with our 15 to 20 second runs it's not too bad, I don't know how the heat will affect your pack design, but be aware there might be a heat problem.

You may know that we went with a different charging and BMS scheme. using individual chargers on each buddy stack. Our individual chargers are incapable of producing charging voltages over 3.5 volts and can put as much as 20 amps (we did limit the current) back into the 3 cell buddy stack. Using the 50 charger boards will allow each stack the battery to reach 3.5 voltage at its own pace. We use cell logs to monitor the cell stacks and turn off the 48 voltage supply to the chargers when all reach 3.5 volts. The cell logs also watch for low voltage events in each 3 cell stack (we have it set to 2.1 volts) under load and shut the entire battery off to protect the cells. For us this system is ideal, our on board charger weighs maybe 10 pounds complete and works with any DC source from 32 to 76 volts. We just have 4 big deep cycle batteries that we pull around on a wagon, this allows us to charge anywhere.

Anyway, we noticed bad heat buildups (we have a thermocouple in the middle of the battery) after we installed the battery cover. We have since installed two 90 cfm fans and opened the bottom of the battery case. It does help some 

Are you going the traditional route using bulk charging with some kind of shunting BMS

I've been watching your builds and have to compliment you on the quality.

Jim


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## rwaudio (May 22, 2008)

The pack looks awesome, but when you complain about the difficulty of the assembly, just think of the A123's and how many more parts you would have had and how much more complicated the assembly would have been. Not to mention the prep required for each cell. I envy the simplicity of your pack.
And as always the quality of the metal parts that go into your car!
I can't wait to a driving video.


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## Yabert (Feb 7, 2010)

Hi Jim

I have two experimentation with headway cells. First with my motorcycle battery pack and this one. All cells coming directly from china. First batch in mars 2010 and this one in november 2010.

So I will try to answer your question:

#1-2-3: Yes the negative end is a peice of crap. The positive end is strongly crimped in place, but the negative end seem only glue in place. The black epoxy fail and after the cells is no more seal causing electrolyte to leak. Also, the terminal can turn when the epoxy fail and I discover than when the terminal turn, the small foil inside will broke causing probably a really bad power capability (see pictures).
Those problems happen on few cells of the first batch order and on one or two cells on the second batch (I really take care).

#4: Not really. I have chance!

#5: Never on the negative end, but the crimping on the positive end cause the diameter to be bigger. Especially on my first batch order, less on the second order.

#6: I have order one complete batch.

#7: Not by themself. There are a lot to said about cells abuse to 0v, but not now.

#8: I suposed that kind of thing can happen with supplier. Personnaly, I ask to headway to have cells with 3.5-4 mohm and I received cells with 3.5-4 mohm.

I hope than Headway will change the negative end fabrication soon because it's really a problem. I can't understand why they don't put an interference in the cell body to block the rotation of the cell end. It's the main problem of those cells.

In picture, you can see positive end crimping, negative end without black epoxy, under the negative end,...and inside the negative end.


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## Yabert (Feb 7, 2010)

The project go ahead!

I completed the wiring for the charging/bms and I close the pack with his lexan cover. You can also see the black/orange wire who is a 126w heating cable.
I'm pretty happy of the pack density: 5572 cubic inch = 91.3 liter.... close to 135 wh/L including the battery box and probably around 90 wh/Kg for this 300-305 lbs battery pack.

Well the pack is in place under the car where a Smart is naturally build to receive a battery pack.


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## Yabert (Feb 7, 2010)

First try on the road yesterday with the new 154v 80Ah battery pack.... Many exitations and some surprises!

I can't reach more than 55 km/h (34 mph) on my 10 km round trip
The first reason is the bad throttle signal (0-5k). I can read only 260 peak amps on the motor side and only 90 amps peak on the battery side.
Well, I would need to modify something!

The second reason is the front brake are stick... Bad smell!

The third reason is the worst. The Kelly KDHD controller rated 1000A peak and 450A continous started to overheat after 1/3 of the trip at roughly 40 km/h (less than 150-200A continous)....
The massive heat sink don't seem enough to dissipate all the heat generate by this "ineffective" chinese peice. 

That seem be a really bad start for the Kelly... One more time, I'm so sad than the Soliton Jr wasn't availiable when I have start my project.


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## rwaudio (May 22, 2008)

Yabert said:


> First try on the road yesterday with the new 154v 80Ah battery pack.... Many exitations and some surprises!
> 
> I can't reach more than 55 km/h (34 mph) on my 10 km round trip
> The first reason is the bad throttle signal (0-5k). I can read only 260 peak amps on the motor side and only 90 amps peak on the battery side.
> ...



I hope you can get the throttle issue worked out easily and I hope the controller can do more than you described. That seems like very poor performance even for a Kelly. Can you get more airflow on it? Where is it mounted?


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## Yabert (Feb 7, 2010)

Pretty bad new tonight!

I found 156v between the controller positive therminal and the heat sink...and his support.... and finally the entire car!!!!!!! Oh! it's not good!

Can anyone confirm than it's 100% abnormal (controller fault).


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## powerhouse (Apr 1, 2011)

I dont know for sure, but im pretty sure that your heatsink shouldn't emit voltage!!


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## Woodsmith (Jun 5, 2008)

Looks wrong to me. I would expect the heat sink to be electrically isolated from the high voltage stuff, and possibly from the low voltage stuff too.

I would guess that it is faulty, either in isolation or via some other faulty component part.


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## pm_dawn (Sep 14, 2009)

i'm pretty sure Kelly has different versions, Isolated and non-isolated.

Check which version you have to see if it is supposed to be isolated.

Best Regards
/Per


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## Yabert (Feb 7, 2010)

Is there someone can see a direct relation between the controller overheating effect at only 150A continous (motor side) and the insulating problem?

As my test confirm, I needed roughly 14-15 hp (152v x 70-75A) to maintain 25-30 mph.

Is it bad to speculate than my car needed 8-9 hp at this speed, than my brake burning 2-3 hp, than the motor burning 1-2 hp and than the controller itself burning another 1-2 hp?


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## Brute Force (Aug 28, 2010)

Hi Yabert,

Yeah, that's abnormal. And dangerous.

Whatever you do, don't throw good money after bad. If Kelly replaces it under warranty for free, great. But if they offer to "upgrade" your controller for a nominal fee, cut your losses and get the Soliton instead.

Even if they do replace it under warranty, you should consider selling the replacement on eBay and getting the Soliton. You won't regret it.


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## Yabert (Feb 7, 2010)

Brute Force said:


> you should consider selling the replacement on eBay and getting the Soliton. You won't regret it.


I know...
Try to respect a tight budget can cause some bad decision. I regret the Kelly choise since a good time now.... and more than ever since a week.

*@ Gottdi:* Do you have the same casing insulating problem with your Kelly controller (800A I think?!)

I ask because Kelly answer to me than it's normal:

_Don't worry about it._
_That is our special design for Kelly controller._
_We installed a resistor between B- and case of the motor._
_It should be based on Mohm rating._
_Why did I add it?_
_It is used to add the electrostatic defending for our controller._
_As you know,it is bad for the controller if the electric charge accumulates too much without discharging._

I suspect they are a gang of ND!Mé≠!!?....


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## mrbigh (Dec 31, 2008)

Yabert said:


> I know...
> Try to respect a tight budget can cause some bad decision. I regret the Kelly choise since a good time now.... and more than ever since a week.
> 
> *@ Gotti:* Do you have the same casing insulating problem with your Kelly controller (800A I think?!)
> ...


_Kelly controllers??, a very bad reputation since a wile._


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## rwaudio (May 22, 2008)

Yabert said:


> I know...
> Try to respect a tight budget can cause some bad decision. I regret the Kelly choise since a good time now.... and more than ever since a week.
> 
> *@ Gottdi:* Do you have the same casing insulating problem with your Kelly controller (800A I think?!)
> ...


To confirm if they are full of _____ or not, disconnect power from the controller and measure the impedance (ohms) from B- to the case. If it's less than 10k I would say it's unsafe. If it's in the 1Mega ohm range I wouldn't worry about it. If it's between 10k and 1Meg it's probably safe but I don't think I would want it in my car. I'd get the Jr.


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## Yabert (Feb 7, 2010)

rwaudio said:


> That seems like very poor performance even for a Kelly. Can you get more airflow on it? Where is it mounted?


I know, it a really poor performance for any controller. If my memory is good, the really small Logisystems controller mounted on my motorcycle generated less heat at similar power.

It why I suspect this controller to overheating by himself.

The controller is just behind the driver seat:


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## rwaudio (May 22, 2008)

Do you have a fan or two on the setup?

Getting any kind of airflow over the heatsink will multiply it's effectiveness. 
Is the bottom of the kelly smooth and flat? Did it join nicely to the heatsink? Did you use heatsink compound?

This quote from the Kelly site leads me to believe they know you need extra cooling but don't tell you exactly how much.
_"Please note: 144V controllers generate large heat with high current. Need good size of heat sink and force air flow. Liquid cooling is preferred to get max power output."_


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## cbliss (Jun 28, 2010)

I saw the same thing on a couple Kelly controllers and contacted them and got the same answer, that they placed a discharge resistor to the case. If you disconnect power, and test, you will see no resistance in one direction and some in the other. The difference, would be that in one direction, it is trying to discharge and the other trying to charge the caps.

I tested on both series and bldc controllers. Same result.

While we could discuss the merits, it is clear it is "as designed".


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## Yabert (Feb 7, 2010)

rwaudio said:


> To confirm if they are full of _____ or not, disconnect power from the controller and measure the impedance (ohms) from B- to the case. If it's less than 10k I would say it's unsafe. If it's in the 1Mega ohm range I wouldn't worry about it. If it's between 10k and 1Meg it's probably safe but I don't think I would want it in my car. I'd get the Jr.


 
Good advice RW.

I record 13K ohm between B+ and casing and 24K ohm between B- and casing.
Safe??? Probably not because I discovered the insulated fault when I put the tool on the B+ terminal bolt and the other hand on the car frame.... strange sansation in my hand (electrical shock??)

I don't currenly have fan, but I can't beleive than this "156 Kw" controller need that much help to output 9-10 Kw (25-30 mph, low speed test).
At 98% efficiency that give only 200w of heat..... Too much for the large casing area + the very large heat sink?????
My small Logisystems controller on my motorcycle has less than 1/3 of this area to dessipate heat and it don't overheat at similar power (50 mph in motorcycle).

I will try some other test today with the heat sink insulate of the car frame.... detail soon.


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## rwaudio (May 22, 2008)

Yabert said:


> Good advice RW.
> 
> I record 13K ohm between B+ and casing and 24K ohm between B- and casing.
> Safe??? Probably not because I discovered the insulated fault when I put the tool on the B+ terminal bolt and the other hand on the car frame.... strange sansation in my hand (electrical shock??)
> ...


With those impedances it should be "safe" the worst you should feel is the sensation you described in your hand, probably a tingly feeling and not really pain. On the motorcycle I'm sure you had some air moving over the heatsink, even just from riding, that alone should be plenty to cool it. I would suggest even a 90mm-120mm computer fan would probably make a world of difference. Without a fan the bottom heatsink isn't going to do much, since convection won't carry the heat away, it will just rise up and stay within the heatsink fins. A fan blowing across the heatsink from side to side or even mounted under the bottom heatsink blowing air up into the heatsink would make a big difference.

Even though the Solitons have a BIG heatsink it wouldn't do much without the fans and even so they recommend water cooling in higher power applications.

Did you get the throttle issue worked out?


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## Yabert (Feb 7, 2010)

rwaudio said:


> With those impedances it should be "safe"


Thanks. Good to hear.




> On the motorcycle I'm sure you had some air moving over the heatsink, even just from riding, that alone should be plenty to cool it.


In fact, no! This one was under the seat without heat sink..... but anyway, read below...


Well, I do some preparation before the test:

-I resolve my sticking brake problem.
-Verify the flatness of the heat sink and the contact between this one and the controller.
-Fix the controller on the heat sink with six screw. Thermal paste between both for sure.
-I put the heat sink on a rubber sheet and I fix it with plastic cable ties.
-I unplug the accelerator pedale and put a small 0-5K pot on the pasager side.
-I programed the controller at 500A and full voltage (154 nominal) and I readjust the throttle input.
-I put my girlfriend behind the steering and I take the pasager seat with the 0-5K pot (yes, you are right, it isn't a realy safe situation...... not my girlfriend behind the steering, but me with the aceleration control on the passager seat..).

And go to the street. 

After few Km only, wow! This small car at 500A has a really good acceleration! The car move so much more freely than during the first test. I can easely reach 60-70 km/h before I hear an alarm sound (my girlfriend who said slowly...).
"We" drive few more Km before reaching our destination and the controller was only warm. I guess around 25-30°C comprare to around 50-60°C during the first test (I can't touch it for more than few sec by hand).

So, two thing:

-I greatly underestimate my sticking brake problem. Those ones probably take more power than I was thinking.
-I think than the controller can heat by itself cause by the grounding problem. Is it possible.
Someone have a physical/electrical explanation or if I'm wrong about this controller fault?


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## electricmini (Oct 21, 2008)

Just a quick "heads-up"

Most digital voltmeters (like the one in your photos) have a very high input impedance,
so if you just check for leakage to the controller's casing with the meter on it's own, you can get misleading results!
The meter can read voltage, even if the actual leakage is tiny (microamperes)

Try the check again, but this time with a small load
(put a resistor, say 10k ohm in parallel with the multimeter)

But, there shouldn't be much leakage between the case and ANY of the other terminals. 
It's a bad thing to have any connection between the car chassis (and the controller casing) and any part of your traction pack.
It's also a bad idea to have ANY of the high-power electrical parts inside the cabin - this includes the controller! 
If it goes up in smoke, as well as being a shock hazard, you also can't see to drive because of the smoke...

The fact that you felt something when touching it is BAD, this tells me there is significant leakage current. 
To really check this, you could use a proper insulation tester (but get advice first, typical electrician's insulation testers put 500V dc across the insulation they are testing!).
You should get at least 2 Meg ohms, more likely it should be > 10 Mohm. Anything less indicates an insulation fault.


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## Yabert (Feb 7, 2010)

Well.... it seem I did a reading error about the 24-25k ohm(one digit off)!

A new test give me 250k ohm and Kelly answer me than this value is perfectly normal....

But I try some test with a 120v 25w light. It don't come on when I connect the casing on one therminal and the B- on the other, but I can see few little spark during the connection.


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## Yabert (Feb 7, 2010)

Hi all.

More advanced in the project, so more trouble happen.

I have try to recharge a 8S string yesterday with my temporary charger and some strange thing happen. My goal is charging my complete pack (48s) in six step. I did similare charging last year with my motorcycle battery pack (charging 26s in three step).
To try to resolve the problem, I have try to charge a single cell (3.2v 80Ah) with my Icharger 1010B+ (see picture). And the same strange thing happened. 

I try to explain to you. 
All the cells was at 3.29v and when I start the charger the cell who is connect to the charger go fast at 3.6v and the two cells on both side drop around 3.18v. All the other cells resting at 3.29v....
I tried to recharge the first cell and it work. But the second, third, and other cells can't be charge without causing the drop in voltage of both cells on each side.
If I charge the cell #4, the cells #3 and 5 droping at 3.18v and the cells # 1-2-6-7-8 .....-48 resting at 3.29v.

To try to resolve my problem one more time, I charge my 12v headway battery pack (4s 3p) with the charger and all work correctly. Any of the four cells can be charge without causing a drop voltage from the other cells.

I miss something?
My wirings are bad?
It's a magical electrical bug????

Some help will be appreciate.
Thanks


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## dimitri (May 16, 2008)

If you have sensing wires shared between adjacent cells and you are charging one cell while measuring voltage on adjacent 2 cells, you will have skewed voltage reading due to voltage drop on the shared wire.

Hope this comes out as intended: w - wire , c - cell.

w1-c1-w2-c2-w3-c3-w4

If charger is attached to w2 and w3 to charge c2 and there is certain amount of Amps flowing thru w2 and w3 as a result, then voltmeter attached to w1 and w2 will be a sum of c1 voltage plus voltage drop on w2 due to wire resistance and current flowing thru it.

Same for voltmeter on w3 and w4, but voltage drop will be positive or negative on either side due to charge current direction, so voltage reading on either side will be too low or too high.

Hope this makes sense. There is no problem, you just can't trust voltage reading on adjacent cells while charging the one in the middle. Stop charging first, then measure voltages.


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## dimitri (May 16, 2008)

Actually, I have to correct my statement above, due to polarity of adjacent cells relative to the one in the middle, voltage drop on the wire will be subtracted from cell voltages on BOTH sides, which matches with your description, i.e. both adjacent cells will show lower voltage while charge current is flowing thru shared wires.

So, in your case you have 0.11V drop on shared wires and if you know the charge current at that time you can figure out wire resistance using Ohm's law.


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## Yabert (Feb 7, 2010)

Wow! Many thanks Dimitri...., but the mecanical guy in me understand only 75% of what you write.

That seem a complexe case. If I understand correctly it's a "magical electrical bug".....

About the connection, you are right, it's like that: w1-c1-w2-c2-w3-c3-w4..... W2 connect the positive terminal of C1 through C2 negative terminal.
I think this problem don't happen with my motorcycle because I used two balance wires for each separate Icharger. That make sense?

When I charge a 8s string (c1 to c8), it's like if the c9 drop at 2.9v. Same thing when I have try to charge c2 to c9, c1 and c10 seem drop in voltage.

Can I charge all my pack with confident? What type of test I can do to be sure than no problem will happen. Discharge one cell will be a real problem if I can't recharge it.


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## dimitri (May 16, 2008)

Yabert said:


> Can I charge all my pack with confident? What type of test I can do to be sure than no problem will happen. Discharge one cell will be a real problem if I can't recharge it.


This is very difficult question to answer. As you might know I am proponent of automated battery management systems, because I don't like spending my life in the garage with voltmeter, but your goals might be different. 

For instance, I don't get why you want to charge your pack in segments rather than all at once. I also don't like when sensing wires are used for charging, unless they are thick enough to handle the current with little voltage drop.

I don't recall if you shared your plans for those sensing wires and how you plan to manage your cells. I would charge the pack all at once using same power connections which power the car and only use sensing wires for voltage measurements.


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## Yabert (Feb 7, 2010)

Hi dimitri

As you know, this charging systems is temporairy.
Since a year now, I plan to use 3 mini bms board and one 1500w charger.

But right now, my charger is broken and as you know, I don't purshase the 3 mini bms board..... But I test the car, so I need to charge it.

I charge at 7.5A in 18Awg wire... So I will need around 40 hours to do a full charge....


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## dimitri (May 16, 2008)

As long as the wire doesn't overheat while charging, you should be fine. Don't measure voltages on adjacent cells while charging, so skewed reading doesn't alarm you. If the cell is not being charged, who cares what its voltage is, focus on the ones you are actually charging. To measure cell voltages on edge cells ( i.e. first and last cells in the charged group ), stop the charger, then measure voltage. The idea is not to measure voltages using same wires used for charging. 
For example you can still measure voltages on middle cells since their wires are not carrying charge current, but you can't measure edge cells while charging.

Now you also have to correct imbalance you created when you charged one single group of cells while trying to chase "electric gremlins" 

Hope this makes sense


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## Yabert (Feb 7, 2010)

Well, many thanks!

I will try this tonight. I hope than the Icharger will no be blinded/trouble by the skewed voltage.


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## dimitri (May 16, 2008)

Yabert said:


> Well, many thanks!
> 
> I will try this tonight. I hope than the Icharger will no be blinded/trouble by the skewed voltage.


Voltage is only noticeably skewed when looking at individual cells, but when charging a group of 8 cells, 0.22V difference is not that important. Also, voltage drop is only present at high current in CC mode, as charger reaches CV voltage and drops the current, voltage drop on the wire will disappear, so final voltage will be what you expect it to be, based on charger's configuration. Make sure not to overcharge your individual cell groups since you aren't controlling end of charge. Can you control your temporary charger's top voltage?


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## rwaudio (May 22, 2008)

Are you using the balance wires to charge or are you just charging with the main +/- wires and setting the number of cells?

That looks like it would charge 12 cells at a time (non balanced) for LiFePO4 if I'm looking at the correct charger. You could then charge your pack in 4 sections.

I bought a few very cheap CC/CV power supplies, I have modified them and added trim pots to them so that I can adjust the voltage and current, I will be using them to initially charge groups of cells. It might even be a good option for when I have to plug into a shared power outlet and can't hog the whole 15A.

They seem to have vanished from Ebay, but I bought a few of these.
http://www.ebay.com/itm/270484602718?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_3996wt_1163
I can configure each one as a 12-15 Cell 4.5A CC/CV charger.


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## electricmini (Oct 21, 2008)

Hmmm.. looking at the photos of all the sensing wires and the pack, I can't see any fuses for the wires!

I hope you have put a suitable DC-rated fuse in EVERY wire...
Otherwise if the wires get damaged/cut/squashed, you WILL have a fire

(this isn't intended as a slam, just a friends warning. I'm very impressed with the work you've put into this car!)


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## Yabert (Feb 7, 2010)

Hey! Dimitri... you were right!

I tried to recharge cells 9 to 16 for around 15 mins and like before the voltage drop for the cells 8 and 17. But when I close the charger, those cells come back instantly at 3.29v.
So, I tried a charge for all the night and this morning the result was the same. Both cells come back instantly at 3.29v

But 7-8h of charge give only 26Ah to the cells. In fact the Icharger 1010B+ don't like this voltage skewed and it seem limit the amps of charge at 5A or less.
As you can see in picture, the first and the last cell connect to the Icharger go up fast at 3.60v.

Also, you can see than I completed all the connection without any spark fire. Great news....
I don't have fuse... It's probably not the best idea, but the pack isn't accessible to change a fuse.

Now with this board, I will monitor all the cells and I can charge any cell individually.

Hey! Rw, I effectively charge by the 18 Awg balance wires.
About the 12s capability of the Icharger, considered then I have too much fear to try this with my pack. I lived some bad experiment with a 12v battery (4S of headway) and I'm not really interested to try this with my 7000$ and 100h of work battery pack!!!

Well, conclusion: I will need a good charging systems soon!


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## dimitri (May 16, 2008)

Yabert said:


> But 7-8h of charge give only 26Ah to the cells. In fact the Icharger 1010B+ don't like this voltage skewed and it seem limit the amps of charge at 5A or less.
> As you can see in picture, the first and the last cell connect to the Icharger go up fast at 3.60v.


I think its for the best that you are limited to 5A. You would not want too much current going thru those thin wires.

Also, cells don't actually jump in voltage, cells stay where they are. Voltage jump is due to drop on the wire, it has no effect on cells voltage. If you were to measure at cell's terminals you would see real voltage.

Since this is all temporary setup, I think you are OK for now.


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## Yabert (Feb 7, 2010)

Nice update from the week end test...

After four days of charging... with my 300w charger (running at 150w), I was ready to try another road test with the Smart.
I pick up a friend and a laptop to adjust the throttle position. It was interresting to feel the difference between two "enter".

After we verified than the motor amps and the controller setting were the same and we take a small road to go try the first high speed test.

Result: I can easely reach 100 km/h (62 mph) in third gear. I have never see the speedometer grow up so fast and without any interuption between 0 to 100 km/h.
After, we stop the car to put the transmission in fourth gear (no shifting cable right now).
We restart and put the throttle to the floor.... we reaches 125 km / h (78 mph) without any problem!

The most beautiful thing ..... All this was done with the controller set at half power!!. I'm very happy.


More good news now:

-The KDHD controller doesn't seem overheat even I don't take the time to put fan on it. (the design for the fan is done, I'm waiting for the material). It seem work properly, but I will take no chance and I will put a fan on it this week.

-I have monitored 8 cells during the test with a CellLog 8M and all the cells react perfectly. They stay at a close voltage from each other at low and high amps (< 4C).


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## leonheart (Mar 2, 2011)

I'm really happy for you, your idea for this car is...smart 
I think it could be very fast in the traffic. An efficient vehicle for everyday, 
Good work 

EDIT: I hope you'll post some videos onboard or some hang out, with the controller setted at max power


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## Duncan (Dec 8, 2008)

Hi Yabert

I am using the Headway 16Ah cells like yours, mine will be in one layer but sitting vertically - 
Yours are very close together, if you had the choice would you move them farther apart?

Do the middle ones get hotter? 

Just about to cut "metal" - 

Duncan


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## Woodsmith (Jun 5, 2008)

Yabert said:


> Result: I can easely reach 100 km/h (62 mph) in third gear. I have never see the speedometer grow up so fast and without any interuption between 0 to 100 km/h.
> After, we stop the car to put the transmission in fourth gear (no shifting cable right now).
> We restart and put the throttle to the floor.... we reaches 125 km / h (78 mph) without any problem!
> 
> The most beautiful thing ..... All this was done with the controller set at half power!!. I'm very happy.


Excellent results! 

How was the acceleration in forth and what does your car weigh now?


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## Yabert (Feb 7, 2010)

Duncan said:


> I am using the Headway 16Ah cells like yours, mine will be in one layer but sitting vertically


Hi Duncan

In fact, if I base my comment on the Headway spec sheet, the 40160S cells have 25% higher internal impedance compare to 38120S. So, they will heating faster.... Or maybe can you help me to discover the real impedance of the 40160S (<5mohm?? <8mohm??). It's a mistery for me!




> Yours are very close together, if you had the choice would you move them farther apart? Do the middle ones get hotter?


Close yes! 2mm between each cells at the closer space and 8-10mm at the largest space, but the first test seem good because I discharge the cells at around 0.5C at city speed and I recorded 0.8C at 80 km/h (50 mph). So I hope than the cells don't generate a lot of heat at this small discharge rate.

Really hard acceleration will be for few sec. only and I have pre-build holes for fan in the battery casing. Just in case if highway speed or too much hard acceleration overheat the middle cells.

In fact, if I had the choise, I will probably go with Calb 70Ah....


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## Yabert (Feb 7, 2010)

Woodsmith said:


> How was the acceleration in forth and what does your car weigh now?


Hi Wood

Hummm! I can only said than the acceleration in fourth gear are ''correct'' at this moment because I don't recorded any time number. I will record those numbers in the next road test. 
And remember it's at only 500A. I imagine than at 800-1000A the acceleration at this ''high'' ratio will be more than correct.

Few number to help you: Tires 175-55-R15 give 22.58 inch circumference, trans ratio in fourth = 3.58. 

An estimate about the car weight give me a result around 800-850Kg (1760-1870 lbs), but I will scale the car soon. I'm also realy interested to know the final weight.


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## gor (Nov 25, 2009)

hi, Yabert
tranny looks prety compact - what does it weight? 
what are the ratios? (too many diff kinds of 02j online) 
-------
http://www.diyelectriccar.com/forums/showpost.php?p=235100&postcount=57
and post63


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## drgrieve (Apr 14, 2011)

Yabert said:


> Or maybe can you help me to discover the real impedance of the 40160S (<5mohm?? <8mohm??). It's a mistery for me!


You can determine the resistance of your pack by taking two voltage readings at different amp loadings.

For example if @ 100 amps the voltage per series cell was 3.2V and @ 200 amps it was 3.1V then the resistance is .1 / 100 = 1 milliohm.

If you had 5 cells in parallel then per cell it's 5 milliohms.

You can do the same with an individual cell, but personally I'm more interested in the performance of the pack.


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## Yabert (Feb 7, 2010)

Hi Gor

The transmission is currently a Volkswagen 02A with the code ATA. The weight is 75-80 lbs.

I have start the project with the 02J from a VR6, but I have buy the 02A because the the flange isn't the same (V6 vs L4) and it was easiest to insert in the Smart.


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## Yabert (Feb 7, 2010)

drgrieve said:


> You can determine the resistance of your pack by taking two voltage readings at different amp loadings.


Thanks Dr, I know that.

I have test many of my 38120S cells.

The mistery for me is the real impedance of the Headway 40160S!!!!
5 mohm from the Headway spec sheet and 8 mohm from some US base resellers.

In the the two case, the power capability of the 40160S seem worst than some prismatic cells if you forget the cooling capacity and just watch the voltage sag...


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## drgrieve (Apr 14, 2011)

Yabert said:


> I got the cells!
> 
> So 1000A / 8 = 125A
> 125A x 0.0035 mΩ = 0.4375
> ...


Hi Yabert

I was wondering how close you got to this in your completed pack? Are you able to determine your voltage sag under a certain load while driving?

This would be helpful to me, I'm looking at getting the same cells and wondering on voltage sag on a completed pack.

I'm also interested in the resistance of a completed pack using the 16ah cells. If I find out I'll let you know.

Thanks


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## patrickza (Dec 28, 2009)

drgrieve said:


> Hi Yabert
> 
> I was wondering how close you got to this in your completed pack? Are you able to determine your voltage sag under a certain load while driving?
> 
> ...


Well done so far. Your mechanical work is really something to be proud of. I'm also curious about the difference between the 38120 and 40160 cells. I would have thought they should give the same performance as they were using the same chemistry, but that may be wrong.


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## Yabert (Feb 7, 2010)

patrickza said:


> I'm also curious about the difference between the 38120 and 40160 cells. I would have thought they should give the same performance as they were using the same chemistry, but that may be wrong.


Hi

Both cells are lifepo4, but not all the lifepo4 cells have the same power capability or same energy density.

From the Headway spec sheet, the 38120S have a better power capability compare to the 40160S, but not a better power density.

Exemple for a 12.3 Kwh pack (48s (154v) 80Ah):

38120S: 48s 8p = 384 cells (279 lbs). At 1000A voltage drop at 117.6v (0.006 mohm) = 117 Kw = 2.37 Kw / lbs
40160S: 48s 5p = 240 cells (264 lbs). At 1000A voltage drop at 105.6v (0.005 mohm) = 105 Kw = 2.5 Kw / lbs


But all this is theorical and like drgrieve said, a complete pack can have an higher impedance.
And some cells can have a smaller impedance than other.


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## Yabert (Feb 7, 2010)

I have post some spec of the headway cells (40160S and 38120HP) on the thread bellow (post #23):

http://www.diyelectriccar.com/forums/showthread.php/cell-comparisons-please-contribute-62326p3.html


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## Yabert (Feb 7, 2010)

Big new!

How big??... Well, 33 lbs and around 870 cubic inch.

I will put this Soliton 1 in my car this week...


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## rwaudio (May 22, 2008)

Very nice controller!! I'm sure you will enjoy the Soliton1. I see an EV Display as well, did you buy it directly from Dimitri? I have to order one this week. Where are you going to mount the minibms boards? Did you get your Elcon fixed yet?

Are you going with water cooling or just start with "air" on the Soliton?? I know you kind of maxed out the battery room but do you have any plans to up the voltage to take advantage of what the Soliton can handle?

I finally drove my car to work last week, only 32S3P but it was an awesome drive and I'm very happy with the 944/11hv/Soliton1!


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## Yabert (Feb 7, 2010)

Hi RW

Yes, all come from the Dimitri store.
About the Elcon, I ordered a new one without paying the shipping cost and I hope I will be able to repair the old one soon.

I will start to run the Soliton with air cool. After all, my car will need only 10-25kw to move most of the time. I will watch the Soliton temperature when I will play hard with the car.

About the voltage, if I have to restart my pack, I would like to build a 64s 6p pack to obtain an higher voltage under high load (more power). But right now, I'm more interrested to drive my car with 100-120 availiable hp instead of take one or two more month and some money to rebuild my 48s 8p pack. Maybe next summer!

It's good to hear than your car is drivable. I think you are in a situation like me... some video of the car will be need soon!


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## Yabert (Feb 7, 2010)

BIG BIG NEW!

My motor is destroy!

http://www.diyelectriccar.com/forum...oliton1-customer-support-thread-39252p13.html


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## dimitri (May 16, 2008)

Have you assessed motor damage yet? Any pictures?


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## rwaudio (May 22, 2008)

Yabert said:


> BIG BIG NEW!
> 
> My motor is destroy!
> 
> http://www.diyelectriccar.com/forum...oliton1-customer-support-thread-39252p13.html


Very crappy, sorry to hear about the unlucky event. Your motor was so nicely cleaned up and with the custom end plate. Do you think you will be able to find a similar motor? It's an oversite by the guys at evnetics that this was able to happen in the first place, but I hope the next software revision will make that a harmless icon to press. An OEM might gloss over that incident as bad luck but not fix it unless it was happening to everyone. (Or you would never get the info to the right person, with Evnetics now the right people know.)


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## Yabert (Feb 7, 2010)

A french expression said: Une image vaut milles mots!

The copper bars goes out of her slot and go hit the stator part......
I'm so f...ing sad!


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## Yabert (Feb 7, 2010)

I forgot one thing....

I can't currently disassembled the armature from the stator because some armature bars seem welded on the stator!
I can see an air gap between two stator core and the armature, but no gap between the two others and the armature.


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## Woodsmith (Jun 5, 2008)

Oh dear!

Can you remove the drive end coupling and drive end cap and then undo the field pole bolts and slide the whole lot out of the barrel?

That might then give you a chance to part the fields from the armature to assess how badly it has failed.

I am sorry to have read about your motor, I came very close to doing likewise with my tractor when I first connected the controller. I didn't know that I had my throttle pot reversed and started on full throttle. The controller flashed a fault light and then fired up the motor on full power. Fortunately I was testing on 36v and was only holding a jump cable to one of the battery terminals as an emergency stop and was able to cut power when it made me jump.


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## Yabert (Feb 7, 2010)

Well, more than a week since my motor was blow and the news aren't good. It seem than my motor is scrap because the armature bars was going out from her slot and too much copper is teared on the side.


But I try to continue my conversion. This week, I installed my stainless steel water heater and his element (120v 1500w). Theorically, that will give 2000w of heat for my small cabin. I hope that will be enough.

Also, I finally connect the three Mini BMS board to my 48 cells. It's not really fun to play with 49 potentially dangerous tiny wires. Hopefully, no bad luck happen and I will ready to fully charge my pack.

So, the next step will be to fix my new Mean Well SP-320 power supply (300w, 13.5v and 22A for less than 100$) and build a small 12v 10Ah battery with Headway cells.......... Oh! and of course, find and integrated a new motor to my drivetrain..


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## rwaudio (May 22, 2008)

The heater looks cool, did you make it or buy it?
What type of control are you going to use? 

Are you going to leave the dc/dc on all the time or have it on a switch? The headways should make a good 12v battery though, when I drove my car to work, I had the stock lead acid in parallel with a 20ah pack of headways and I had a rock solid 13v the whole time with headlights on etc. and that was without a dc/dc converter.

Good luck with the hunt for a new motor, although I'm sure you put a lot of work into integrating the motor, I'm sure the $$ wasn't as bad as a warp 11 or 11hv.


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## Yabert (Feb 7, 2010)

rwaudio said:


> The heater looks cool, did you make it or buy it?
> What type of control are you going to use?


I have make the heating exchanger. Full stainless steel construction with a 120v 1500w element. Total cost : 20$. When do you order your's?..

The element need 16A at 156v for 2500w of heat. 
I does a small test with water starting at 10°C and 10 second later the half liter of water was hot. It's an impressive result for me. I'm happy to know than I will be able to have a good amount of heat in my car after 20-30 sec because the full circuit of water contain only around a liter.

Hum! I was thinking use a simple water heater thermostat (like picture), but I juste realize than this kind of part can't maybe work with dc current.
That can work or no?


About the DC-DC, I think leave it on all the time. Maybe I will add a switch to disconnect the 12v from the main pack in some occasion.


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## Woodsmith (Jun 5, 2008)

Could you use the thermostat to trigger a 12vdc relay that can handle the high dc voltage and current?


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## rwaudio (May 22, 2008)

Yabert said:


> I have make the heating exchanger. Full stainless steel construction with a 120v 1500w element. Total cost : 20$. When do you order your's?..
> 
> The element need 16A at 156v for 2500w of heat.
> I does a small test with water starting at 10°C and 10 second later the half liter of water was hot. It's an impressive result for me. I'm happy to know than I will be able to have a good amount of heat in my car after 20-30 sec because the full circuit of water contain only around a liter.
> ...


I've heard some people say that the thermostats in heaters won't work off of DC, I'm using a pair of 1500W Kats water heaters and they have built in thermostats but was warned they won't work on DC. The Porsche has an analog automatic climate control system so it uses temp sensors and vacuum to adjust the coolant flow to the heater core to maintain your selected temperature (numbers on a dial). I will have a microswitch on the vacuum controlled valve, so that when it fully closes it will turn off the heater and pump. As soon as it opens again even just part way it will turn on the heater/pump and hopefully work fairly naturally. The fan is always on if the car is running so there is no worry of it turning off completely and can be turned up for the desired airflow.

I do like your heater block better, mine are round and a bit tricky to mount. I'm thinking of putting them inside an insulated box within the motor compartment though, but haven't actually done it yet.

With the mean well, and some slight modifications you could create a 2 stage voltage setting, IE 14.x volts when the car is running and 13.2-13.6 on all the time when the car is "off". That way you have good voltage for nice bright lights etc when running but don't overcharge your headways at the same time keeping them topped up.

I'm not sure if I'm going to just use the mean well or complimentary it with a few dc/dc converters, I'd be interested in hearing how well it works if you get there first.


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## gor (Nov 25, 2009)

Yabert said:


> Well, more than a week since my motor was blow and the news aren't good. It seem than my motor is scrap because the armature bars was going out from her slot and too much copper is teared on the side.
> 
> 
> But I try to continue my conversion. This week, I installed my stainless steel water heater and his element (120v 1500w). Theorically, that will give 2000w of heat for my small cabin. I hope that will be enough.
> ...


Yabert, glad you back, man! 
i would have three heart attack, two successful suicide attacks and one (but long) hangover; 
and you back on track - stronger and better than ever!

till we'll find bigger and better motor - do you have pics of your battery bank from underneath - does it comes in-and-out like on pict?


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## Yabert (Feb 7, 2010)

More pics of the motor carnage!

I send my motor has a local motor repair shop. They has disassembled this one to see if it can be rebuild.
Conclusion, too much money to rewind the armature and the stators pole was bending during the destruction.

Where I will find a 15 inchs long motor able to produce 250 lbs-ft of torque at 1000A???...... for 250$ (hum! where is the stupid smiley with the river of weep?)


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## Yabert (Feb 7, 2010)

gor said:


> do you have pics of your battery bank from underneath - does it comes in-and-out like on pict?


No. Yes. 
A complete picture of my pack from under the car will be very similare at your second pic. Except than my pack is a bit larger, they don't have a large gap between the car frame and the pack. Also, the support of the pack is under this one.


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## major (Apr 4, 2008)

You know Yab? I don't think your armature was ever properly treated at the motor factory. There is no evidence from your photos of a varnish or resin coating or impregnation in my opinion. I was bothered by the failure mode. It is usually the case where the ends of the armature coils balloon or mushroom out from overspeed. You rarely see coils exit the middle of the slots like that.

You say it was a Crown motor and thought maybe GE made it. I can't tell. It does not look like GE construction to me and I don't think Crown makes motors in that size. It could be a private labeled build from elsewhere. And it may have had suitable construction for the intended forklift application. This is one of the pitfalls of repurposing such motors. I have no doubt that during your mistaken pushing of the wrong button that this motor did see high RPM, but because the comm and opposite end coil knuckles are still intact, I think it was not super high RPM. 

And if in fact the armature did not have the proper varnish treatment, it likely would have developed other electric insulation issues soon in its use.

Bad luck all around, dude. 

For the lack of a suitable replacement motor, you might write a letter to Crown and inquire as to the manufacturer of this motor. Then see if they would be willing to rebuild it or sell you a new set of coils. If the coils came out that easily, it would be possible to strip the core and rewind. The coil forming is the tough part for local motor rebuilders. I'd get a second, third opinion on the rebuild.

major




Yabert said:


>


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## gor (Nov 25, 2009)

Yabert said:


> More pics of the motor carnage!
> 
> I send my motor has a local motor repair shop. They has disassembled this one to see if it can be rebuild.
> Conclusion, too much money to rewind the armature and the stators pole was bending during the destruction.
> ...


250f-lbs/250$? ... some old warp9 would be too big - 277f-lb, but taken from wheels on dyno after losses - at the motor output it would exceed your power requirements even more


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## EVfun (Mar 14, 2010)

A NetGain ImPulse 9 is 15.07 inches long to the end of the motors shaft if cut the shaft to make it single ended. It should make around 180-200 ft/lb. of torque at 1000 amps. The field poles where moved slightly off center of the armature to reduce the torque per amp (increase the rpm per volt) because it was designed as a higher peak power replacement for an ADC 8 inch motor. This shift of the field coils was discovered in the making of the White Zombie siamese 9 motor (2 Impulse 9's on one shaft) and they where moved back for that high voltage application.


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## Yabert (Feb 7, 2010)

Thanks Major for the inputs... I don't know anything about the factory quality of my motor. I added a good amount of Fiberglass Cloth Insulating Tape on the end of the armature, that can probably help to save the commutator.

In fact, like you can see, the bars going out of her slot because the retaining tape in the center was broken.
Don't you thinks than an instant 160v with 500 availiable amps was enough to push this motor at 1X XXX rpm in few sec?


Thanks EVfun! I know about the impulse 9. I have read something similar somewhere. I thinks it can be a good motor for my application. I have tried to integrated the Impulse motor inside my Cad drawing. It can fit if I modify some parts and build some others, but I fear three things about this short motor:

1-His 1h rated torque of only 24 lbs-ft!! How fast it will overheat if I run it at 300-350A (too low rpm)?

2-His efficiency when you dump 1000A and 120v at his therminals! What will be his peak power with my current battery pack? Something like 120v (after sag) x 1000A x 0.75 = 90 Kw or is it more like 120v x 1000A x 0.65 = 78 Kw???

3-With my ''big'' motor I can performed an impressive 0-100 km/h in third gear. With the Impulse, I will probably need to start the 0-100 in second gear and shift in third gear at 4500-5000 rpm.

Oh! I forgot a fourth thing..... his price!


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## piotrsko (Dec 9, 2007)

looks like a 10" 144 kostov might make that torque, but I don't know for how long. I have also seen some "old style" pretty cheap and they are short enough.


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## rwaudio (May 22, 2008)

gottdi said:


> http://www.mwands.com/index.php?main_page=index&cPath=40
> 
> DC Water Heater elements. 24 volt 600 watt. Watch the vid too. Do not go to ebay and buy the BS AC elements that are being sold as DC.


There is no difference between a resistive AC or DC heater, the impedance/resistance of the element determines what voltage it will run at. I can't imagine a 600 watt heater being very useful in an EV, and at these low voltages you would need lots of elements (expensive/big/complicated) plus the added complexity of having thousands of watts at 12 or 24v. (big/heavy/expensive dc/dc converter)

The one thing going for these elements, it appears that the build quality is above average.

Although the version with a thermostat is interesting and not common to DC, it's only 250 watts, so even less useful in an EV.

I'm guessing that the element that Yabert used was one of the cheap 1500 watt 120v AC unit's and it will work just fine and at high power off of his DC pack. The only risk in over voltaging a heating element is the risk of it overheating and burning out (becoming an open circuit and refusing to dish out any more heat).

The guy in the video doesn't actually say anything wrong, (that I noticed) but what he is using as his argument is like saying you can't apply more than 36v to a forklift motor because it has 36v stamped on the name plate. Physics and ohms law still apply outside whatever the manufacturer stamped on it, and if you don't push those limits too far it will work just fine in other applications and voltages and RPM's. I think he should be pushing the idea of the DC thermostat, or the build quality instead of AC vs DC, it's like saying there are AC resistors and DC resistors and you can't mix them up, resistors are ALL THE SAME (in that respect).


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## JRP3 (Mar 7, 2008)

rwaudio said:


> With the mean well, and some slight modifications you could create a 2 stage voltage setting, IE 14.x volts when the car is running and 13.2-13.6 on all the time when the car is "off". That way you have good voltage for nice bright lights etc when running but don't overcharge your headways at the same time keeping them topped up.


How would you set this up? Set the Meanwell for 14.x and use a small DC/DC to step it down to the battery? I'm using a Meanwell but have it set at 13.x to save the AGM battery but it's a little low for running accessories.


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## rwaudio (May 22, 2008)

JRP3 said:


> How would you set this up? Set the Meanwell for 14.x and use a small DC/DC to step it down to the battery? I'm using a Meanwell but have it set at 13.x to save the AGM battery but it's a little low for running accessories.


The mean wells have a voltage trim pot, set for 14.x and measure the resistance. Set for 13.x and measure the resistance again, then use one of the many Internet parallel resistance calculators to find what resistance you would need to parallel with the pot to get the 2nd resistance, use an NC or NO relay tied to the ignition to switch in the 2nd resistor at the proper time ( ignition on/ignition off) just wire it so the ignition off state is relay off and lower voltage. I will probably be doing this with mine so I can detail the process if helpful to others.


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## JRP3 (Mar 7, 2008)

Cool, I'll let you experiment and work out any bugs, then I'll copy it


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## rwaudio (May 22, 2008)

JRP3 said:


> Cool, I'll let you experiment and work out any bugs, then I'll copy it


I won't hijack Yaberts thread so the details are here:
http://www.diyelectriccar.com/forums/showthread.php?p=269257&posted=1#post269257


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## Yabert (Feb 7, 2010)

Hi

Because I have a bit of time to waste (No motor since five weeks now), I show you some past modifications.

You can see the small beast without hood... Well, without his front cover!
Under this front cover there are the heating systems. Stainless steel tank and the 1500w 120v element without the insulating, the small auxiliary pump from a old Mercedes Benz and the EV200 contactor.
I will also put the charger at this place just over the steering rack.

Also, you think pass a 2/0 cable inside the EV display current sensor..... good luck!

And finally, you can see the EV display close to the two others gauge under the steering wheel.
It show 161v and 16.6 because the heater is on. Over 2500w of heat!
I have charge and discharge the battery pack at 5% DOD by warming my car and the mini BMS board seem work properly. It stop the charger when the first cell hit 3.6v, but at this time only 15-20 cells from 48 are in shunting operation. So my battery pack isn't perfectly balanced.


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## JRP3 (Mar 7, 2008)

I never thought 2/0 would fit through the EV Display hall sensor. Must have been quite a struggle.


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## Yabert (Feb 7, 2010)

Well, theoretically the area of a 2/0 wire is around 0.138 square inch and the EV display current sensor have an area of around 0.180 square inch..... but in reality, it really tight!

Otherwise, I think an 1/0 wire can pass without too much problem.


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## Arlo (Dec 27, 2009)

I cant wait to see how this works out for you.


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## Yabert (Feb 7, 2010)

I taken a bit of time to program the Soliton 1 outside of the car. I have test my throttle and the tach sensor. The high rev limiter work properly and I have idling my motor just to try.
Thanks to the EVnetics guys, the input range of 9v to 342v is awesome. Programming on 12v is a great advantage (so easy) and really secure! (12v only = low rpm for most motor)


Oh! more news.... The small Impulse 9 is in the mail!
More news soon.


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## madmike8 (Jun 16, 2011)

I'm glad you have a new motor on the way... and the controller is setup. I like your build.


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## gor (Nov 25, 2009)

hi, Yan - glad you doing well
tell a bit more - why small and why impuls9?


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## StanSimmons (Sep 3, 2011)

gor said:


> hi, Yan - glad you doing well
> tell a bit more - why small and why impuls9?


I think a WarP11 would drag on the ground.


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## gor (Nov 25, 2009)

Yan, no luck with good-old 11'' forklift beast? cheap and furious, and if it fries under 1k amps - at least it's not 2k $ brand new gone
----


StanSimmons said:


> I think a WarP11 would drag on the ground.


there are always a room for improvement - can't you see on the pict., how plenty of room to the ground still could be used? (and i see the room for one more)


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## Yabert (Feb 7, 2010)

gor said:


> tell a bit more - why small and why impuls9?


All is a question of length!
My Smart has a really small ass and most motors was imposible to fit in (warp 9 and 11, Kostov 10 and 11).
And about the Impulse 9 choose, I think it will be better to entirely exploited my current set up who is low voltage and high amps (125v after sag and 1000A). 

I will dump 100-125 Kw at motor terminals and I hope it will efficiently convert this power in 100-125 hp.... I hope!
In comparison, the Kostov motors seem have a really bad efficiency at over 600-700A.



> I think a WarP11 would drag on the ground.


No! In fact, my last motor had the same diameter than a Warp 11... only shorter.


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## Yabert (Feb 7, 2010)

Hi all

So, almost 3 months (incredibly long) since my last Smart Fortwo ride, I'm today able to try the car at town speed to test my new Impulse 9 motor.
Settings were at 400A motor and 200A battery... All seemed good in my 10-15 km trip.
Thanks to Seb from EVnetics for all the support about motors.

More test soon.

*But now, motors comparison!*

Compare to my last 11" motor (the green one), the Impulse 9 have only:

-75% of the copper area on the armature bars.
-90% of the brush area.

So, if all is smaller, how I can expect have the same efficiency under high load (120 Kw at terminals) compared to my last 11" motor?
Or maybe I miss something? Comment?


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## Yabert (Feb 7, 2010)

Last update.

Current controller setting: 
-Motor 750A
-Battery 400A
-160v unload

Acceleration are quick in second and third gear, but not as much crazy I would liked...
But there are three good explanation about that: 

1- The limited torque of the Impulse 9 compared to my 11'' green motor..
2- At least 25% more torque staying available (1000A)
3- Battery really don't like freezing temperature there have here. The voltage sag is bad!

I set the Soliton to minimum battery voltage under load at 135v so my current peak power is around 45-50 Kw compared at the theorical value of 55-60 Kw (400A limited). 

Well, no high performance Smart Fortwo until spring... exept if my small 126w heating cable can be enough to heat the cells to 15-20°C (60-70°F)!!. Probably impossible starting from 0 to -10° C.


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## EVfun (Mar 14, 2010)

No matter how to apply 60 horsepower in a passenger car it won't be described as "crazy."


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## Yabert (Feb 7, 2010)

Well, you are right..., but I more talking about impressive low end torque at low speed (under 56 km/h (35 mph)) instead of high power to accelerate at high speed.

But you know (especially you) 60 hp under 1500-2000 rpm can be impressive in a light car for city speed acceleration!! (Considering than this 60 hp will be maintained at higher rpm).


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## Yabert (Feb 7, 2010)

Nice little update!

Second time I commute to work today. I'm really happy!.
35 Km (22 miles) one way. I charge at work because I'm around 50% Soc when I drive really gentle on backyard road and around 40% Soc when I take highway.

Theorically, that give me 40-50 km range (80% discharge) in this poor winter conditions (-12° C, snow on road, wind, heating).

I can easely maintain 105 km/h (65 mph) and at this time I don't have try over 112 km/h (70 mph).
I will try to take few picture of battery pack and drivetrain from under the car next week because I will go to garage to change tires.


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## Yabert (Feb 7, 2010)

As promised, I took few pics from under the car.
It was the first time I could entirely see most of my work.

We can see:

-Small Impulse 9 motor mostly insert inside the VW transmission bell housing.
-Do you remember my 12.3 Kwh battery pack? (P. 8)

As you can see, dirty and salty winter road here in Quebec have consequence on the car. Rust and dirt is part of the car!
Next step is to close the front of the car, puting back the original plastic cover under the car and complete a proper recharge outlet. 

Oh! And I tried to go fast on a small stretch of highway last week... 125 km/h with limited low battery voltage and limited Amps at -5°C. I'm happy!


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## xsherlock (Mar 1, 2009)

Hi,
Great project, following closely, especially that I have exactly the same Smart (same color and rims) that one day will be electric.

One question, how did you solved the ESP issue? Did you manage to keep orginal ESP working? I have driven my Smart several times with ESP disabled in a winter and that is a death trap, that realy want to go ass first into every corner. I would expect that with electric motor it will be hard to control without ESP.


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## Yabert (Feb 7, 2010)

xsherlock said:


> One question, how did you solved the ESP issue?... I would expect that with electric motor it will be hard to control without ESP.


I don't solved...
The car is a real pain to stay on road during snow storm!
By chance, most of my last car was RWD, so it's more fun to drive. On demande electric torque help a lot.
But isn't anyone who can drive this little go-cart in snowy condition without ESP. 
I take care and I cross finger's. 




A bit more test today: 135 km/h (84 mph) with 350A battery limit, single gearing (0-135 in fourth gear), 2°C and wind...
I can't wait for summer performance!


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## Yabert (Feb 7, 2010)

Few others updates.

I have put the car on http://www.evalbum.com/4155

I finally decide to replace my hot water systems by a ceramic heater (15$ in sale). With this one I have a fairly good amount of heat (2600w) faster than with my water systems. 
By chance, I just need to modify current Smart 12v heater by the 120v 1500w heater and it's done. 

I show you the modified adapter plate need to integrated the Impulse 9 at the place of my 11" motor. You can see RPM sensor.

Also, I tried another speed test with only 350 Amps on battery side..... Next step is out of range...


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## Yabert (Feb 7, 2010)

*2000 miles* of done since the car is drivable (I can't write "finish"..).

Without any problem.... Well, without major problem!
In fact, two problems have occurred:

-I burned the sender board of my EV Display because a bit of rain enter inside the car when I worked on the car (I don't have garage...).
It's stupid, I took the time to put fuse on DC/DC, heater, etc, but I forgot to put fuse on the EV Display.
I was afraid when 158v shorted happen... by chance, the sender board solder has literally explode and stop the the current flow. I needed to buy a new board... and add a fuse!

-The motor brush disappear faster than snow under sun...
A lot of carbon dust appear at the motor output and I thinked it's was strange. So I ask to Netgain and it seem than I have racing brush grade in my motor (H49) and I will need to swap for regular brush (H60 grade).

Exept this, all is fine and I really like drive this small go-kart with only 50Kw peak... after all, it's 40% more peak power than with the original diesel engine.
I go at work each day at -15°C or at +5°C without problem, but the voltage drop at highway speed is relatively important at this low temperature. 

I can't wait summer temperature to set the Soliton at 100-120Kw output..


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## Yabert (Feb 7, 2010)

After 3000 miles and more than two month driving the Smart with a fix ratio (4e gear) most of the time (sometime 2e gear around town), I finally installed the shifter box in the car.
Can you imagine how much usefull it is to engage the reverse!!! Without pushing the car or going out to engage proper gear...

First impression, I'm really suprised how well the transmission changed gears. I can shift this clutchless system in less than a second... good thing for future 1/4 miles race!

Like you can see, I needed to build a custom support for the VW shifter mecanism and the strangest thing, the shifter box is in reverse direction compare to FWD car.... Yes, I push for 2e and 4e gear and I pull for 1e, 3e, 5e and reverse...


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## rwaudio (May 22, 2008)

I'm amazed you went that long without reverse! (or inside accessible reverse anyway).

Do you find much of a performance difference being able to use multiple gears?
How about efficiency?


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## Qer (May 7, 2008)

Yabert said:


> Can you imagine how much usefull it is to engage the reverse!!!


*ROFL*

That made my morning. Thanks. 

And nice conversion. Although you should probably change the label on the car to "Forone". Or are you planning on putting the second seat back too?


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## Yabert (Feb 7, 2010)

rwaudio said:


> Do you find much of a performance difference being able to use multiple gears?
> How about efficiency?


Well, performance don't change at this moment because this small car is peppy in second gear. On this gear, the car reach 0 to 70 Km/h (0-43 mph) and I don't try performance acceleration (0-100 Km/h) at this moment.

The efficiency seem to be the same on different gear in same condition.
After all, the motor don't care to run at 2000, 3000 or 4000 rpm when you put 10-15 Kw at his terminals.

And it' why I think than a direct drive application is perfectly acceptable for a small car with oversize motor and controler. Exactly like I said at the beginning of my project 17 month ago!!

An 11'' motor powered by a 1000-1400A controller can be realy fun in direct drive application considering a limited top speed under 100 mph.



> That made my morning. Thanks.
> And nice conversion. Although you should probably change the label on the car to "Forone". Or are you planning on putting the second seat back too?


I'm happy to create smile...

The second seat is most of the time at his place.
I need this seat to give at friends a ride.... Each time one of those passager said: ''It's crazy, this car is fast, the torque is awesome'' I'm forced to repeat: ''You know, right now the controller under your ass limit the motor power has half of his max power capability....


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## Yabert (Feb 7, 2010)

I took couple of hours to do some maintenance and upgrade this weekend!

I had to change the brush and my RPM sensor won't work correctly, so the easiest way was to take off the entire powertrain from the car.

*Brush:* The racing brush was remove and you can compare with the news ones... After only 5000 Km! The news brush have 5'' cable stupidly long. They protrude out of the motor case. 

*Tach sensor:* The Soliton 1 was able to detect motor RPM to around 3000 rpm, but after this speed, it wasn't able to limit the motor RPM. I had a doubt than the Soliton wasn't the cause and I decided to enlarge the slot detected by the sensor. You can see the difference between both slot on picture. Now my Soliton can limit motor rpm to 5000.

I also show you the powertrain under the ''hood''.

Finally, if you think than my motor is rusty and dirty..... well, you are right, but winter will end soon.


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## Yabert (Feb 7, 2010)

There has a few days of warm weather these days (20°c) and I took the occasion to crank up the Soliton 1 to 100 Kw peak...

The little green beast is alive!!!!..

The power is just awesome and pull a big smile or a cry at any passager... and driver!
My Ev Display show 100 kw and the battery amps are limited to 800A... so, a bit more power stay available!

Some numbers (0-100 km/h) and video to come.

Oh! and I realised yesterday than my speedometer is stoped to 140 km/h when I notice that the car still accelerating strongly and the needle maintain 140...


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## xsherlock (Mar 1, 2009)

Yabert,

Could you please explain how do you use the VW transmision without the clutch?
Can you change gears while driving? or you decide on a gear before you drive away?


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## somanywelps (Jan 25, 2012)

xsherlock said:


> Yabert,
> 
> Could you please explain how do you use the VW transmision without the clutch?
> Can you change gears while driving? or you decide on a gear before you drive away?


Look up clutchless shifting.

The transmission uses the synchros to match the flywheel RPM with the input to the transmission.

In this case, you manually get close and it just does that to the electric motor instead of the flywheel.


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## rwaudio (May 22, 2008)

Yabert said:


> There has a few days of warm weather these days (20°c) and I took the occasion to crank up the Soliton 1 to 100 Kw peak...
> 
> The little green beast is alive!!!!..
> 
> ...


very nice! do you know the final weight?


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## Mark C (Jun 25, 2010)

Congratulations on the cars performance. It's rewarding to see it do so well. 

My sister recently bought a 2009 smart passion and loves it. I had a chance to drive it and found the automated manual in hers to be an odd experience. I'm certain I could easily get used to it. That said, are you using the automated manual transmission like an American market smart has? I don't find any real manual transmission models on the market but I think a smart car would be a great choice for me and the wife. {I've read this thread all the way through before, and come back to it several times and I don't think you have this transmission, but I can't keep myself from asking.}


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## Yabert (Feb 7, 2010)

I tried a 0-100 km/h using only third gear: 8 sec.
Not bad considering 800A battery limited (15-20% power staying available)..... Oh! and a 220 lbs passenger (over 10% of the total weight). Haha!

The acceleration is way more impressive in second gear, but my bad shifting skill at 70 km/h ruin my time (same 8 sec using two speed).
I need practice!



xsherlock said:


> Can you change gears while driving? or you decide on a gear before you drive away?


Before I installed my shifter box, I continously drive in fourth gear. 
Now, I use second or third gear in city and I use third and fourth gear to go on road and on highway... I probably shift gear 2-3 time to go at work.
I push on shifter lever and the synchro in transmission slowed the armature speed and the gear engage.

Mark C, I use a Volkswagen transmission!

I hope know the final weight of the car soon


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## Yabert (Feb 7, 2010)

I forgot some important numbers: 

I record as good than 150 wh/miles at 35 mph and 225 wh/miles at 60 mph.
But I also record as bad than 260 wh/miles at 35 mph and 350 wh/miles at 60 mph in poor condition (winter, wind). The heating wasn't powered at those moments.
Flat ground here!

That represent 6 to 9 Kw to maintain 35 mph and 13 to 21 Kw to maintain 60 mph.
I generally use around 7 Kw at 35 mph and around 14-17 Kw at 60 mph.

But I think than the theorical maximum range of over 70 miles at city speed is distorted because I sometime need 25-30 kw to keep up with crazy petrol users humans! (traffic)


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## Yabert (Feb 7, 2010)

A picture is worth a thousand words!...


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## powerhouse (Apr 1, 2011)

beautiful.


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## rwaudio (May 22, 2008)

Sweet, when do you install the wheelie bar?


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## Woodsmith (Jun 5, 2008)

That's a great photo!


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## Arlo (Dec 27, 2009)

Awesome very very awesome!!!!


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## MalcolmB (Jun 10, 2008)

It's supposed to be a Smart ForTwo people, not a SmartForTwo wheels


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## skooler (Mar 26, 2011)

Back to where you started yabert... On 2 wheels!

wheel stop now. I promise


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## Yabert (Feb 7, 2010)

In fact, if you watch carefully my bike video, you can see than my bike has riding on one wheel!..

Sériously, thanks guys for the good comments.

I was on a scale this morning: 1900 lbs (865 Kg) 
The car weight a bit over than what I have estimated.


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## Yabert (Feb 7, 2010)

Cold weather is come back this week. So, at 0 to 10°C my power is limited.
By waiting a temperature increase, I took some time to assemble some videos from winter ride. http://www.youtube.com/watch?v=PtMzHnZ2ZWE&feature=email&email=comment_received


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## drivin98 (May 9, 2008)

Smart DC is on AutoblogGreen.


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## frodus (Apr 12, 2008)

Just saw the ABG article, nice work Yabert!


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## Yabert (Feb 7, 2010)

Cool! It's a good thing, right? (sorry, I rarely read english news) Nobody ask me anything about this review.
A bit of free publicity for Evnetics and Netgain...

Thanks drivin to share.


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## tido (Sep 20, 2011)

Nice article... I'm thinking of putting all my batteries in the back of my future ev fiero to do a wheelie as well! I guess it's a bad idea.....


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## Yabert (Feb 7, 2010)

Some DC motors from projects.

My destroyed 11'' motor, a big 11'' GE without drive end and with cracked CE (but black and grey CE are compatible), finally my little 6.7'' D&D ES-15-6 (still to sell).


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## Yabert (Feb 7, 2010)

*5000 miles!!*

That represent: 

-An economy of around 1000$ considering current gas price in Québec (based on compact car consummation).
-Literally a ton less of CO2 in the atmosphere (around 1200 Kg to be more specific)
-Some quantity of rubber from tires in the atmosphere and many many EV grin...


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## Yabert (Feb 7, 2010)

First major problem happened after more than 10 000 Km. 
It's not a sad story... The wheel torque in first gear is too much for the driving shaft. Some consequence happening when the tires slip on an irregular pavement...
That took maybe 1 and half sec : The fronts wheels lift in the air, the rear tires start to slip and the front wheels go down, the rear wheels restart to take grip on the pavement and CRACK!

That happened at 12:30pm yesterday and I took a part of the afternoon to repair the drive shaft with a bigger diameter tube to go home around 6:00pm. The two smaller shafts are press fit in the bigger tube and tig welded.
Hope the new custom drive shaft is stronger than the last one!


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## Woodsmith (Jun 5, 2008)

Way to go! 

Looking forward to the next break!
There are similarities between your Smart and my tractor!

Are you going to find stronger shafts for a more permanent solution?


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## MalcolmB (Jun 10, 2008)

That's a concidence. I've just been in the workshop, machining some new drive shafts for the Mini, and I was wondering why I'd not seen any drive shaft failures in electric conversions...

That's a neat fix, but the original drive shaft design looks odd. From your photo it looks like a heavy-wall tube surrounded by a thinner walled tube. The inner tube looks as if it stops a few inches short of the inner CV joint. The fracture seems to have started at the pin through the two tubes. Do you think it's designed as a deliberate weak point? Perhaps Smart guessed that someone might try doing wheelies


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## Yabert (Feb 7, 2010)

MalcolmB said:


> Do you think it's designed as a deliberate weak point? Perhaps Smart guessed that someone might try doing wheelies


Haha, no! In fact, the driving shaft has broken close to where I modified his length last year...http://www.diyelectriccar.com/forums/showpost.php?p=240161&postcount=62
Internal tube + few spot weld wasn't a good idea.



Woodsmith said:


> Are you going to find stronger shafts for a more permanent solution?


Well, no. I think the best solution is to start in second gear (1350 lbs-ft at wheels) and stop to pop a wheelie in first gear when 2400 lbs-ft are apply to the wheels. Well, ''apply'' is relative because 95% of time the tires slip in first gear and the max torque isn't applied. The other 5% of time, the front wheels lift from the ground!..


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## MalcolmB (Jun 10, 2008)

Yabert said:


> Haha, no! In fact, the driving shaft has broken close to where I modified his length last year


Oops, sorry, I didn't mean to insult your workmanship 
In fact with all that torque, it's probably a good idea to have a readily fixable 'fuse' in the drive line.


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## Yabert (Feb 7, 2010)

Important problem occur! After more than 200 recharges with my Elcon 1500w, it decided to die.
I don't know why, I don't know how to don't reproduce this situation and I don't know if I will buy a new Elcon charger.
The second charger is the first one I bought one who had never work.

I'm now forced to buy gas... sad situation!


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## Mad Professor (Dec 18, 2010)

Wow, what on earth happened there?

Did it just go bang, or catch fire?


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## Woodsmith (Jun 5, 2008)

Looks like that melted relay is at the centre of the damage, but there is also soot where the incoming cables terminate.


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## mk4gti (May 6, 2011)

wow, not good ! 

what was the SOC of the batteries after this incident? I assume you were charging?

You seem to have had your share of bad luck !


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## rwaudio (May 22, 2008)

Sorry to hear about the charger, that's a pretty bad failure!

If you are ok with basic soldering I've been quite impressed with the EMW 10kW charger kit (I don't have it finished yet though).
With your mechanical expertise I'm sure you could come up with a more elegant solution for the casing etc than mine.


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## mk4gti (May 6, 2011)

So did you fix the charger? Or get a replacement?


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## Yabert (Feb 7, 2010)

After try to repair charger (an explosion occur) and three explosion of each prototypes build with a coworker (the last one after the second full charge) I decided to buy a new Elcon 1500W from Rebirth auto.

So the EV Grin is come back since few weeks and I try now to film some impressive performance with this little beast. I hope to have a nice video in couple weeks.

The Soliton 1 performance data give me a good new. My battery pack is able to supply 125v at 1000A to the motor terminals. 125 Kw for this little Smart is really fun!

And I add a cool pic from this summer. 
I have to say, maybe than Corbin and his bug have his unicycle, but me and my Smart have my dirt jump bike!


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## Yabert (Feb 7, 2010)

Longest trip ever done yesterday! 73 Km (45 miles) and EV Display showing 29% Soc.
So, theoretically that give me over 100 Km (62 miles) of max range.

Flat ground here, the speed was around 55-80 Km/h (35-50 mph), the wind was low and the temperature at 15°C during the trip.


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## mk4gti (May 6, 2011)

Yabert said:


> Longest trip ever done yesterday! 73 Km (45 miles) and EV Display showing 29% Soc.
> So, theoretically that give me over 100 Km (62 miles) of max range.
> 
> Flat ground here, the speed was around 55-80 Km/h (35-50 mph), the wind was low and the temperature at 15°C during the trip.


Wow that's great, Yan ! Congrats !


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## filip (Nov 4, 2012)

Hey Yabert,

I have been reading through this thread and I couldn't find any info about the original ICE equipment weight.

Did you have a chance to weigh the engine, the fuel tank, cooling system, gearbox etc.?

AFAIK the ICE smart 450 weight is 730kg, so I was wondering how much is it without the ICE components (but with the gearbox left in the car).


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## Yabert (Feb 7, 2010)

Hi filip

I don't take the time to weigh the ICE.

Lets say 865 Kg right now and we need to remove 136Kg for battery pack, 60Kg motor, 45 Kg VW transmission and adaptor and 14Kg for controller that give 610 Kg.
That is 120 Kg for ICE + transmission + radiator + gas tank + 12v battery.... hummm that seem inaccurate!

From memory, if I compare with the 91 Kg electric motor I weighed, the ICE and his transmission weigh around 140 Kg (a guestimate based on 4 arm who had lifted it).


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## Yabert (Feb 7, 2010)

I done a bit too much drift with my car there day (I shoot few video).
The rear tires will need to be changed soon!...
Both side are pretty slick and few holes started to appear.


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## skooler (Mar 26, 2011)

I like the cdi sticker....


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## Yabert (Feb 7, 2010)

skooler said:


> I like the cdi sticker....


Well, no Common rail Direct Injection diesel engine inside since a while now...


*10 000 miles* done now. Few update.

First, I replaced the old lead acid 12v auxiliary battery (a crappy 7Ah battery find in a junk yard) by a 12.8v battery build with 2.3Ah A123 cells. All work fine since a month now because I top balanced each cell and my DC-DC only charge to 13.5v (3.37v per cell).

And I used a cell phone with speedometer appliction to verify the real top speed....I release the throttle at 164 km/h (102 mph)...

It was not really fun to drive at that speed in a Smart fortwo at 6°C under rain with slick tires in mind! So I release the throttle and I will verify real top speed another time. It's not really important after all compared to fast acceleration


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## cpct (May 31, 2012)

Yabert said:


>


Haha, this is awesome! And a lot faster than the original car then


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## leonheart (Mar 2, 2011)

Great work, I didn't hope so much for this smart when you started. 
The wheelie's photo is enjoying me even if the car is yours


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## Yabert (Feb 7, 2010)

leonheart said:


> Great work, I didn't hope so much for this smart when you started.


You underestimate me since my goal since the beginning (2010) was to build a powerful and fast electric Smart Fortwo...

It's just a bit sad I can't obtain a real 160-170hp from my motor because my battery pack isn't powerfull enough (roughly 125hp at this moment).
Maybe I will obtain it in the next few years with improvement of battery technologie. Swap the battery pack isn't a huge job.


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## Yabert (Feb 7, 2010)

An interesting thing happened yesterday...

I've only been able to reach a range of 37 km (23 miles)...
Temperature was around -20°C and after 36 km (mostly highway speed), my EV Display show me 25% SOC and I couldn't maintain 100 km/h because the battery pack sag at 125v (Soliton 1 limit power under sag).
By chance, my destination was almost reach.

So, up to 100 km of range with proper conditions (summer, lower speed (200 wh/mile)) and as low than 37 km with bad conditions (winter, 1500w heater, highway speed (400 wh/mile and lower battery capacity)).


Advice for those who convert a car who will be drove in cold weather, warm the battery and calculated your expected range in worst condition (my battery heater isn't powerful enough,only 125w).


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## Yabert (Feb 7, 2010)

After few months to procrastinate, I finally edit a small video of the Smart during last summer.
Now, you know what I talk about EV grin!

http://www.youtube.com/watch?v=eSOCvnaIFKE


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## marc02228 (Jan 15, 2011)

Yabert said:


> After few months to procrastinate, I finally edit a small video of the Smart during last summer.
> Now, you know what I talk about EV grin!
> 
> http://www.youtube.com/watch?v=eSOCvnaIFKE


Haha, really great video.

At 0:38, the front wheels didn't notice, that the car is moving


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## Yabert (Feb 7, 2010)

Yeah! 
My friend said to me: I think I can do a burnout by stopping the car with the front wheels!
My answered: No!
My friend: I will try!
Me:


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## Doctorbass (Dec 12, 2008)

Nice video Yan!

That is convincing!

How much power you were using during that video and how weight is the car ? 

That would be nice to see you on a drag racing strip !

Doc


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## Yabert (Feb 7, 2010)

Thanks Doc!

I limited the power by the controller to 125Kw (125v after sag and 1000A). This (not so) little Smart weight 1900 lbs (865 Kg).


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## Yabert (Feb 7, 2010)

I recorded new record this morning.... *500wh/miles*!

That happened during a small stretch of flat road at 35 mph. The cause? -27°C this morning!

It's crazy, at this temperature, the transmission oil is more like grease (despite I use full syntethic) and the battery sag is insane!
I had hard time to maintain 52 mph on the highway because my battery can only supply 120A and the sag reach 125v at 40% SOC.

Well, from 125Kw of peak power at +27°C to 15 Kw of peak power at -27°C....

One more time, if you have a real winter where you live, warm your battery! And now, I think about transmission oil heater for the next year. I guess a little 100-200w of heat will improve transmission efficiency considerably.

The good news, despite this low temperature, the Soliton 1, the Impulse 9 and the DC-DC converter seems to work properly.


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## matthieu149 (May 9, 2011)

A battery heater might be useful then! 
How about your 1500W cabin heater, was it able to provide some noticeable heat?


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## crashedup (Oct 28, 2008)

didnt you put in heater elements in youre battery box?


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## favguy (May 2, 2008)

Hi Yabert,

How are you managing to charge at such a low temperature?


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## Ziggythewiz (May 16, 2010)

Cold sucks. I found even 0 deg C transmission oil acts like the parking brake on my bug.


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## Yabert (Feb 7, 2010)

Some answers for you guys...



crashedup said:


> didnt you put in heater elements in youre battery box?


Yes, I don't have choice, if no, the cells don't take any charging current below -10 to -15°C. I have a 18 feets easy heat pipe heater (pic) in the bottom of my battery box. It supply only 125w of heat and that is my problem when the temperature drop too low.
And because of all this, I'm almost sure than battery plating (battery deterioration) happened when I charge at this low temperature.



favguy said:


> Hi Yabert,
> How are you managing to charge at such a low temperature?


Heating is an obligation. 



matthieu149 said:


> How about your 1500W cabin heater, was it able to provide some noticeable heat?


Noticeable? Eeeee, yes. Passing the air temperature from -27°C to -10°C is a noticeable change, no? Hahaha!..
A 3 to 5 Kw heater would be really more interesting for the 20-30 days a year when the temperature is below -10°C.



Ziggythewiz said:


> Cold sucks. I found even 0 deg C transmission oil acts like the parking brake on my bug.


Yea, it's crazy! On the firsts 4-5 Km, the car acting like if regen was activated when I release the throttle (I don't have regen!).
The car slow down very fast.


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## mk4gti (May 6, 2011)

So you're only heating when charging/overnight ? (assuming it's plugged into a 110V AC outlet).

When you get home at the end of a day, is the pack below allowable charging temp?

Could you add another heating cable?


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## Yabert (Feb 7, 2010)

You are right!
And because I'm charging at work, my battery pack is warm up by the 120v AC roughly 22h per days when temperature is below 5°C (around 100 days / year).

I think than it's inconceivable, with typical use, to don't heat the battery pack for 8-9h per day (example: at work) when the temperature is really cold (-10 to -30°C).
So you need a 120v AC plug at work or use the battery energy to heat the battery itself.


I think than 250-300w of heat in my battery box would do the job and I can add couple of feets of heat wires inside my battery box. But that imply a serious work than I'm not interested to do since temperature below -20°C only happen 4-5 days a year or less.


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## JRP3 (Mar 7, 2008)

It looks as if your heating cables are the type with a built in thermostat. If that part is in the battery box it may be turning off the cable before the batteries get very warm.


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## Woodsmith (Jun 5, 2008)

Have you thought about heating your transmission too?

You could add heating to a separate oil sump, or just add heating to the underside of the trans case maybe.


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## Yabert (Feb 7, 2010)

JRP3 said:


> It looks as if your heating cables are the type with a built in thermostat.


Right! But I've bypass it of course.
It was originally designed to close around 4°C.



Woodsmith said:


> Have you thought about heating your transmission too?....., just add heating to the underside of the trans case maybe.


Yeah, it was exactly what I had in mind!


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## Yabert (Feb 7, 2010)

Here a cool pic of my electric Smart trying to pass over this winter with those temperatures (-27°C to 10°C) and the snow.... side by side with others gas burner monsters!


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## Ziggythewiz (May 16, 2010)

Mix some glue with the snow and you could have an awesome mobile snowman!


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## Yabert (Feb 7, 2010)

20 000 Km now (12500 miles) and just a nice picture of my Smart who trying to survive to this winter.


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## crashedup (Oct 28, 2008)

Did you ever say what youre 0-100km/h time was?


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## Yabert (Feb 7, 2010)

crashedup said:


> Did you ever say what youre 0-100km/h time was?


Yes...


Yabert said:


> I tried a 0-100 km/h using only third gear: 8 sec.
> Not bad considering 800A battery limited (15-20% power staying available)..... Oh! and a 220 lbs passenger (over 10% of the total weight). Haha!
> 
> The acceleration is way more impressive in second gear, but my bad shifting skill at 70 km/h ruin my time (same 8 sec using two speed).


And I have to add that if I had a clutch, the 0-100 km/h should be possible around 6 sec.
But no clutch, so I play in second gear between 0 and 70 km/h. No so bad.... in fact, it's awesome


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## Yabert (Feb 7, 2010)

Some news. 22 000 km and still counting.
Last week end, I decided to do a kind of cleaning for the beginning of spring.
I've passed compressed air inside the motor and a lot of carbon dust was expulse from it.
I clean the lugs and bus bar with scotch brite and I've add new layer of NO-OX.
I verified the brush and I think they are roughly at 40% of their life. No so bad considering the temperature at what they works (30°C to -25°C) and they pass 1000A almost each day.
I think the small blue line you can see on edge of each commutation bars indicate well than they receive a lot of amps each time I push the throttle to the floor...
You can notice dual groove where the brush touch. Those one was created during the first 3000 km when I used H49 brush at low temperature. The wear seem stabilized since this time.

After all this, I put back the cover and I hope to drive another year without problem.


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## matthieu149 (May 9, 2011)

Hi Yan!
I noticed your smart is on kijiji!
May I ask you what kind of project you have in mind?
I hope it has wheels, an electric motor and a lot of power!


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## Yabert (Feb 7, 2010)

matthieu149 said:


> May I ask you what kind of project you have in mind?


Something more comfortable, 4 places (if possible), more powerful, more range, build better and probably the most important, with a better aerodynamic.
But because I'm almost allergic to FWD car, find a proper donor car is challenging.

Of course, my Smart isn't sold yet...


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## puddleglum (Oct 22, 2008)

Read through a lot of your thread today, awesome build. I saw that your forklift motor didn't last too well, but Major thought it had been faulty in the first place. You were concerned at the time that it over sped. Do you recall what speeds you were running on the motor back then? The impulse 9 has obviously been a much better choice. I hope the one I'm going to use will fair better, but then I don't plan on your level of performance either. I'm wondering if incorporating a rpm limiter might be even more important on a forklift motor. I was wondering where you got your varnish and tape, did you go to a motor rebuilder?


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## Yabert (Feb 7, 2010)

puddleglum said:


> The impulse 9 has obviously been a much better choice. ... I'm wondering if incorporating a rpm limiter might be even more important on a forklift motor.


RPM limiter is as much important for a Impulse 9 than with a forklift motor because in fact both are similar motors.
My forklift motor has exploded because 150v was applied to his terminals without load and it probably spin at over 10 000 rpm.
If I do the same thing with my Impulse 9, I'm sure it will also explose.... especially because the Impulse 9 spin faster per volt without load compare to my old forklift motor.
The trick is to install the rpm limiter before explode the motor...



> I was wondering where you got your varnish and tape, did you go to a motor rebuilder


They come from McMaster-Carr.


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## fsadighian (Oct 18, 2012)

Hi,
I'm about to convert a smart to electric. Do you guys have electric circuit diagram of the 2006 model year?
Thanks


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## Yabert (Feb 7, 2010)

fsadighian said:


> Do you guys have electric circuit diagram of the 2006 model year?


No, but if you find it, please let me know.


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## SyCo (Feb 15, 2008)

matthieu149 said:


> Hi Yan!
> I noticed your smart is on kijiji!
> May I ask you what kind of project you have in mind?
> I hope it has wheels, an electric motor and a lot of power!


Is it sold ?  Someone can give me the ad number or link on Kijiji ??

Really nice car btw


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## Yabert (Feb 7, 2010)

*26 000 Km* done! But all will change in the next weeks because I will park the car for all summer. I left all and I will start to travel from Québec to California in bicycle at the beginning of june. Around 8000 Km, three months and lots of adventure!

Still no major problem with the Smart. The performances are there with the recent weather (+15 to +25 °C). So the accelerations still continuous to be awesome and the range is greatly increase comparing to winter weather. It's just crazy to notice than I can use on the same highway 24 Kw in winter and as low than 12 Kw in summer...

I've changed the VW transmission for a new (old) one, but the sound of gearings remain similar at high speed. Pleasant sound at city speed, but disagreable on the highway. Lot of working hours for a little change.




SyCo said:


> Is it sold ?  Someone can give me the ad number or link on Kijiji ??


Not sold yet, but considering my summer plans, I will keep the car.


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## MalcolmB (Jun 10, 2008)

Enjoy your travels and time out Yabert. I'm sure you'll come back with lots of new ideas.


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## RIPPERTON (Jan 26, 2010)

Awesome build Yabert.
did your Smart have airbags ?
if so, did you keep them for the Engineering certificate or just get rid of them ?


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## Yabert (Feb 7, 2010)

Hello all.

I'm just coming back from my 7 months bike trip across north america (10 000 miles, Quebec, Canada to Cancun, Mexico): http://quebeccalifornieavelo.blogspot.ca/
I've put my hands on my Smart. Some problems happen during my trip.

1-My brother drove my Smart on 3000 km, but after the Soliton 1 decided to partially die and needed to by return to Evnetics for a repair. I suspect the strange problem of fast on / off ''(Short cycling warning: Rapidly turning the ignition on/off/on before the controller has had a chance to discharge its capacitors completely may result in controller damage. As a rule of thumb, waiting 3 seconds is sufficient (or 10 seconds for Shiva)''.

2-After, my brother tried to reconnected all the parts, but my DC/DC converter decided to die. In fact, during the time that the soliton was in Florida, my small 12v back-up battery was dead (2-3v) and when all was reconnected, the DC/DC suffered from a destructive overload caused by the bad battery.

Now, I've bought a new DC/DC (60$) and all work well.


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## Yabert (Feb 7, 2010)

ekthor said:


> 1) You said you started with one VW transmission, then you changed it for another. Why? Is it the same model? Do you know what VW transmission boxes (models) are compatible with the Smart?


VW transmision because high torque would destroy the original Smart transmision. On regular convertion (regular power) the original transmision is sufficient. VW transmision aren't compatible with Smart car (custom supports).



> 2) Did you have any problem with your batteries? Where did you buy them? Will you use those again or will you go for prismatic cells?


No problem at this moment. China. No, absolutely not since the Calb prismatic are there.


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## RIPPERTON (Jan 26, 2010)

Yabert, move to Florida before you die too.

air bags ?


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## mk4gti (May 6, 2011)

Yabert said:


> Hello all.
> 
> I'm just coming back from my 7 months bike trip across north america (10 000 miles, Quebec, Canada to Cancun, Mexico): http://quebeccalifornieavelo.blogspot.ca/


Yan, I am amazed at your trip. congrats !


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## jerjozwik (Dec 8, 2013)

impressive, ill need to do a more detailed reading in the future.


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## jumpjack (Sep 9, 2012)

Yabert said:


> Headway cells holder.


Where did you buy these "hex holders", or "triple holders", or whatever they are called?
I bought some from Lipopower.de .... but I think they're fake! They have no screw hole in the center, and they're slightly smaller than cells (1/5 mm?) , which then are very hard to fit into them! 



Yabert said:


>


Interesting images!
Maybe did you also dismounted the positive end? It would be interesting to have a look at safety mechanism.


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## z_power (Dec 17, 2011)

jumpjack said:


> Where did you buy these "hex holders", or "triple holders", or whatever they are called?


..."honeycomb holders"?


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## Yabert (Feb 7, 2010)

jumpjack said:


> Where did you buy these "hex holders", or "triple holders", or whatever they are called?


Directly from Headway...


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## jumpjack (Sep 9, 2012)

I need an European dealer... :-(


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## Yabert (Feb 7, 2010)

I've participated at my first EV regroupment: http://insideevs.com/electric-vehicle-gathering-world-record/

It was really interesting to see all organisators and others EV owner ask if my Smart is a Smart ED or a converted Smart...


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## asimor (Nov 14, 2012)

Yabert said:


> Hello all.
> 
> I'm just coming back from my 7 months bike trip across north america (10 000 miles, Quebec, Canada to Cancun, Mexico): http://quebeccalifornieavelo.blogspot.ca/
> I've put my hands on my Smart. Some problems happen during my trip.
> ...


Yabert,
I read all, your project is wonderful!!!. But I was wondering why you do not use AC motor?


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## Yabert (Feb 7, 2010)

asimor said:


> your project is wonderful!!!. But I was wondering why you do not use AC motor?


Thanks!
DC for: 200$ forklift motor and over 200 lbs-ft of torque with 1500$ 1000A controller (was the base plan...).
Or simply watch my avatar


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## Yabert (Feb 7, 2010)

My car approaching 40 000 km (25K miles) I've took the last week end to change my old VW transmission by a rebuild transmission (old one with new bearings).
I've now a electric car who stop to do weird mechanical sound (old bearings). I'm really happy to now drive the Smart in silence.

By the same time, I've take the time to verified the motor brushes (almost 75% used), blow a lot of carbon dust out of the motor (at least 10 minutes of compressed air in all direction) and verified the general health of the motor (It lost a bit of epoxy compound used to balance the armature).

What do you think about my brush collector?
I think drive the Smart with motor Amps limited at 600A for a week or two because I've remove all the brushes during cleaning. Just to give it a chance to seat well before restarting to push 1000A on it!


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## toctoc1980 (Feb 14, 2015)

Yabert said:


> I've participated at my first EV regroupment: http://insideevs.com/electric-vehicle-gathering-world-record/
> 
> It was really interesting to see all organisators and others EV owner ask if my Smart is a Smart ED or a converted Smart...


We are able to see my Prius 2004 i have converted to PHEV on the second picture!


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## jumpjack (Sep 9, 2012)

Yabert said:


>


This kind of assembly slightly worries me: did you use head-less screws to join together couples of cells? If so, then you probably screwed them down to the internal metal plate of the cell; but this is a* big mistake*! Doing that prevents overpressure safety mechanism to trigger in case of cell failure!


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## Duncan (Dec 8, 2008)

Hi
I use similar Headway cells
The answer to your problem is simple
One end does not have the valve - its simply a threaded pocket
(1) do some measuring
(2) select grub screws of the correct length
(3) wind them into the non valve end (negative end)
Then if you have done your measurement correctly you can't screw into the valve

Dead simple - I'm sure Yabert did it that way


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## jumpjack (Sep 9, 2012)

This looks like a good method.... unfortunately I think he did the opposite! I see screws already screwed into positive ends of cells in the picture.


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## jumpjack (Sep 9, 2012)

P.s. You can identify vented side by the venting holes.


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## Yabert (Feb 7, 2010)

jumpjack said:


> I see screws already screwed into positive ends of cells in the picture.


Right. I done this because the positive end is way stronger than the black negative end. 
I use 10mm set screw... so 5mm on the positive end with lock tight and 5mm in the negative end = All good!


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## Coulomb (Apr 22, 2009)

Yabert said:


> Important problem occur! After more than 200 recharges with my Elcon 1500w, it decided to die.


Having repaired a few of these now, I think I know what happened. Somehow, likely because the 12 V supply failed, the input relay (which bypasses the pre-charge resistors) failed to close, and this makes the charger operate through these two 150 ohm resistors in parallel (effectively a 75 ohm 4 watt resistor in two parts). This can quickly overheat the resistors. If the failure mechanism includes the bridge rectifier going short circuit, this effectively puts the 75 ohm resistor across the mains input. For a 120 V mains input, that's about 192 W (a 48x overload). For 240 V input, it's four times that. For added smoke, they use carbon resistors (which leave that black muck everywhere), and they can fail *lower resistance*. This makes the power dissipation even higher, yet it still can often be less current than necessary to trip your breaker or blow the input fuse (20 A).

Usually, the resistors will be a charred mess, but the charger is still very much repairable. (Unlike your case, I'd say.) When I replace those 150 ohm resistors, I use wire-wound types, which will likely open circuit under even moderate overloads (like 2x or more). I wish that the charger manufacturers would do the same. In your case, it looks like the resistors were overloaded for a very long time, and there was severe heating. The input relay is right beside those pre-charge resistors, so I'd say that the severe heat from the resistors caused the relay to burn up. That's why you can see charred relay; it likely was not the relay that failed (though it's possible that the contacts failed to close when the coil was energized), but almost certainly it was a victim of the heat, not the source of it.

Ever since seeing your failed charger, I've been wondering why the relay appeared to cause such destruction. My apologies if this has been gone over previously.

Now as to the reason that these resistors tend to burn up... that's another story, and I don't know the full answer. I came across your post from years ago in this thread researching it.


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## Yabert (Feb 7, 2010)

It's time to give news because many things happened since my 40 000 km update. I will tried to do short...

So, I shared my Smart to my brother during the last year because I lived in France for 9 months. He drove my car during few months and one morning my Soliton refuse to work. 
He decide to store the car and he forget to charge it during few weeks when temperature was around -10 to -25°C (14 to -13°F).
Of course, the 12v system and the BMS drain the main battery down to 0%.

Well, I came back to Canada to discover a battery at 4 volts (from 154 nominal) and after few recharge test it's appeared than half the cells don't stay around 3,2v after few time (from 24h to a week).
So I shipped my Soliton to Evenetic for repair and I started to remove my old battery to be able to insert my chevy Volt battery.
After the cleaning of my battery I was happy to see the good physical shape of the pack I designed and builded 4 years ago 

About the Volt battery, my initial plan was to sale my Soliton 1, buy a Zeva controller and build a 135v and 135Ah (18 kwh) battery pack from nine 12S 45Ah chevy Volt battery.
But after many measuring of my Smart, it's clear than a square pack of 30 x 30 x 12'' can't easily enter in my car.
The 144v Zeva controller can't accept over 175v, so I had to choose between build a configuration 90v and 180Ah (16 kwh) or a configuration 157,5v and 90Ah (14 kwh) or use my Soliton and build a 180v 90Ah battery (16 kwh). I choose C.

More news to come.


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## Moltenmetal (Mar 20, 2014)

I think your brother owes you beers for the rest of your life...

Good thing you got that Volt pack!

Confident you'll get it back together and still have an amazing, unique car!

Bonne chance!


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## puddleglum (Oct 22, 2008)

Yabert said:


> Well, I came back to Canada to discover a battery at 4 volts (from 154 nominal) and after few recharge test it's appeared than half the cells don't stay around 3,2v after few time (from 24h to a week).


Are you saying that you were able to revive half the cells from you pack and they are okay? I am surprised that any of them would be any good after that.



> But after many measuring of my Smart, it's clear than a square pack of 30 x 30 x 12'' can't easily enter in my car


Were you able to get the whole pack assembly with all the accessories? That looks like a pretty good score. Do you have your dimensions correct? It looks bigger than that.


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## Yabert (Feb 7, 2010)

Moltenmetal said:


> I think your brother owes you beers for the rest of your life...


Well, I'm more frustrating against the Soliton. Without his fault my brother could have enjoy to drive the Smart year long.



puddleglum said:


> Are you saying that you were able to revive half the cells from you pack and they are okay?


Yes. In fact, all the cells came over 2,5v after some recharge test.
Now, few weeks later, only half the cells stay at 3,24v (see pic). Of course, I don't know the capacity lost and the increase of internal resistance for those cells.



> Do you have your dimensions correct? It looks bigger than that.


Yes, each 45v and 45Ah battery (12S) are 9,5 x 9,5 x 11'' and weight 42 lbs).


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## Yabert (Feb 7, 2010)

So, my plan for my Volt battery is to permanently assemble two pack of 24S with new end plates. After, I will be able to parallel those two pack to create a 90v and 90Ah battery.

At the moment, I think use TIG weld to connect cells terminal together with a copper flat bar from a section equivalent to 4 AWG.

4 AWG seem enough to me because:
-Fusing currents over 900 Amps
-In best case there will be no current to flow between two parallel cells.
-My Smart will only need around 100 Amps or less from the battery to move.
-Worst case, during hard acceleration my Smart will need around 800 Amps for a second or two. Let say the first parallel cells is in really bad shape and the second one in good shape. Cell 1 give only 200 Amps and cell 2 give 600 Amps. That 400 Amps who pass by the connection. Not too bad considering 1-2 second and 1 foot long 4 AWG bar...

Any thought?


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## tylerwatts (Feb 9, 2012)

Yabert, parallel 2 packs 24s is 90V 180Ah. I'm sure you mean series. Otherwise sounds like a good plan.



What will happen with the old cells?


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## rwaudio (May 22, 2008)

Yabert said:


> So, my plan for my Volt battery is to permanently assemble two pack of 24S with new end plates. After, I will be able to parallel those two pack to create a 90v and 90Ah battery.
> 
> At the moment, I think use TIG weld to connect cells terminal together with a copper flat bar from a section equivalent to 4 AWG.
> 
> ...


Hello Yan, sorry to hear about your headways.

I think you are overengineering the parallel system for the packs. The volt modules are much better than any batch of LiFePO4 that I've ever tested. The cell group variance is small, very small, and if you are using all cells from a single pack I wouldn't worry much about having to carry bypass current of more than 20-50A and probably not even that much. I have 30kwh from 90 cells of two volt packs, the packs are in parallel at the block level, IE 24S module parallel with 24S module, 30S module in parallel with 30S module, 36S module in parallel with 36S module. Now I don't have great data under load, I'm not set up to measure voltage properly, however resting voltage and current under load within the two parallel strings is equal. (current measured between the two strings being the most important) They seem to share the load equally within a few amps or the accuracy of my current clamp meter. This could change 5-10 years down the road as the pack ages but likely not to any significant extent.

Do you know the awg of wire that feeds the BMS connectors? I've never pulled a top cap to find out. If I were to parallel on the cell level it would be using the same awg of wire with a couple ohm resistor between the cells. The resistor would cover any significant voltage drop between the cells (but would likely be a few mv) but slowly allow the cell groups to balance when at rest.

In short if you have a 200A vs 600A variance between parallel groups they probably aren't healthy enough to go in a car.

Other than the constantly dropping voltage during discharge (hard to get use to coming from LiFePO4) these are the best cells I've ever used, that comes from my long list of Headway, A123, LiPo, Thundersky, CALB, Sinopoly and some new and recycled 18650's. Headway and Thundersky (and some of the 18650's) were the worst of the cells I tested, I think you'll be very happy with the performance of the Volt pack. 

Put a couple of 12s or 24S packs in parallal, at the module level NOT cell level (with the same length of cable to keep currents equal) and do some testing and see how well they share current. I bet they're closer than you think.


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## puddleglum (Oct 22, 2008)

rwaudio said:


> The volt modules are much better than any batch of LiFePO4 that I've ever tested.
> Other than the constantly dropping voltage during discharge (hard to get use to coming from LiFePO4) these are the best cells I've ever used, that comes from my long list of Headway, A123, LiPo, Thundersky, CALB, Sinopoly and some new and recycled 18650's.


So are you saying you would choose these Volt cells over your CALB cells?


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## rwaudio (May 22, 2008)

puddleglum said:


> So are you saying you would choose these Volt cells over your CALB cells?


Without hesitation yes!
CALB cells are good, don't get me wrong (I use them in my car) and if you have money to burn buy them, they are easier to work with because of their brick like shape. On the other hand the Volt pack is arguably better quality with integrated liquid heating/cooling passages. If they will physically fit in your build the value is unbeatable at the moment.

I have a 944 with 16kwh of CALB cells, I just built a 914 with 30kwh of Volt packs, the volt packs cost less than half as much as the CALB's or less than 1/4 the price for the same capacity, that's hard to beat.

I think Yan's car will run for many years to come on the volt pack.


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## Yabert (Feb 7, 2010)

rwaudio said:


> I think you are overengineering the parallel system for the packs.


Yeah! Probably, but parallel at cell level seem the most reliable way to do for me...


> Do you know the awg of wire that feeds the BMS connectors?


No. Probably between 22ga and 28 ga.



> Put a couple of 12s or 24S packs in parallal


Should be the easiest way to do. Parallel each 12S module is easy to do.
That could be my solution...
Well, I think I will start by testing some copper welding with a TIG and after I will be able to know if the extra work worth the pain.


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## Yabert (Feb 7, 2010)

So, I show you my battery box.
It integrated a complete 16 kWh battery from a chevy Volt. No water cooling, but 210w of wire heating (30 feets).
You can see the clear casing who will be fix to the car and the two 90v 90Ah batteries will be screwed to this casing by the blue end plates.
There is 1/2 inch of clearance all over the battery to allow the insertion of thermal insulation. I planned 1" for the top.
All parts are aluminum. Dimension are 44x20x12'' (112x51x31 cm).
Only 20 lbs (9,1 kg) for the battery box itself with covers and supports.


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## Old.DSMer (May 18, 2012)

Looks like a good plan, Yabert. You mentioned TIG in an earlier post, so I assume you will be welding the box. Curious what thickness you chose? I'm guessing 1/8" or 3-4mm based on your weight estimate? From my experience, 1/8 is nice to work with. I find anything thinner is difficult to control heat and warping. I ended up needing 1/16 backing bar when I welded mine cause I kept burning through the light gauge corner seams.


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## Yabert (Feb 7, 2010)

Today was the great surgery. I removed the thin sheet metal under the seats.
I think it will be easier for everyone to see where will be integrate my battery pack now...


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## Yabert (Feb 7, 2010)

Old.DSMer said:


> You mentioned TIG in an earlier post, so I assume you will be welding the box.


No.
Like you can see on the pictures, the side walls of my battery box will be the structural beams from the Smart. I will simply fix, with 28 screws, the battery box at the Smart ''frame''.
I plan to add silicone all around to be water tight / splash proof (kind of...).

I've used 1/16'' aluminum 5052-H32 for the box.


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## Moltenmetal (Mar 20, 2014)

Since you drive the Smart in winter, and they salt the roads in Quebec, you might want to give some thought to the galvanic cell which will be set up between the aluminum battery box and the steel of the Smart. The steel is what will corrode. For one thing, I would recommend stainless steel screws, as steel screws will likely be rusted very quickly. If you can put a nonconductive gasket between the steel and aluminum at the contact point, that would be good too- a strip rubber gasket rather than just silicone RTV sealant would be better, although you can go around the entire seam with that later if you wish. Keeping the two metals from being immersed at their junction with salt water is most important, as is a good durable coating on the steel parts.


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## Hugh-Falls (Aug 9, 2010)

Before it is too late, please abandon the idea of using 1/16 aluminum as a structural member in any battery box especially in a steel bodied car.

It is not too late to design and build a substantial steel angle iron structure to support the batteries. Even then, the use of a fully supported aluminum box to keep out the elements and protect the batteries is highly questionable. Something like PVC plastic sheet would be a better choice.

You really do not need all the complications and corrosion problems that will result from using the aluminum.


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## Duncan (Dec 8, 2008)

My tuppence worth on the corrosion issue
A few years ago I would have been much more worried about using aluminium,

But paints are so much better now - I would be looking to do two things

(1) ensure that a modern two part paint is used and that there are no gaps
(2) making sure that there is nowhere that mud can hide and stay wet


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## Moltenmetal (Mar 20, 2014)

Duncan, this is Quebec and the roads will be white with salt in winter.

Aluminum in dry spots is no problem, but any dissimilar metal joint wetted with concentrated brine will rot irrespective of what you paint it with- remember he's using screws, not bolts, to hold these boxes on.


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## Duncan (Dec 8, 2008)

Hi Molten
That was definitely true with the old paints - I'm less sure about the new paint systems

The old paints were porous - if you left a painted part immersed in water the water would go through the pores and "jack" the paint off the surface

I will have to do some testing with the new paints - I think they are now OK - but I haven't tested one!

As far as screws are concerned I would expect to paint twice - once before assembly and then again after its all together - including the screws - not a bad idea with bolts as well


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## Yabert (Feb 7, 2010)

Moltenmetal said:


> ... the galvanic cell which will be set up between the aluminum battery box and the steel of the Smart. The steel is what will corrode.





Hugh-Falls said:


> Before it is too late, please abandon the idea of using 1/16 aluminum as a structural member in any battery box especially in a steel bodied car.


Fair points guys.
But I'm not too worried about the galvanic corrosion because, as Duncan said, the steel parts cut in the Smart will be painted. Also all the junctions between aluminum and paint steel will be seal to keep out salt water and dust.

Maybe there was a language misinterpretation about the word screw, but I'm talking about socket head cap screw with lock nut (so bolt) on the other side of the steel frame to fix the box in place.
So, despite stainless steel screw are good for some applications, in his case, I will use stainless steel washer with steel screw who have 2,4 time the tensile strength of similar stainless steel screw.

About the 1/16 aluminum as a structural member, I will install stainless steel strap under the battery box to release stress on the aluminum. Exactly like I've done on my first battery box (1/16 aluminum 5052-H32 who last well during four winters / 45 000 km, see picture or http://www.diyelectriccar.com/forums/showpost.php?p=680074&postcount=274).


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## JRP3 (Mar 7, 2008)

Steel or stainless steel screws or bolts passing through aluminum should have a coating on them. Some anti seize, thread sealer, or silicone grease would probably be enough.


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## Yabert (Feb 7, 2010)

After some tests, TIG welding thin copper bar is fairly easy. I've done ''spot weld'' to be sure to don't over melt copper.
So, with four 90v (24S) 45Ah pack from the chevy Volt I will build two 90v (24S) 90Ah battery.
6 AWG solid copper is easy to find here, so that will be my ''bus bar''. I plan to stamp the round wire at each end to do a flat bar easier to weld (12 awg example in picture).


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## tylerwatts (Feb 9, 2012)

Hi Yabert. How do 4 90V modules give you 90V at 90Ah? You meant 180 V right? It looks like a very good pack.


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## Yabert (Feb 7, 2010)

tylerwatts said:


> Hi Yabert. How do 4 90V modules give you 90V at 90Ah? You meant 180 V right? It looks like a very good pack.


Of course...


Yabert said:


> ...I will build *two* 90v (24S) 90Ah battery..


So, the final battery will be 180v 90Ah.

Well,after some search, solid AWG 6 is hard to find in Quebec. By chance, US isn't too far and it seem every hardware store have 25' solid AWG 6 bare copper wire in stock.

*I would like opinions here*. What should be the best cover/insulator for my 48 bus bar build with AWG 6 (diameter 0,162")?

Shrink tube?
Insulating varnish?
Nylon tubing?
Really cheap polyethylene tubing?(enough?)


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## Yabert (Feb 7, 2010)

I started to assemble the battery in his final configuration (180v nominal 90Ah).
The news end plates are fitting well and I have now two 170 lbs battery. I've cut the 6mm rods and I created new threads but I also add longer 6mm threaded rod who help a lot to compress the cells. I will cut the over length.
All the cells are balance at around 3,79v and they are ready to be connect in parallel.
You can also see my new battery box who fit well in the Smart.

Next step is to fix the battery box to the Smart frame and weld the bus bar between parallel cells.


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## Hugh-Falls (Aug 9, 2010)

Yabert said:


> ...........*I would like opinions here*. What should be the best cover/insulator for my 48 bus bar build with AWG 6 (diameter 0,162")?
> 
> Shrink tube?
> Insulating varnish?
> ...


For electrical wiring it would be proper to use electrical insulation. The 600volt shrink tube insulation would be my minimum choice, maybe even a double layer.

Most vehicle wiring makes use of stranded wire due to vibration and strain that could fatigue solid wire. Bus bars probably should be designed with some kind of strain relief built in.


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## Yabert (Feb 7, 2010)

Today, I remove the Impulse 9. It lost his epoxy compound part who balance the armature so I will send it to the motor shop.

By the same time, I remark corrosion spots under two set of brushes of the four poles. It's strange, under the first two set of brushes face to face there is no corrosion and the two other set of brushes face to face has some corrosion.
Hoping it's just because the motor don't spin since 8 months and than my armature is in good shape (fingers cross!).


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## tylerwatts (Feb 9, 2012)

Yabert I believe that the corrosion I

Is due to the polarity and the negative brushes will have the corrosion.


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## Moltenmetal (Mar 20, 2014)

There should be no voltage there when the car is just sitting, aside from the galvanic voltage between the carbon and copper. If there is a current leak, you need to fix that.

But without an electrolyte, there is no meaningful current flow between the two parts to drive corrosion.

I suspect the corroded set of brushes is in an orientation where condensation will collect, completing the circuit between the copper and graphite. The graphite is more noble, so it's the copper which corrodes. 

I know you were out of the country and left your brother in charge, but in future before long periods of storage you may want to spray some WD40 in there. It will leave some residue but that will burn off quickly in operation.


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## Yabert (Feb 7, 2010)

Moltenmetal said:


> ...spray some WD40.


Not sure about this one...

But anyway, after 4 winters and over 45K km with this motor I have to said:
*This kind of air cooled motor are pure crap in weather like here (snow, wet snow, salty road, wet dirt, humidity).*

Despite I've used a seal cover and an air filter over the commutator end all the parts are rusty (steel) or full of corrosion (aluminum). The worst is the stator pole shoes who start to delaminate because there is rust formation between the steel plate.
Picture to come!

I'm dreaming of water cooled sealed motor...


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## Yabert (Feb 7, 2010)

It's sad, I don't have good pictures of the motor before I started to clean it.
But you can although see the rust on the shoes poles despite I brushed it to remove surface rust.

My plan is to paint it with Sprayon red insulating varnish to stop the rust hemorrhage.


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## Yabert (Feb 7, 2010)

Ok, some news about paralleling the Volt modules.

My first goal was to find copper material to build my bus bar. Solid AWG 6 wire are common in US, but not here in Quebec. I finally end by choosing AWG 8 with 7 stranded. The 1000v insulating material is thick and appreciable for his toughness.
My initial plan was to create rectangle ends on my bus bars by pressing the 7 stranded. I builded a die to create rectangle and because I don't have access to an hydraulic press I first thought a multi purpose vice would be enough to compress copper, but it wasn't. So, I build an hydraulic press with my 3 ton car jack, but the result wasn't very nice. The copper wasn't compress enough.

At the end, without other choice, I decided to weld my bus bars with round end.


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## Yabert (Feb 7, 2010)

So, to do a good job, I first weld the end of the 7 stranded. This is important to fix all the copper wires and to ensure the current to flow on all wires.
After, I start to fix my bus bars to the 1 mm (0,040'') thick conductor plate of the Volt battery.

It's not super easy, it take time and the result isn't super well, but it's strong and I now have a 90Ah battery who can output over 1350 Amps.
I think it would be easier if the bus bars was a rectangular copper like 0,063 x 0,250'' or something like that because with the 7 stranded wire each small copper wire melt fast.

You will see that I've needed to build special bus bar to pass around the BMS connector. They are a little bit longer.
I also add few small plastic edge trims at those places where there is chance of contact between the bus bar and the next cell terminal.

To give you an idea to know how I've TIG welded those thin materials without overheating the cells, most of my ''spots weld'' was created in 0,5 second. A long weld was around a full second. 
I let time between each spot weld to give the chance to the bus bar to cooled down.


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## dotrick (Sep 4, 2014)

Good job!


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## pchelka (Aug 12, 2014)

just one thing from top of my head, make sure that there is no chance of cutting through cable isolation due to normal driving vibration

For example the first cell has this metal part under the cable you added. so additional padding or something just to be safe.


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## Yabert (Feb 7, 2010)

Big step done... the battery is in the Smart.
All is fitting well at the moment, but put the 1/2'' insulating foam around will be challenging because of the battery connections bar and the heating wires (black wires). There is two in the batteries and one in the bottom of the box. That will be a bit over 200w of heat.

The next steps will be later, few weeks later. At the moment, it's time to travel. In direct from Bangkok


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## tylerwatts (Feb 9, 2012)

Very nice sir. That's alot of battery!


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## puddleglum (Oct 22, 2008)

Looking good. I've been following your progress with great interest. I really like what you did with the two battery packs.


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## Yabert (Feb 7, 2010)

I restarted to work on the Smart since few days now.

The motor is back in place after a balancement and a cleaning. I think the motor shop didn't do a great job because they did some mark on the commutator after they turned/cleaned it. If this motor burn in the next few months, I will know why...

Well, I took the time to repaint most steel part of the motor to help it survive against rust.
I've also wired the heating cables inside the battery. They seem to work well. Next step is to connect it to the temperature controller.


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## Lleksam (Dec 6, 2015)

Hi just found this today, reading with interest, but wish there were photos in early posts, can thease early pictures be viewed any where please?

Steve


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## Yabert (Feb 7, 2010)

Steve, I want to thank you... I took the time to watch those pictures delete since 2010. So much good memories.
Because I've done a lot of things (good or bad) on my conversion since 5 years now and because I want to share this, I've create an album with most of the pictures delete from this build thread during the years. 
Enjoy!
https://imageshack.com/a/uyz4/1

There is also few pictures from my electric DRZ SM (motorcycle) and other project.


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## Yabert (Feb 7, 2010)

OMG than my Smart would been AWESOME by passing 1000A in his original 11" motor*.
0 to 60 km/h (37 mph) in 2,5 second with the small Impulse 9... can you imagine with this 11" monster 
Oh sweet memories.
*Deceased


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## Lleksam (Dec 6, 2015)

Thank you Yan

a picture speaks a thousand words,

(edit) Just looking through your album the interface between motor and gearbox has become clear, you used the VW flywheel and clutch, I was over thinking that

At the moment this is only a seed in my mind Im a engineer and know zero about electric cars, Im now semi retired and this would make a nice complement to current project a V8 toyota into a Mitsubishi Delica 

Steve


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## Yabert (Feb 7, 2010)

Lleksam said:


> ...you used the VW flywheel and clutch, I was over thinking that.


No, I drive clutchless (not enough place for everything in the Smart). I only use the center of a VW clutch to link my motor shaft and the transmission shaft (like the picture, but it's not my motor).


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## Yabert (Feb 7, 2010)

I did the first ride with the Smart and his chevy Volt battery 2 days ago. Exciting moment!
Well, the motor Amps was reduced to 300A so the excitement was to drive a new time this little car after his battery transplant.
The commutator end of my motor was cleaned at the motor shop so I plan to drive the car at low power for few weeks. 72v and 450A sound good to me  to take care of this Impulse 9 the time than the brushes sit properly.

You can see in pictures the Volt battery pack (16 kWh) at his place in the Smart. Under the aluminum covers I was able to add 1" of insulation sheet. So there is 1/2" all around and 1" on the top. With 230w of heat, I expect this to be enough to keep the battery at 15-20°C during the cold days.
I have also modified the original seat supports because they was fix at the place where the Volt battery is at the moment.


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## Yabert (Feb 7, 2010)

I drive the Smart since few days now. 
I've done over 250 km with the new battery and my longest trip was 60 km with 40% of charge remaining (around 0 to 5°c winter temperature).
I didn't touch the Soliton setting and believe it or not, I still drive it with 300 motor Amps.... and it's enough!
I can keep up with traffic in town using only second gear and I'm going on the highway (97 km/h - 60 mph) in third gear.
Of course I floored the accelerator often. 
From the Netgain Impulse graph, that only 37 lbs-ft of torque to move a 900 kg car. The max power released by my EV display was 21 kw. I often drive with 5 to 15 kw of power (60-97 km/h).
Well, I'm simply surprised one more time that such a low power can move my car.

Other news, My EMW 12 kw charger isn't ready at the moment so I modified my Elcon charger to be able to charge my battery up to 200v. His initial program was for 40S to 50S lifepo4 and the max charging voltage was 182v.
I don't have BMS so I top balance my battery. Each cell was at +/- 0,01v at around 3,79v when I started to charge my pack and I've balanced the cells at 4,17v. They was still at +/- 0,01 and I do my best to balance almost all the cells at 4,17v with my small 10A Icharger.


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## puddleglum (Oct 22, 2008)

Glad to hear your car is working well and also that it is working well for in town use at a low power level. I read your 72v test thread you linked to . It gives me hope that the low voltage low budget conversion I'd like to do might actually work okay. Just curious, do you think you would be getting similar results from the 11" forklift motor you used first?


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## Yabert (Feb 7, 2010)

puddleglum said:


> Just curious, do you think you would be getting similar results from the 11" forklift motor you used first?


Of course yes! Or even better.
For me it's clear, the power in would be the same, so the power out should be the same.
The only difference with my first 11" motor would probably been a faster acceleration (more torque per Amps) and the necessity to use the 4e gear on highway because this motor spin slower than my Impulse 9 with the same voltage (more torque, but less RPM).


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## Yabert (Feb 7, 2010)

Just few interesting informations for those who, like me, live in a cold weather country.

Last morning after few days without using my car, the battery pack was at -19°C (same as outside) .
I plugged my 230w battery heater for roughly 2h and the battery was at -4°C.
Take the car to do some funny drift on the snowy road. The voltage sag was bad (roughly 190v to 180v at 1 to 2C only).
After I park the car for the night and this morning the battery was at 20°C (the temperature programmed on my temperature controller) despite the -15°C of the outside.
Well, I took the Smart (battery at 20°C) drive 5 km without battery heater, stay 3h at the same place and drive back home after. The battery temperature was drop to 10°C

Conclusion, my insulated battery box is working good! Well, good enough for me


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## Yabert (Feb 7, 2010)

I drive the Smart with the chevy Volt battery since more than a month / +1000Km now.
I did a sanitary check today and I measured the 48 cells on my top balance battery.
My charger stop the charge at 195v and all the cells was equal at 4,06v. Perfect!

I was happy to confirm that all the cells was equal and now I'm more confident to use a simple Cell-Log to monitor my entire battery. See here: http://www.diyelectriccar.com/forums/showthread.php/cell-log-easy-and-cheap-bms-168402.html


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## tylerwatts (Feb 9, 2012)

Excellent news Yabert. Congrats


Tyler


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## Yabert (Feb 7, 2010)

I finally build an enclosure for my 12Kw EMW charger. It is 12x9x7'' and I like it... except one thing. If I had to redo, I will fix the control board at the bottom orange part instead of the top.
One nice thing is I designed the enclosure to be laser cut and then the bending is done by hand.

The charger is working, but at a reduced power. I set 240v 20A in and 196v 35A out (196v CV and 24A CC), but the max output is around 2,3Kw (see video).
The strange things on the screen is IN: 120v after a second despite I connect it to 240v (1:03 in the video).
https://www.youtube.com/watch?v=YzwB7RhcvOo

So, the other strange thing is the 1/2 power when you compare to settings. At 120v the power should be 1200w, but stop at around 588w (196v x 3A). At 240v, it reach 2340w instead of 4700w (196v x 24A).
The same thing happened when I tried a 4000w charge at 240v. The settings was around 8000w.
Well, I tried many different settings at 120v and 240v, but the problem remain.

Any thought?


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## PStechPaul (May 1, 2012)

See my post in http://www.diyelectriccar.com/forums/showthread.php?p=753202&posted=1#post753202


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## Yabert (Feb 7, 2010)

I did another sanitary check for my top balanced chevy Volt battery (48S, 180v nominal) after 4 months and roughly 3000 km.
Charged at 195v and all the cells show 4,06v.... excellent!!!

Also, good weather is coming back there days, so it's time to crank up the power. After 4 months of driving my Smart without problem with peak power of 35 Kw \ 450 Amps (motor side) is time come back with 120 Kw \ 1000 Amps 


I drop the idea to use a simple cell-log to monitor my battery pack because a friend of mine was able to read voltage and temperature signals from the OEM Volt BMS.
So I will use the original BMS to protect my cells.

This is a big step forward in the world of DiyEcar with OEM quality battery. 
My friend will work a little more on the Volt BMS to be able to have an useful complete BMS systems (LVS, HVS, Voltage reading on cell phone via bluetooth, etc).
I will let you know when he will be able to share more details about this Volt BMS.


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## Moltenmetal (Mar 20, 2014)

Awesome news about hacking the Volt BMS- and your success in keeping the pack balanced. Full power ahead!


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## Yabert (Feb 7, 2010)

I finally took time last week to dismantle my old Smart battery built with Headway 38120S 10Ah cells.
Despite the entire pack was at 4 volts few month ago (see here) it seem than around 25% of the cells are still in good shape  
Most show 0v to 1v, but some show an adéquate 3,15 to 3.20v.

To date, I do charge/discharge tests on many cells and they end at 7Ah to 8Ah.
Not good, but not to bad for a second life on a e-bike or home energy storage.
I plan to build a 4S 16P to have a nice 12,8v and 120Ah battery.


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## Yabert (Feb 7, 2010)

For those interested by some Volt battery stats...
Hot weather here yesterday. I start to drive the Smart with the battery at 30°C (ambient temperature). I drove 30km at 70-90 km/h with some stops.
I came back home with the battery temperature reaching 32°C.

I'm happy with that because there is probably less than 10 days a year with such temperature.
My B plan was to remove some insulating material and blow fresh air on cells terminals..., but I will not bother with this since I know this result.

To remember, my battery box is insulate and not cooled.


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## piotrsko (Dec 9, 2007)

I am getting generally the same results, except in farenheight. It is funny all these experts telling me how some theoretical paper says we are wrong.


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## EV_dub (Aug 30, 2010)

Hi Yabert...

Thanks for sharing your work...

I would be really interested to find out more about your volt BMS and any wiring diagrams for this.


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## Moltenmetal (Mar 20, 2014)

Yabert: it's high time you sent an update! If your past is any indication, you've been driving the car a lot on that new Volt pack, and even a brief "everything is great- the car is working perfectly" would be helpful!


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## Yabert (Feb 7, 2010)

EV_dub said:


> I would be really interested to find out more about your volt BMS and any wiring diagrams for this.


Sadly, I don't have a lot of info on the Volt BMS and I still drive my Smart without BMS.
The fact is that my friend was able to communicate with the BMS with an Arduino module. He created a program based on Blutooth and I seen the pack voltage - cells voltage - pack temperature on my cell phone.
That was awesome, but this set up was experimental and we were supposed to build a nice prototype.
But my friend don't have time right now since he build his proper electric motor for his hybride Subaru BRZ...

Well, despite that I drive my little Smart to work each day and everything is great.


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## piotrsko (Dec 9, 2007)

There was an article on hackaday last couple of days about a can sniffer interface that should work on volt packs. Im not interested, lived too long without it.


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## Yabert (Feb 7, 2010)

Last update was a year ago... so, now the Smart still working fine and have now over 57 000 km.
Few months ago, I tried my charger at 12 Kw on a 240v 70A EVSE just to see the capability of the charger and all was fine, except that the 14 Ga wires (battery side) didn't like it after few minutes 
I will upgrade the wires later, but at the moment the majority of the charges still continue to be at 120v 15A.

Well, I ask for some help now because I have troubles with my 12 kw charger and I want to resolve it.
The outputs of the charger are directly connect on the battery and sometime during driving the output fuse (60A) on the charger exploded. At the begening, I don't understand why, but after some reflextion, I realize that the motor controller came to suck amps on the charger capacitors during an hard acceleration event.

So I need to disconnect the charger from the battery during driving.
I can add a contactor, but I need a kind of precharge to connect the charger if no, there will by a large ''spark'' in the output charger contactor when the battery will fill the charger capacitors.

Any idea, suggestion?
Thanks


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## Duncan (Dec 8, 2008)

Hi Yabert
If you are pulling lots of current out of the charger capacitor that suggests that the voltage must drop a lot very fast
How about simply putting a low resistance power resister in series - it will heat up a little bit in normal use but stop those large currents

0.1 ohm - the Constant current charge would lose about 22 watts - but the CV part would ignore it
And if you did pull close to 60 amps it would drop the voltage by 6v - which would almost certainly mean that it would never happen


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## riba2233 (Apr 29, 2015)

How about adding a diode between charger and battery, that way you'll stop the current from going into the charger and wont be able to fill it's capacitors. Or get a slower fuse.


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## Yabert (Feb 7, 2010)

Guys, I'm a huge fan of KISS (keep it simple stupid) and it's why I like your ideas.
Riba, I'm not sure that add a diode in the circuit is a good idea because it will stop the flow in one direction, but as Duncan said, reduce the Amps flow with a resistor seem good... almost to good to be true.

If i understand correctly, when I charge at 50A the voltage drop in a 0.1 ohm resistor will be 5v (250w), but during the CV phase the voltage drop in the resistor will reduce.
Well, if this work, the main problem will be to manage the 250w of heat generate during more than a hour.
Not fun to wast energy...


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## riba2233 (Apr 29, 2015)

Yeah I think that's too much heat and waste energy, and could mess with chargers regulation. One inductor could also work (it would cancel large current spikes) but i don't know if charger would be happy with increased inductive load.


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## Duncan (Dec 8, 2008)

Hi Yabert - I had forgotten that you were using a lower voltage!

with 180v I would change my thoughts to 0.5 ohms - giving 2.5v at 50 amps and 125 watts
Or even lower!

That is for the charging

If you are blowing a 60 amp fuse by drawing current from the capacitor in the charger then that will be for a very short time 
Which means that you are actually drawing a LOT more than 60 amps for a couple of seconds

Your resister will drop the voltage MORE in that occasion




CANCEL! CANCEL!

You need a resister - that will stay in the charging circuit all of the time - an old kettle element will do
That will protect you from the spikes

THEN you need a switch across said resister - when you are charging you switch it ON
When you have finished charging and are driving you switch it OFF

No energy wasted at all!

AND

If you have to disconnect your charger it gives you a built in "pre-charge" - just make sure the switch is OFF before re-connecting the charger

I didn't make that clear - when charging your switch is across the resister - shorting it out - so switch OFF means the resister is in series - switch ON means that the resister is shorted out


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## Yabert (Feb 7, 2010)

Duncan said:


> when charging your switch is across the resister - shorting it out - so switch OFF means the resister is in series - switch ON means that the resister is shorted out


Yeah... exactly the same as a resistor is used on the main contactor of an Alltrax controller by example.


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## foxr (Apr 16, 2015)

After reading tons of tons I still didn't see it. I'm working on the plan for a smart car converted to ev(from gas) and I'm planning on using a leaf motor and custom controller similar to what arlo has done in his CRX. I'm trying to find the dimensions of what space is avail in the floor so I can get a battery plan and see what it's even capable of supporting with todays salvage batteries(volt, spark, leaf, tesla) probably reconfigured as I'll need 160kw power or roughly 215hp to reach my goals(if it can do it without a wheelie bar ;-). *the other possibility would be for me to take the entire drivetrain, suspension, wheels, display, gas pedal, shifter and basically the works out of the 54.5 front track spark ev)my daily driver) in my garage and bolt it to the rear of the smart cars 54.5 rear track width and rewire the whole setup into the smart to lose about 1k lbs if I can even fix the entire battery in there.


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## Yabert (Feb 7, 2010)

foxr, I don't know where is the problem... With my build thread you know a 16 kWh Volt battery can be inserted in a Smart and with the thread below you know than a Volt battery pack can output more than 280 Kw.
Seem like you are in business if you find a controller to power a Leaf motor at over 160 Kw  

http://www.diyelectriccar.com/forums/showthread.php/power-capability-chevy-volt-battery-109698.html


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## foxr (Apr 16, 2015)

Ok, great! Thank you. Now I'm wondering what kind of power you were putting out that caused the front wheels to leave the ground cause if it's less than 160kw, is there any real reason to get a higher power controller, this car can't drive on the street with a wheelie bar to my knowledge! lol


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## Yabert (Feb 7, 2010)

foxr said:


> I'm wondering what kind of power you were putting out that caused the front wheels to leave the ground


It's not a question of power, but a question of instantaneous torque.
My bet is I can probably lift the front wheels with only 20-30 Kw because electric motor can output max torque at low RPM and because I have a 5 speeds transmission.
When I floored in first speed, there is around 2500 lbs-ft of torque at wheel... that the trick!

High power is nice to have fast acceleration. Lifting the front wheels is cool, but doing a 0-60 mph in few seconds is way nicer IMHO!


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## Duncan (Dec 8, 2008)

Hi Yabert
What is your front/rear weight distribution?

To Foxr 
If you get your batteries way forwards you should be able to keep the front wheels on the ground


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## Yabert (Feb 7, 2010)

Duncan said:


> What is your front/rear weight distribution?


I don't know..., but way better than the original diesel Smart.

Just to clarify for everyone. My Smart never do a wheelie during normal driving when I use second gear at city speed and third gear at highway speed.
To pop a wheelie the car need to be in first gear with the motor amps at 1000A. Despite respecting those condisions, 99% of time the rear tires spin and the front don't lift 

Now you know the truth


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## foxr (Apr 16, 2015)

Yabert, that is great news!!! Yay!


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## Yabert (Feb 7, 2010)

*66 000 km* and an update.
I changed the motor brushes yesterday. It was really the time to change, copper wire of the brush has start to damage the armature. 
You can see in pictures, that two brushes of a same pole don't have the same wear. They are also comparable with new brushes.

Except that, the Smart ride fine and I use it almost everyday. 
But really, I'm tired to don't have the Chademo / Combo fast charge possibility, to only have two passagers places, to sometime have J1772 incompatibility, to ... well, I'm slowly looking to buy a regular electric car.
My dream at the moment could be to find a used Nissan Leaf at 5K$ and a Chevy Bolt battery at scrap yard and match the two


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## Yabert (Feb 7, 2010)

Another small update.
I took some time today to balance my Chevy Volt battery.
I usually charge at 196V, but to balance the cells this time, I charge up to 200V.
Over 48 cells, 46 was within 0,010V (≈ 4,15V). One has a voltage just out of the 0,010V and another was 0,030V off at 4,12V.
I added around 1Ah in this cells and added a little bit of energy in few other cells to balance all the cells within 0,008V.

I hope to drive another year without BMS and without problem.

This little Smart still beat anything at the red light and this is fun!


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## foxr (Apr 16, 2015)

So how many total KwH do you have in the car and what is it's range?


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## Moltenmetal (Mar 20, 2014)

Yabert, you mean you gave up on getting a used Leaf?!

Why would you want a used Leaf when you can drive your custom masterpiece?!

Any chance you can update the Garage with your basic stats on the car? I don't remember the details- did you fit the whole Volt pack in there? What current are you pulling now? 

Fantastic to see how stable your Volt pack is! Amazing that you can get away without a BMS for so long- I'd be sweating every time I plugged it in to charge it...


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## Yabert (Feb 7, 2010)

Moltenmetal said:


> Why would you want a used Leaf when you can drive your custom masterpiece?!


Not a simple used Leaf (or Spark EVor Golf EV or???) a used Leaf with a 40-60 kWh battery coming from another crach EV 
I want long range and fast charge... like every EV driver, no?

My Smart is nice, but it's a masterpiece with a good amount of small glitchs and low range.
It's an EV designed and built by a single guy with a small amount of money, not a production car design and build by hundred of peoples.

I'm ready to have a low cost production EV with long range, but there is not enough Chevy Bolt battery and Leaf 2018 battery at the scrapyard now


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## Yabert (Feb 7, 2010)

New update about the Smart
85000 km and still driving it almost every day.
I've done a check on the cells before another winter to come.
Charged at 197V every cells was at around 4.11V except 4 cells. Voltage was from 4.03V to 4.08V for those cells.
I added up to 13Ah to the worst cell. It seem that few cells drift and drift faster and faster as the years pass.
If things continue like that, a BMS will be need


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## Jonisingt35r (Sep 5, 2019)

Hi there, i hope to do a smart car, is the gearbox an auto? Or a manual?


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## brian_ (Feb 7, 2017)

Jonisingt35r said:


> Hi there, i hope to do a smart car, is the gearbox an auto? Or a manual?


It is an automatic, but not of the usual design. It is built like a typical manual transmission, but has motorized and computer-controlled mechanisms to shift and to control the clutch.


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## Jonisingt35r (Sep 5, 2019)

Hello brian, 

thanks for replying, great did you have any problems with the box,? and does it behave as it should do is it s smooth ride especially when you first drive off
Thinking of modding mybattery somehow, and take 12v off it some how to feed the wireing loom
What motor would you suggest would suite best for this car, Is the one you used ok, or could you think if a better one maby
and advice would be really helpfull

Thanks jon


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## brian_ (Feb 7, 2017)

Jonisingt35r said:


> Hello brian,
> 
> thanks for replying, great did you have any problems with the box,? and does it behave as it should...


I have not converted a Smart - I'm just familiar with the design of the vehicle.

The Smart transmission might be difficult to work with, because it is programmed to work appropriately for an engine. Stopping the transmission controller from slipping the clutch when engine speed drops to idle would be one problem. Changing shift points to speeds more suitable for your chosen motor could be a challenge as well.


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