# Too slow. Must go faster



## major (Apr 4, 2008)

gt40ev said:


> My project is getting closer and I've driven it around the block a few times but it's much too slow.
> 
> The car is a GT40 kit car built on a VW. It has 120 volts of 10 12volt used sealed lead acid batteries that used to be in a Ford think. Pack voltage checks out and my state of charge registers full power. The pack is seperated into 4 batteries in front, 2 behind the seats, and another pack of 4 in buried in the rear deck, all connected by 2/0 cable.
> 
> ...


Hi gt,

1) Used batteries are always suspect. If you don't have both meters, battery voltage and battery amps, get them. Then record V and I during loaded conditions as best you can. For example, what is battery voltage at 100 amps, 200 amps, or 247 amps? Maybe have a passenger take some notes.

2) Kelly controllers???? People have had problems with them. A member named gottdi is a Kelly lover and swears the new ones are good. He hates it when I badmouth Kelly. I have no idea how to tell if the Kelly controller is a good one or a bad one. If it is the problem, Kelly may replace it for you. Once you verify the batteries are good, pursue the controller.

3) Motor sounds marginally small. D&D makes a good motor. Only the 6.7 inch diameter models. In a vehicle that size I think at least an 8" motor should have been used, probably with a 600 amp controller, if you wanted decent performance. That D&D should get you up to speed with a shifting transmission. Just that it may overheat. 

I'd use the order which I listed. A bigger motor won't help a crappy controller. A good controller won't help crappy batteries. Lithium batteries would be a big help, but if your controller will never go above 300A, that will limit you to about 36 hp. 

Regards,

major


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## cruisin (Jun 3, 2009)

I would suggest that you do the following.
1) Upgrade the controller to at least a Kelly 800a
2) Upgrade the motor to a Impulse 9 (keep same bolt pattern)
3) If that is still not enough, goto Li-ion batteries.

I can help you with the motor and controller as I have some used in stock at [email protected]

I can also help you with Li-ion 18650 2.4a cells with tabs if like to solder and save some money.


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## major (Apr 4, 2008)

cruisin said:


> I would suggest that you do the following.
> 1) Upgrade the controller to at least a Kelly 800a
> 2) Upgrade the motor to a Impulse 9 (keep same bolt pattern)
> 3) If that is still not enough, goto Li-ion batteries.


Hi cruisin,

Don't you think he should see if his present system is functioning properly before buying new components?

And gt40ev,

That Kelly controller has a computer connect port, right? Are you sure you have parameters configured correctly?

major


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## GerhardRP (Nov 17, 2009)

cruisin said:


> I would suggest that you do the following.
> 1) Upgrade the controller to at least a Kelly 800a
> 2) Upgrade the motor to a Impulse 9 (keep same bolt pattern)
> 3) If that is still not enough, goto Li-ion batteries.
> ...


I agree with Major about diagnosis first, especially since you seem to be offering to sell this stuff, your advice is suspect.
Gerhard


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## Jan (Oct 5, 2009)

It's always wise to listen to Major.

p.s. That car looks really fast. Now the rest.


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## Qer (May 7, 2008)

Jan said:


> It's always wise to listen to Major.


I second that!


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## gt40ev (Nov 15, 2010)

Major, good stuff. Just what I was looking for. My voltmeter is currently wired to show how much voltage the controller is transferring to the motor but it's easy enough to move the negative lead to ground so it always shows pack voltage instead.

What exactly am I looking for? Or should I just post my results and see what the forum has to say about it?

I suspect it's the batteries. I have a battery tester that I got from Pepboys. It measures voltage at rest but also the condition of the battery underload. It's made for starter batteries but it tells the story. 8 of 10 tested great, one went to weak under load, and 1 showed almost dead under load. I'm going to charge those 2 seperately (it looks like my 120v charger isn't charging even?) before I run the tests.

With the pack full, I got the following results:

Mode Volts Current
no load, light throttle 129 50
no load, full throttle 121 60
light load, light throttle 129 75
light load, full throttle 125 100
heavy load, light throttle 120 200
heavy load, full throttle 110 350
full throttle from dead stop 115 400

All 10 batteries now read good (after charging the suspect 2).

What does this tell us?

Thanks
Tom

PS. with the 2 low batteries charged up, I got another 10 MPH


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## major (Apr 4, 2008)

gt40ev said:


> With the pack full, I got the following results:
> 
> Mode Volts Current
> no load, light throttle 129 50
> ...


Tom,

Tells us it works better with all the batteries charged  But your V and I numbers are a bit mixed. Please confirm it is battery current, not motor current. Those are different.

And do you have access to the programming port? Can you see what the low voltage cutback is set at?

major


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## gt40ev (Nov 15, 2010)

Major,

My shunt is between the contactor and the motor. Is that motor current or battery current?

The settings on the controller are:

Foot switch: disabled
Throttle effective start: 10%
Throttle effective end: 80%
max motor current: 100%
startup delay: .1 sec
control mode: speed
under voltage: 18v (the description for this reads "controller will cut back current at battery voltage lower than 1.1x the value, cut out at the value, and resume operation at 1.05x the value)
over voltage : 136v (I think this is for regen which I am not currently using)
throttle up/down rate: 15 (with fast being 1 and slow being 20)
power on high pedal disable: disabled
motor top speed: 100%
motor temp sensor: disable
controller stop output temp: 125C
controller resume temp: 110C

Do I have something set wrong?

If I'm measuring motor current and not battery current, how do I orient the shunt to measure what we're looking for?

Tom


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## Bags (Jun 20, 2010)

Love the title for the thread.

Sure, diagnosis it first, and wring the most you can out of what you've got.

I'm a new EV owner, so take this with a grain of salt. When I try to accelerate on par with normal ICE cars, it takes 800A +/- 200A. At 156V nominal on lead-acid batteries, so sagging down to 145V or so when "full". When I've tried to hold the current under 400A, it accelerates so slowly that I feel people should be honking at me. 

On flip side, though, I would love to get 40 miles per charge. I get much less than that. I'm not sure you'll be able to get 0-60 times less than 10 seconds and 40 mpc using 10 12V batteries. Unless you mount them on a motorcycle.

"YMMV"


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## major (Apr 4, 2008)

gt40ev said:


> My shunt is between the contactor and the motor. Is that motor current or battery current?


Hi Tom,

The Kelly wiring diagram shows the contactor in the battery positive line with a connection to the controller B+ terminal and then to the motor. If the shunt is between the contactor and B+ (controller terminal), then it is battery current. If the shunt is between the B+ (controller terminal) and motor, then it is motor current.

It would appear that the low voltage cutback (which you have set at 18V) is not entering into the mix. You would probably want to set that higher later on to actually protect your batteries, but leave it there for now.

That throttle up/down rate might enter into it. Now set at 15, maybe try 5.

Your tests show that the battery voltage is not tanking (dropping way low) on high current demand. And that you actually did see 400A, which I suspect, was motor current. 

You say you did see another 10 mph after bringing back two of the batteries from a near death experience. I would continue to monitor the batteries. Usually, once a bad battery, always a bad battery. Although you might get it to stay up for a few miles per charge to gauge performance. 

With you present system, 400A and 110V (under load), you'll never be over about 40-45 hp to the wheels and more likely 30-35. You should be able to select a gear to get you up in the 50 to 60 mph range, but will take a long time to accelerate up to that.

That's my take on it 

major


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## gt40ev (Nov 15, 2010)

Major,

I was talking to a couple of local guys and they both seem to think my batteries and controller should be fine, but that the 6.7 inch motor is my problem. They both seem to think that an 11 inch Kostov would have me shredding tires.

Would you agree?


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## major (Apr 4, 2008)

gt40ev said:


> Major,
> 
> I was talking to a couple of local guys and they both seem to think my batteries and controller should be fine, but that the 6.7 inch motor is my problem. They both seem to think that an 11 inch Kostov would have me shredding tires.
> 
> Would you agree?


The bigger motor will give you more torque for a given current. So at the 400 amp limit (on the controller) that additional torque may well be able to smoke tires. But you do have a 4 or 5 speed tranny, right? So, big deal.

The larger motor is not going to give you more power (maybe a little due to increased efficiency). The power is set by the controller (and battery voltage). The larger motor would allow you to run at high power for longer without overheating the motor. But, although you never stated your battery Ah, you may not have enough battery to run long enough to worry about that.

Now take that 11 inch motor and put an 800 or 1000 amp controller with it and a battery good enough to feed it, and yes, now you're talkin' 

major


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## Bags (Jun 20, 2010)

major said:


> Now take that 11 inch motor and put an 800 or 1000 amp controller with it and a battery good enough to feed it, and yes, now you're talkin'
> major


And I think that's the advice that everyone has been avoiding. Replacing these three components is essentially the "starting over" that you didn't want to do.


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## cruisin (Jun 3, 2009)

My suggestion would be to get a AC-50 (your cost $4100) which will include a 500w Curtis controller. A added feature would be the programmable option of the controler unlike anyother. Re-gen is nice if you plan on doing city driving. Cant have it with a brushed DC. For info on the AC-50 email me at [email protected]


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## Qer (May 7, 2008)

gt40ev said:


> I was talking to a couple of local guys and they both seem to think my batteries and controller should be fine, but that the 6.7 inch motor is my problem. They both seem to think that an 11 inch Kostov would have me shredding tires.


I decided before not to get actively involved in this thread to not risk being accused badmouthing a competitor or just trying to sell you my own products, but to heck with that! I see that crusin has already passed that ethic line with a sonic boom, so whatever I say can't possibly be more questionable. 

The motor is not your problem. The only things the motor can do is converting electrical power to mechanical power (+ heat, of course) or blow up trying. Replacing the motor will, as Major told you, not give you more power, only change the "gearing" between RPM and torque.

You have two weak components in your setup and that's the batteries and the controller. Your controller is only able to generate roughly 50 HP peak and given what I've heard and seen about Kellys I wouldn't be surprised if that drops to maybe 20 HP when the controller starts to heat up. That's pre-WWII Beetle performance...

Replacing the controller with something that can provide some real power (or even just with one that could provide you with 400 CONTINUOUS Amps..) will definitely make your car faster and funnier to drive, but even a serious high power controller can't give you high power if the pack's not able to provide it. Since you only see a sag to 110 Volt even at full throttle my guess is that the pack is in such a good shape that it's not that that is your real bottle neck here (even though a higher pack voltage probably wouldn't hurt...).

A better controller will definitely give you more torque at red lights and from what I can understand from this thread the pack is capable of providing more power than is used today so your top speed should also improve, but if you get a better controller there's always the question what will be the next bottle neck. If it's the batteries a good controller will let you add safe limitations to avoid damaging the pack and you'll at least have full pack power at your disposal. If it's the motor that's the next bottle neck life will be a bit more, err, interesting since a bigger controller could blow your motor...

One thing's for sure; replacing only the motor won't get you anywhere. At least not faster than today.


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## Tesseract (Sep 27, 2008)

gt40ev said:


> My shunt is between the contactor and the motor. Is that motor current or battery current?


The contactor should be between battery and controller. The shunt could be between contactor and controller (battery current) or the controller and the motor (motor current). 



gt40ev said:


> The settings on the controller are:
> 
> Foot switch: disabled
> Throttle effective start: 10%
> ...


I haven't seen a Kelly interface in a long time, but the setting I changed to red is wrong for an EV. You want to change it to, I believe, "torque" or "balanced". If you move the shunt over to the battery side I bet you'll never see it hit 400A. Keep in mind that the total power is delivered is determined by measuring the current and voltage on the same side of the controller, either battery or motor. So, battery current x battery voltage = total power... The maximum you can get from this controller, assuming the batteries don't sag (not realistic, of course) is 120 x 400 = 48kW, or ~64hp.

The Curtis AC controllers are really nice units, but the AC-50 combo might not feel any more powerful than what you already have.

The sag from your pack doesn't look too bad, so I'm guessing that you are measuring motor current - if you were pulling 400A from your lead-acid pack it would probably sag down to around 90V, rather than the 110 you saw.

That 6.7" motor is, in my opinion, a bit too small for an on-road vehicle. I didn't see how much your EV weighs, but if it's based on a VW chassis then it's probably fairly light so maybe change to an 8" NetGain or a 9" Kostov motor?


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## EVfun (Mar 14, 2010)

Qer said:


> The motor is not your problem. The only things the motor can do is converting electrical power to mechanical power (+ heat, of course) or blow up trying. Replacing the motor will, as Major told you, not give you more power, only change the "gearing" between RPM and torque.
> 
> You have two weak components in your setup and that's the batteries and the controller. Your controller is only able to generate roughly 50 HP peak and given what I've heard and seen about Kellys I wouldn't be surprised if that drops to maybe 20 HP when the controller starts to heat up. That's pre-WWII Beetle performance...
> 
> ...


I want to agree (and disagree) with Qer. 

The controller is your weakest link. You have enough controller for about 48-50 horsepower if it actually delivers a full 400 amps. I'm betting your VW kit car is heavier than my VW kit car (see avatar.) The thing is, my old Curtis 1221b has a reputation for putting out all 400 amps for long enough to actually make 50 HP (provided the vehicle is not to heavy, the continuous rating is only 150 amps.) That is enough to fake sporty performance in a 1400 lb. car and get to freeway speed in about 15 seconds. The Kelly has a reputation for barely hitting the peak amp levels when stone cold so you may be peaking out at something even lower.

The motor in your conversion is only 65 lb. and has a small 7/8 inch output shaft. I'm confident it will be the next weakest link. To go past 50-60 HP I would like to see at least a larger 6.7 inch motor (something around 90 lb. with a 1-1/8 inch shaft) or preferably an 8 inch Advanced DC motor (or the Netgain Impulse 9, a shorter but fatter motor that is nearly equivalent.) I wouldn't recommend a larger motor, one that makes more torque per amp, with your lower pack voltage. You will have more peak torque but you will move the rpm range of the power band down to the point of not matching the VW transaxle gearing well. My buggy is running a Prestolite MTC 7.2 inch motor and I can overheat the Curtis controller long before I overheat the motor. 

You certainly don't need a controller that can put out 400 continuous amps unless you have a motor and batteries that can handle 400 continuous amps. That is at least 45 continuous horsepower. 400 amps will flatten an Optima battery in about 4 minutes. A motor with a 400 amp continuous rating will be about 300 lb.


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## Qer (May 7, 2008)

EVfun said:


> I want to agree (and disagree) with Qer.


I'm cool with that. 

So what would you say? A Curtis 1221 or 1231 instead of that Kelly would give a bit more acceptable performance in his car?


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## piotrsko (Dec 9, 2007)

my $.02: #1 weigh the car. drive over to some truck scales and spend about 10 bucks. You may get surprised. i'm guessing 1700 lbs or more. I don't recall those GT40's being fast with a 1600 dual port, just eye candy.

#2 replace the weak batteries. They ain't helping anything and you'd have to replace them anyway if you added more for higher voltage.

#3 BORROW one of your "friend's" controller if it has better demonstrated capacity. this eliminates the question of whether or not the motor is adequate. I myself would figure out how to bypass the in your car controller, but in fair warning: I have done tons of really stoopid stuff.

based on this cheaper info, you now have a baseline for what you want to change, fix, hotrod or whatever.

#4 seriously consider the advise that major, Tess, Qer, GottI, and EVfun provide.


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## EVfun (Mar 14, 2010)

"Acceptable" is such a vague word.  

I think a Curtis 1231C-7701 (120 volt, 550 amp) controller would pound that little motor as hard as I would dare. I think the performance would be more acceptable or at least not embarrassing. The motor is only rated for 72 volts, 9 HP continuous and 40 HP peak (of course we have never respected "peak" ratings.) I would be curious to see the battery current peaks while driving with the Kelly, but I would guess it warms up and limits to about 300 amps based on the voltage sag. Freeway driving with the small motor will still be limited, but the range is limited with the small pack anyway.

My choice would be a reconversion with an ADC 8 inch or Impulse 9 inch motor and a Soliton 1 or Zilla Z1k. Programmable controllers are nice and I prefer the silicon to not be the weakest link. I think either controller could be set to destroy the little motor currently installed and in my desire to have fun I would most likely "go there" at some point.


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## Qer (May 7, 2008)

EVfun said:


> My choice would be a reconversion with an ADC 8 inch or Impulse 9 inch motor and a Soliton 1...


Flatterer! 

However, Jr should be more than enough, don't you think?

Anyway, now we're slowly starting to hijack the thread...


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## EVfun (Mar 14, 2010)

I thought the Jr was for motorcycles and go-carts. 

This vehicle is only a 120 volts, what is the Jr going to do that the cheap Curtis 1231C cannot do? I know you have valuable features, but at lower voltages still about 60 HP.

I see a bit of a dilemma, the power can only be turned up a little right now because to much will be really hard on the small motor. With more motor the options expand, in the usual cubic dollars sort of way. More motor, more controller, more battery pack, repeat until broke. With the lower pack voltage I would consider the 160 volt WarP drive as a budget way to pass 1000 motor amps, but I don't know enough about the features and support to recommend the controller. This was the land for the budget Z1k-LV, but it is no longer available.

I've had a few questions about the EVentics controllers but I'll take those to the Jr thread.


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## Qer (May 7, 2008)

EVfun said:


> This vehicle is only a 120 volts, what is the Jr going to do that the cheap Curtis 1231C cannot do?


Being more future proof considering the wider voltage operation area? 

No, I concur. A Curtis is probably a very good choice, especially considering this project apparently already is over budget...


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## Tesseract (Sep 27, 2008)

EVfun said:


> I thought the Jr was for motorcycles and go-carts.


Vehicles under 2500lbs, more or less. It's hard to really take advantage of the torque capability of a 1000A controller in a sub-2000lb vehicle unless you have specialized tires - there just isn't enough traction available.



EVfun said:


> This vehicle is only a 120 volts, what is the Jr going to do that the cheap Curtis 1231C cannot do? I know you have valuable features, but at lower voltages still about 60 HP.


I'm really trying to avoid the sales pitch here, but if the only metric you use to compare controllers is the "peak" power rating, then I guess you have a point - sort of analogous to only comparing ICE vehicles on the basis of their engine displacement. 

Keeping the above caveat on sales pitches in mind, one major advantage of the Soliton Jr. over its peers is its much greater ability to shed heat. If you look at the datasheet for the 1231C it shows that the voltage drop at 100A is 0.3V. Since MOSFETs behave like resistors when on, the loss at 500A will be 1.5V (with a strong positive tempco, doubling, in fact, with a 75C rise). IGBTs follow the diode equation, so the on drop increases 60mV for every 10x rise in current. The on drop of the IGBTs we use is 1.45V at 500A, so slightly _less_ than the MOSFET-based Curtis, and the positive tempco is much lower - increasing to just 1.60V with a 75C rise - so the controller with the better cooling here will deliver more overall power, and that would be our's.



EVfun said:


> I see a bit of a dilemma, the power can only be turned up a little right now because to much will be really hard on the small motor. With more motor the options expand, in the usual cubic dollars sort of way. More motor, more controller, more battery pack, repeat until broke.


I like that - cubic dollars is right! 

But yeah, the OP's current controller and motor are well-suited to each other, just not to the vehicle they are installed in... Any improvement in performance will require upgrading both, and unless some fortuitous scrounging of the forklift yards turns up a motor, the price tag for this upgrade will likely be around $3000 depending on the exact components chosen.


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## major (Apr 4, 2008)

Sometimes we get a couple of threads talking about the same thing, like this one: http://www.diyelectriccar.com/forums/showthread.php?p=213010 Ziggy (post #3) says he can do 70 mph with 120V of cheap batteries and a D&D (the longer model). He doesn't say what controller he uses, size of his car or how long it takes to accelerate.


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## GerhardRP (Nov 17, 2009)

Sound like some progress.
Googling around, I found a discussion of gt40s. Post #22 of this thread:
http://www.gt40s.com/forum/gt40-tech-exterior-interior-ac-trim/24783-cda-gt40-calculate-your-optimal-gearing-2.html
indicates that this car should require about 7kW to maintain 100km/hr. That is within the rating of the motor. [barely.] And easily within battery and controller capacity. 
I looked back in this thread and don't see your actual top speed. 
Maybe it is time to start to look at other parasitic losses: after a drive go around and feel things to find out what is hot..brakes, transmission, tire surfaces etc.
You might also do a "coast down" from your top speed with the car in neutral on level gound. A tracking GPS is the easiest way, but a passenger with a stopwatch and paper will work too. You will need to know the total mass as driven.
Gerhard


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## JRP3 (Mar 7, 2008)

cruisin said:


> My suggestion would be to get a AC-50 (your cost $4100) which will include a 500w Curtis controller. A added feature would be the programmable option of the controler unlike anyother.


Yes it's a nice feature, too bad it doesn't come with the necessary components that allow you to do it. Slap another almost $500 on the purchase price to get the hand held programmer or Programming station software


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## EVfun (Mar 14, 2010)

I replied to Tesserect (post #26 in this thread) over here to avoid hijacking this thread.


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## piotrsko (Dec 9, 2007)

GerhardRP said:


> Sound like some progress.
> Googling around, I found a discussion of gt40s. Post #22 of this thread:
> http://www.gt40s.com/forum/gt40-tech-exterior-interior-ac-trim/24783-cda-gt40-calculate-your-optimal-gearing-2.html
> indicates that this car should require about 7kW to maintain 100km/hr. That is within the rating of the motor. [barely.] And easily within battery and controller capacity.
> ...



UUUhh, I believe the OP said it was a VW kit car. However all other things being fairly equal, yes the cd's and etc from that forum are appropriate. plug that into the spreadsheet over on http://www.curiousexistence.com/sites/default/files/VehicleEfficiencies.xlsx


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## gt40ev (Nov 15, 2010)

What's a Soliton Jr? 

I was considering building my own controller with the Cougar Open ReVolt and either Paul's Mosfet design or adapt it to IGBT.

Any opinions about the Mars Electric ME1002? It claims better performance than the Warp 9 and ADC FB4001. Do you believe it?

Lastly, I found room for 2 more batteries. It'll take a new rack behind the seats but would give me 144 volts. The Kelly would definitely have to go (it complains now when the pack is at 100%) but I'm getting the message from all concerned that I grossly under engineered this project.


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## Duncan (Dec 8, 2008)

Hi GT40
I gather that you are on a tight budget, 
I managed to get a nice 11 inch motor for $100

I would suggest 
(1) Read the using a forklift motor thread
(2) Find out who locally repairs forklifts - I found two companies in our local big city
(Invercargill - 50,000 people)
(3) drive over and see them with a handfull of dollars
An old motor is only worth scrap money to them

If you get a nice motor - sell off your current one - you may make a profit!

Controllers - 
I have ordered the OpenRevolt kit- as I am a complete novice at electronics it may take me some time to get it working!

That MARS unit sounds nice but $100 sounds nicer to me!
(did I mention I am a Scotsman?)


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## Qer (May 7, 2008)

gt40ev said:


> What's a Soliton Jr?


http://www.diyelectriccar.com/forums/showthread.php/soliton-juniors-first-scream-52093.html

Air or water cooled 500 Amps continuous rating (with water cooling) controller with 9-342 Volt input range. Essentially exactly the same as Soliton 1, but with lower motor current.


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## JRP3 (Mar 7, 2008)

gt40ev said:


> Any opinions about the Mars Electric ME1002? It claims better performance than the Warp 9 and ADC FB4001. Do you believe it?


No I don't. Do they provide a performance graph?


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## GerhardRP (Nov 17, 2009)

JRP3 said:


> No I don't. Do they provide a performance graph?


 http://lib.store.yahoo.net/lib/yhst-57437235823410/ME1002DATA.pdf


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## JRP3 (Mar 7, 2008)

GerhardRP said:


> http://lib.store.yahoo.net/lib/yhst-57437235823410/ME1002DATA.pdf


Pretty close http://www.go-ev.com/images/003_16_WarP_9_SpreadSheet.jpg


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## gt40ev (Nov 15, 2010)

I have one of these ME1002 motors on it's way to me. I'm going to attack this by cost, the motor first (yes, I got a great deal on this 10 inch motor). If that doesn't do it, then I'll build a Cougar and add more batteries (144V 500A). If that doesn't do it, then toss the think EV batteries and switch to lithium.

I'll keep you updated as I go.

Thanks for all the help.


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## brainzel (Jun 15, 2009)

get40EV seems to be satisfied at the moment and will test his new motor ;-)
So perhaps I can fill the upcoming silence with my personal problem, which is good shaping to the headline 

2820 lbs (1280kg) Car
D&D ES-31B - 6.7" diameter
122Volt LiFePo4 (120AH)
Curtis 1221C 120V/400A
65mph (105km/h) maximum speed
50 mph (80km/h) comfort speed

The performance is "OK", but not realy a good acceleration :-/
Would a controller change bring my an Improvement or where is my bottleneck?


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## major (Apr 4, 2008)

brainzel said:


> 2820 lbs (1280kg) Car
> D&D ES-31B - 6.7" diameter
> 122Volt LiFePo4 (120AH)
> Curtis 1221C 120V/400A
> ...


Sure, brain, a bigger controller will get you faster acceleration. Now you're limited to 400A. Go to a 600A controller and you should see 50% more motor torque and therefore 50% better acceleration.

The motor will likely tolerate the increase in current. I'd keep an eye on commutation and heat. The battery will see increased current if you accelerate up to base speed in each gear. 400A is 3.33C, but 600A is 5C. Those cells will do that much, but you need to watch that you may exceed manufacturer's recommended discharge rates. So you can always watch your battery ammeter and shift gears to keep battery current below 400 and still enjoy higher motor current with the bigger controller. This means the motor will be running slower during your accelerations, so watch motor heat, especially if it is just self ventilated with its internal fan.

Regards,

major


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## brainzel (Jun 15, 2009)

Thank you Major.
Like your advise, I don't want more than a maximum of 500A going out of the battaries.
These are the SE120AHA (130Ah) so 4C for a short period of time would be no problem, but I don't want to strain them too much.

I found a thread here about the wiring of the Curtis (plug breaking / A2 discussion) and get reminded, that I wired the A2 too but do not use plug breaking.

Could it be a adjustment or wiring thing?
How do I have to adjust the Curtis to get the best performance to my motor?

Michael


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## major (Apr 4, 2008)

brainzel said:


> How do I have to adjust the Curtis to get the best performance to my motor?


Crank it up to 11 

I don't know where it is set now. Do you have meters in the car? You can somehow take a baseline and make adjustments and see improvement, or not. Try to mark your starting points so you can return to that if needed.

As far as plugging......if you don't have reversing contactors, you can't really plug. Well, I guess you could if you shifted into reverse while traveling forward. Which is a good reason to leave A2 connected, IMO. Just in case you roll backwards and give it a forward run command.

BTW, if you do crank it up to 11, watch the controller heat. More current, more heat. Got a heat sink and fan?

major


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## brainzel (Jun 15, 2009)

major said:


> Crank it up to 11


This must be an american saying, isn't it? Sorry, I don't understand the meening of it 



major said:


> Do you have meters in the car?


Sure. Battery current, voltage, ampmeter (Link 10).



major said:


> As far as plugging......if you don't have reversing contactors, you can't really plug. Well, I guess you could if you shifted into reverse while traveling forward. Which is a good reason to leave A2 connected, IMO. Just in case you roll backwards and give it a forward run command.


No reversing contactors.
I think I don't realy need that plug breake, but the wiring diagramm from Curtis shows the connection of the A2. That's the only reason I have wired it 
You can't shift to rear gear while running forward in a newer Volkswagen.
There is a mechanical barrier built in, so from that point I don't need it.



major said:


> Got a heat sink and fan?


Not yet. There is no noteworthy heat at the moment.

So to the adjustment:
plug brake (left) fully screwing left, while not needed
current limit (middle) fully left, while controller will cut of at 400A
accelleration (right) fully right, to feel the maximum
Looking at the meters and adjust if needed.
This seems to be a plan or not?


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## major (Apr 4, 2008)

brainzel said:


> So to the adjustment:
> plug brake (left) fully screwing left, while not needed
> current limit (middle) fully left, while controller will cut of at 400A
> accelleration (right) fully right, to feel the maximum
> ...


Hi brainzel,

I'd leave the plug adjuster alone.

Both current limit and accel adjusters fully CW for the max, per that diagram.












> This must be an american saying, isn't it? Sorry, I don't understand the meening of it


Just from a funny movie scene. Volume adjustment knobs on guitar amps are calibrated 0 to 10. This rocker had his amp which went 0 to 11  British movie, I think.

Regards,

major


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## Tesseract (Sep 27, 2008)

major said:


> Just from a funny movie scene. Volume adjustment knobs on guitar amps are calibrated 0 to 10. This rocker had his amp which went 0 to 11  British movie, I think.



This is Spinal Tap!

http://www.imdb.com/title/tt0088258/


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## JRP3 (Mar 7, 2008)




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## major (Apr 4, 2008)

Tesseract said:


> This is Spinal Tap!
> 
> http://www.imdb.com/title/tt0088258/


Yeah, and I see it was rated 8 out of 11 stars


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## EV-propulsion.com (Jun 1, 2009)

Just want to add what a Curtis engineer wrote me about the A2 and plug braking quite a while ago....
"

Although the controller manual shows an A2 connection between the controller and motor, this connection should not be included. Plug braking on the 1231C at high voltages is not stable. Even if it were stable, plug braking while driving on a road is a dangerous maneuver. Reverse should be handled via the vehicle’s transmission. The manual has been in need of an update for years."
  In other words, don't connect it !

 Mike
 www.EV-propulsion.com


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## gt40ev (Nov 15, 2010)

Well, I'm back. 

I found another local builder who wanted to experiment so he took the D&D motor, and the wilderness EV coupler and adapter off my hands. 

I picked up a transmission jack scissor lift from Harbor Freight so I could handle the 200 lb Mars Electric 10 inch ME1002. The geometry was completely different but using the lift to hold the motor in position, I was able to ascertain that the face of the motor was exactly 1.75 inches from the face of the VW transaxle when the tip of the shaft was lodged inside the recess of the motor shaft. 

So I got my hands on a slab of 7075 alumimum of this thickness 12 inches by 12 inches that I found on ebay for $84 plus shipping and drilled a 4 inch hole in the center (took 3 days to drill this with my hand held air drill) then another day to get the motor mount holes and transmission holes aligned to keep it all centered. Grade 8 3/8-16 hardware from Home Depot of various lengths (2-1/4 for the plate to motor and 3 of 4-1/4 and 1 of 6 inch for the plate to transaxle mounts) and it'll hold together.

For a coupler, I used the method I found at http://www.electric-lemon.com/?q=node/213. This consisted of a surplus gear from www.surpluscenter.com ($20) and a clutch disk from West Coast core ($27). I then drilled out the rivets, turned the hub over to center it over the hole in the gear and drilled and tapped 8 1/4-20 screw holes to bolt it all together. I actually only ended up with 7 screws because my tap broke on hole number 6. I couldn't get it out, so I left it as a key. If this turns out to be a problem, I'll get another gear and do it over again. There is a ridge on the back side of the clutch hub so I fashioned a bushing out of lexan to take up the space and offer a slight buffer to the metal on metal.

The whole assembly slipped on nicely and bolted right up.

Now for what I thought was the easy part. The motor has 4 terminals: A, F, AA, and FF. I presumed this would be analgous to A1, S1, A2, and S2 respectively so I jumped AA to FF with a piece of 1/4 copper bar and ran B+ to A and M- to F. This is the same configuration I see on every wiring diagram and worked great on the D&D (assuming F=S1, AA=A2, and FF=S2) so I expected the motor to turn clockwise. I ran the motor in neutral and it sounds good. I actually had some grinding sounds before that I thought were coming from the bearings in the transaxle, but those sounds went away with the new motor. I'm thinking the coupler/adapter wasn't aligned properly. Then I gritted my teeth and put it in reverse. Damn if it didn't go the wrong way. Put it in first, and I was rolling backwards out the garage. So I put it in reverse and pulled straight back into the garage.

Any clues on how to hook this up properly? I'll give Mars a call tomorrow and post their answer as to what the terminals mean and which cable should go where to make it turn clockwise.

I'd rather not remove the motor to take pictures, but I'll take some shots with the motor installed the best I can and post those, too.

Tom


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## major (Apr 4, 2008)

gt40ev said:


> so I jumped AA to FF


Hi Tom,

Guessed wrong  Jump AA to F or A to FF. It will rotate opposite direction.

major


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## gt40ev (Nov 15, 2010)

Major, you were right. I jumped A-FF and put B+ on AA and M- on F. Success! It goes forward! Tomorrow, we test drive and I'll report back if the motor solved my problems. I think there was some uncertainty about how this Mars Electric motor was going to perform. I'll find out tomorrow.

To summarize for anybody who is interested in how to hookup this ME1002 Mars Electric 10 inch motor:

AA-FF B+ on A and M- on F and this motor spins counterclockwise.
A-FF with B+ on AA and M- on F and it spins clockwise

Thanks for all your help. I will report back after my test drive.


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## major (Apr 4, 2008)

gt40ev said:


> Major, you were right. I jumped A-FF and put B+ on AA and M- on F. Success! It goes forward! Tomorrow, we test drive and I'll report back if the motor solved my problems. I think there was some uncertainty about how this Mars Electric motor was going to perform. I'll find out tomorrow.
> 
> To summarize for anybody who is interested in how to hookup this ME1002 Mrs Electric 10 inch motor:
> 
> ...


Hey gt,

I thought of something. Imagine that 

I don't know about that Mars motor. It is new on the scene. I suggest you check first, or take it easy on the test drive. It is unknown if it has a brush advance, and if so, for which direction of rotation. If it is advanced for opposite than which you run, you could damage the commutator with hard use. Or even if it is set on neutral brush position, damage it from high voltage, high current and high RPM. 

Can you check with the place where you bought it?

Regards,

major


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## gt40ev (Nov 15, 2010)

So far, so good. Pulls with good power up the hill with the ME1002 Mars motor. I can go up the hill now in second gear and pulls about 200 amps at 80-90 volts. I don't know the speed because my speedo is not calibrated properly (another project for another day). The motor seems to be doing fine. I'm not sure what to look for with the brush advance issue, but the pace and power seemed ok. There's only so much I can do at 120 volts and I can't seem to send more than 200 amps. I think the controller is my next issue.

I drove around for about 6 miles up and down the hill (about 1/4 mile at 10% grade - you're breathless with burning thighs if you walk it) and some flat and after my 4th trip up the hill, it got sluggish to the point that I could not give more than 1/4 throttle without the Kelly cutting all power. Is that the controller overheating? I have more than 80% state of charge and the voltmeter still shows 120 volts at rest, so I think have plenty of battery left. I ran into this before but figured it was something else to deal with after I got it going the speed that I was comfortable with.

I managed to limp home at about 2 MPH backing the throttle off everytime the volts went to zero (which they did when I gave it too much throttle).

I put the charger on it and it took a charge for about 30 minutes before the charger reported the battery was full - I'm thinking it's the controller.

What do you think?


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## JRP3 (Mar 7, 2008)

If your voltage went to zero then either the batteries are toast or the charger isn't charging them, or both.


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## nimblemotors (Oct 1, 2010)

controller overheating is most likely the problem, can you gauge its temperature? too hot to touch? great to hear the motor helped, I've seen that Mars motor and wondered if its any good, always good to see competing sources. The previous motor was too small, but I think the controller is the real issue and the batteries not far behind.



gt40ev said:


> So far, so good. Pulls with good power up the hill with the ME1002 Mars motor. I can go up the hill now in second gear and pulls about 200 amps at 80-90 volts. I don't know the speed because my speedo is not calibrated properly (another project for another day). The motor seems to be doing fine. I'm not sure what to look for with the brush advance issue, but the pace and power seemed ok. There's only so much I can do at 120 volts and I can't seem to send more than 200 amps. I think the controller is my next issue.
> 
> I drove around for about 6 miles up and down the hill (about 1/4 mile at 10% grade - your breathless with burning thighs if you walk it) and some flat and after my 4th trip up the hill, it got sluggish to the point that I could not give more than 1/4 throttle without the Kelly cutting all power. Is that the controller overheating? I have more than 80% state of charge and the voltmeter still shows 120 volts at rest, so I think have plenty of battery left. I ran into this before but figured it was something else to deal with after I got it going the speed that I was comfortable with.
> 
> ...


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## gt40ev (Nov 15, 2010)

I recharged the pack and load tested each battery. I have one dead battery that's causing all my grief now. The kelly is probably fine, but could do better. I think the next step is batteries. I admin I bought used batteries as I continued to experiment and I've gone round and round with these replacing dead ones as I continue to test. I think to date, I've exchanged 5 of the original 10 that I purchased, so it's probably time to consider a new pack. I'd like to go lithium but the spousal budget committee is already having a cow over this project.


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## gt40ev (Nov 15, 2010)

Replaced the dead Think battery with a walmart Everstart Deep Cycle 125Ah. It's nice not getting stuck doing the 1mph crawl.

I'm still looking for that grin making performance so I'm shifting my focus to the controller now. Any thoughts on the EP-1000 or EV-1000? It's advertised capabilities look like they rival the Zilla 1K, but I've never heard of them before.


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## major (Apr 4, 2008)

gt40ev said:


> ....but I've never heard of them before.


That might be a clue  Can you post a link or vendor's site? I've never heard of them either.


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