# BMW Isetta conversion - which components



## todayican (Jul 31, 2008)

I would say the best bang for your buck with something that weight and speed would be a mars 1003 and an alltrax 7245 controller or 7234 (a bit slower)

Batteries are a huge question mark, how tight a budget are you under?


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## martin300 (Nov 1, 2010)

todayican said:


> I would say the best bang for your buck with something that weight and speed would be a mars 1003 and an alltrax 7245 controller or 7234 (a bit slower)
> 
> Batteries are a huge question mark, how tight a budget are you under?




I think 2000 to 2500$ are OK for batteries. Big problem is the max. axle-load so battery weight should be under 70kg (if engine is max. 15kg).

thanks
Martin


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## LuisM (Jan 18, 2010)

martin300 said:


> Hi,
> 
> I have an old BMw Isetta (355kg with 11hp).
> 
> ...


A Mars would be good for you. Please do a little research and find a motor with more or less the same torque (or less than two times) for the tiny engine. Otherwise your tranny would be damaged soon. 

Or... go direct drive. Two scooter hub motors would fit perfect for you. Kelly have some kits including almost everything you need. And lithiums is a must for you. Is not a huge pack, so, not so expensive, but it has to be as light as possible, due to the car. 

Have a look: http://kellycontroller.com/dual-keb-72v-8kw-regen-kit-p-360.html

Greetings from Spain,

Luis


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## todayican (Jul 31, 2008)

Thats going to be a toughie to get in under 2500 just for the components and battery:

http://cgi.ebay.com/EMC-RT-72v-Elec...ltDomain_0&hash=item3a5c6be213#ht_2757wt_1091

Thats most of the drive system, 

If you go Lifepo4, the batts would cost that alone. Lead would be a lot cheaper in the short term. 

for the amp draw, id say to stick with at least 90ah in thundersky type batteries, your range would be a bit more then your looking for, never a bad thing 

If you wanted to save just a few bucks you might could go with less of a more expensive battery, the headway 10ah. if you did 50ah total x 72v you would be ok for your range, I believe


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## drivin98 (May 9, 2008)

todayican said:


> Thats going to be a toughie to get in under 2500 just for the components and battery...


He said $2,000 - $2,500 for the batteries only.

Anyhow...if you went with 40 ah CALB lithiums, you'd need 21 to reach 72 volts. That's under $1,200 and about 69.5 lbs. I think that's about 6 kilowatt-hours. (I would check all my figures as I am pretty noobie about all this)

Range is very speed dependent so those more knowledgeable might chime in on whether more would be needed.


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## aeroscott (Jan 5, 2008)

they handle weight better then one would think , we had one with me on the shelf , mom dad and sister in the seat ( I was 10 ) . It has a chain drive to a 1 piece axle ( no diff on it ) would be easy for direct drive . should make a great ev .


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## martin300 (Nov 1, 2010)

I will get "my" Isetta (reversed trike, I have the three wheel version) on friday this week. I have seen it before with some rust on the body (some holes), and some missing parts (i can get without problems). BUT also the engine is missing so my idea was to convert this little car to an EV (without destroying the car: some modification on the floor-plate for the batteries is OK).

I am an electrican and also welding is no problem for me so I think I can do the restauration job alone. But i need help with the electronics and I also do not know if I will need the transmission (gearbox) in my little car )or direct drive with e-motor?).

I will go to my local car test-center to inform me about laws and regulations (voltage level and EMV testing, ...) here in Austria. I am sure there is some knowledge about this topic in this forum.

I want to check if there is a reasonable way to convert my Isetta to an EV (and of course there is also a limited budget an appr. 3600$ overall).
I post some photos when my Isetta arrives and I will start with the restauration job.


I have to thank you in advance for your help.

best regards from Austria
Martin


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## martin300 (Nov 1, 2010)

Hi,

I started with restoration now. Quite lot to do (cleaning frame, many parts to rebuild , ..).

I also want to start to think about the components in detail:

*Targets:*
- budget: max. 4000 USD
- range: min. 35 miles
- speed: min. 45 mi(h
- add. weight: 110kg (motor, batt., contr.)

tech. data Isetta 300 export(3-wheeler):
please see attached table (sorry it is in german)

I have attached also some photos ...
Also one photo I found from conversion.

*My big questions:*
- do I need the original transmission (is it easier to finish the conversion with transmission)?
- if no transmission needed, what about gearreduction in chain case (now 2,3:1)?
- components: I live in Europe (favor to parts I can buy here)
- motor: Perm PM120l or Lynch (Agni 95s) or...??
- controller ??
- batterie: biggest question: Li Batteries for sure but *??? Voltage, Ah ???*


thanks for your help
best regards
Martin


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## Duxuk (Jul 11, 2009)

My Kirk EV aka. Sparky weighs 330Kg including 125Kg of LA @72V. I use a Mars 0709 but need to keep the max amps down to 210 to prevent it burning the brushes. I have an Alltrax 7234 so controlling things is easy. Your weight would be too much for my motor, I think by the time you had fitted batteries but if you talk to John Fiorenza at Mars he is very helpful. My performance meanwhile is 56 mph! Acceleration is slow off the mark, especially up hill, but OK above walking pace.Range wise I think you would struggle to acheive your target for long term use with FLA. You just won't be able to pack in enough lead, particularly as you have a smallish weight limit.
Of course I could sacrifice top speed for better acceleration, myself, but the range would still be an issue. When I first put it on the road last summer I could get >25 miles, but at too great a cost to mt FLA pack.
Lithium or NiMh? Vectrix seem to do OK with NiMh but I think that the trick is a very good BMS in that case.
Incidently, I use a direct drive-no transmission. It save weight, money, complexity and space. Your greater weight should still be OK without transmission because you speed requirement isn't so high.

Andrew


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## martin300 (Nov 1, 2010)

*Re: BMW Isetta conversion - components*

i think for my project it is a must to go with Li Batt.

please help with my *big questions* (thread #9)
http://www.diyelectriccar.com/forums/showpost.php?p=222846&postcount=9 

thanks 
br
Martin


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## Duxuk (Jul 11, 2009)

If I were in your position I would look on the Electric Motorsport website. They have details of the EMC-RT200 motor from Mars. It is capable of 200Amps continuous which would be plenty for your conversion. The best news is that the cost is only $650. Electric Motorsport can supply a kit with controller, wiring, contactor, charger DC-DC converter, fuses etc.
I'm sure that you could source the parts cheaper, but I got everything except the battery side of things from them so that it all came as one package. It is easier to import this way. You only need to pay one payment for import duty. This part is not difficult at all, so please don't feel that you need to buy from a European based supplier.
There are other US based companies who could supply a similar package, so it may be worth looking around on the internet.
EMS now supply Lithium batteries also, which they did not yet have 2 years ago when I was buying, so you could always Email them or even phone them with your requirements.
I would imagine that you are going to need about 200Wh/mile of energy. That means you will need about 10KWh of battery to have a maximum theoretical range of 50 miles. Of course you would only ever use 80% max. of this storage. Still you might be able to do 40 miles.
I am not thinking of upgrading to Litium but if I was I would be prepared to invest a lot in a BMS to protect my investment in batteries. (The thread on this subject in the batteries section is one of the hottest topics of debate!)
$4000 may be a liitle tight to get everything you need.

I think I said above that I would be happy to use direct drive because of your low speed requirement. Transmissions are heavy. I use a 530 motorcycle chain with sengine sprocket from EMS (12 tooth) and a specially made wheel sprocket (46 tooth) for my 24 inch Kawasaki rear wheel. The EMS website will tell you how many rpm per volt you will get. I calculated 60mph @ 72V. This figure was avery good guess, since a full throttle I get voltage drop., hence only 56mph.


My lighter trike uses about 140Wh/mile unless you go very slowly. That is a figure based on experience, not conjecture, so I hope it is helpful.

Keep us informed about your project. I love reverse trike and think your Isetta is a very good choice for conversion. A Mescerschmitt (think my spelling is wrong!) might be even better because you have the rear seat area as an ideal battery compartment, though you would maybe need a ventilated battery box in there.

Andrew.


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## martin300 (Nov 1, 2010)

*Re: BMW Isetta conversion - components*



martin300 said:


> i think for my project it is a must to go with Li Batt.
> 
> please help with my *big questions* (thread #9)
> http://www.diyelectriccar.com/forums/showpost.php?p=222846&postcount=9
> ...




please help!!!
Any suggestions for the components (details) I will need??

THANKS
br
Martin


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## MalcolmB (Jun 10, 2008)

Here's one fairly simple setup.

Since your max speed is only 40 mph I would estimate energy consumption at 120 Wh/mile. (That's 1.5 times the energy consumption of my motorbike if I average 25 mph).

To get a 30 mile range that means your total energy requirement is 3.6 kWh. To give a decent safety margin I would round that up to 5 kWh.

The simplest setup would be 16 x 100 Ah CALB or Thundersky lithium cells for a total pack voltage of just over 50V and weight of 50 kg.

Combine this with an Agni 95 motor and Alltrax 7245 controller. Both are reliable and relatively easy to install.

I don't know the diameter of the rear wheels, but as a rough guess you would need a gear ratio of around 6:1. It doesn't look as if that can be achieved in a single stage using the existing chain case (not enough room for the large sprocket). You may need to do a two-stage chain reduction. You already have the final stage, so you just need to fit a sprocket to the existing input on the chain case and drive this with the Agni (chain drive) to give a first stage reduction of about 3:1.

Total additional weight would be around 70 kg, less the weight of the original engine.

This is the simplest/lightest setup I can see. For higher top speed and better acceleration close to your top speed it would be worth considering higher voltage: 60 to 80V. However this would mean increased battery weight/complexity. You could still use the same motor and controller though.

There's a useful section in the FAQ on the Agni site, under the heading "Is the motor suitable for my vehicle?": http://www.agnimotors.com/home/index.php?option=com_content&task=view&id=31&Itemid=67


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## Duxuk (Jul 11, 2009)

MalcolmB,
I disagree with your energy requirement estmate. If a builder underestimates the energy consumption, they will end up with a White Elephant, that is something which cost a lot but does not acheive their goals. My trike needs 140Wh/mile to acheive the performance goals, yet it's frontal area is rather less. (Who knows about drag coefficient?). With my lower weight I would therefore stand by my 200Wh/mile estimate.
I agree with your choice of controller but I would not spend the extra money required for an Agni motor or a Lynch. I would definately go for a Mars for $650.


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## MalcolmB (Jun 10, 2008)

Hi Duxuk,
My figure does appear low, but it was partly based on the fuel consumption of the original Isetta, which was over 80 mpg. 

Even though your trike has a smaller frontal area, I'd be willing to bet that the CdA of the bubblecar is lower than your trike's, since it has a much more slippery shape. I also added a healthy safety margin to my initial energy figure. 200 Wh/mile is what I would expect for an efficient small car (Mini/Fiat 126 etc) conversion at maximum speed of 40 mph.

I definitely don't want to give anyone an over-optimistic picture, but likewise feel it's important not to be over-cautious as that could discourage someone totally.

Malcolm


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## martin300 (Nov 1, 2010)

martin300 said:


> Hi,
> *Targets:*
> - budget: max. 4000 USD
> - range: min. 35 miles
> ...


Isetta should take extra load (2 persons) of 160kg (350lbs)
- range: minimum 35 miles
- speed: minimum 45 mph

see below technical specification of Isetta 300 (also drag coefficient):

thanks for your setup suggestions


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## MalcolmB (Jun 10, 2008)

OK, so you changed your original requirements Martin. In that case energy requirements will naturally be higher, somewhere between my estimate and that of Duxuk.


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## martin300 (Nov 1, 2010)

MalcolmB said:


> OK, so you changed your original requirements Martin. In that case energy requirements will naturally be higher, somewhere between my estimate and that of Duxuk.


Hi MalcomB,

yes your right the numbers are different from 1st posting (because of my conversion error).

you wrote:
_You already have the final stage, so you just need to fit a sprocket to the existing input on the chain case and drive this with the Agni (chain drive) to give a first stage reduction of about 3:1.

_please, can you give me some more details to understand this?

What do you think now for the final suggestion for components?

THANKS al lot for your Help (and for your patience)!!!!


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## MalcolmB (Jun 10, 2008)

Sorry Duxuk, I didn't notice that the desired range and speed had gone up. My figures were based on the original 30 miles and max 40 mph. Increasing those to a minimum of 35 miles and minimum 45 mph makes a considerable difference. The energy consumption is likely to be somewhere between 150 and your figure of 200 Wh/mile, depending on the passenger load.

Martin
This can certainly be done but it's likely to be more expensive than you hoped. The solution I've given here is the minimum you're likely to need to meet your goals. If you want a greater safety margin you should consider going to larger cells (130 Ah).

You can still use the same motor and controller. The cheapest and simplest battery solution is still to use the Thundersky/CALB 100 Ah. You can use up to 26 cells and still stay within the voltage range of the Alltrax 7245 (90V). I would buy 26 cells but just fit 24 in the Isetta (if you can find space). Keep the remaining two cells as spares or to add to the pack in case your range is not quite sufficient.

It's hard to see details from your photos, but it looks to me as if there is a rubber coupling between the engine and the chaincase/swingarm. Is it possible to remove the engine, drive shaft and rubber coupling, then mount a chain sprocket in place of the rubber coupling? You could then mount the motor a short distance away, with a chain drive to this new sprocket.


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## martin300 (Nov 1, 2010)

THANKS for your very helpful information....

motor: is there a big difference of the suggested Lynch (Agni) or the Mars motor? Where do i get this two motors in Europe?

What do you think about the PMS 120l or 150l from PERM (see tech. Spec. as pdf).


Anybody knows where to buy the batteries (Thundersky) in Europe?

Any suggestions for additional parts I will need (BMS, charger, throttle, ...).

THANKS again

br
Martin


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## Duxuk (Jul 11, 2009)

Hi Martin 300,
for Lithium batteries in Europe you could try GWL Power who have an advertisement in the side bar to the right of the thread! Their prices look good, are in Euros and the company is based in Prague. They have 4 cells of 60Ah in a convenient block of about the size of my own FLA batteries. I could do a simple swap if I had the money! These nominal 12V LiFePo batteries (12.8V) when charged) do not come with any battery management as standard.Many do not think it is neccessary anyway, but if you intend to discharge the batteries deeply then I would think it is required.
The Mars 1003 motor would be the best choice of their range. It is brushed, that it is has carbon brushes which contractg the commutator, and permanent rather than electro magnets. It can give 11.5Kw (>15 Bhp) continuously or up to 23 Kw for a short time. I don't know of a European distributor but as I mentioned before, it is not difficult to import from the US. Electric Motorsport are the only company that I have dealt with and they were very helpful. They can also supply Alltrax controllers, which would be a good choice, I think. You can certainly buy Alltrax in Europe. There is a supplier in England who's prices were very good. However, I think Electric Motorsport are a good choice because of their experience in supplying the whole kit to EV users. (Such as me!)
Electric Motorsport can also supply the PERM motors, which are brushless, but I don't think they have as good a specification as the 1003 brushed DC.
Lynch have a good reputation for quality but their prices are much higher. When I bought my Mars 0709 the equivalent Lynch was more than double the price but I'm sure would be more durable since it can take up to 400 amps compared to the 0709's maximum of 300. Incidently I have my controller set to a maximum output of 210 amps to avoid overheating the motor. I measured the motor temperature with a probe and found that at 300 amps the temperature rose quickly.You see my 330Kg plus my own weight of 85Kg is about the maximum that the Mars 0709 can stand. The 1003 could give me much stronger acceleration and hill climbing but this would surely reduce my range and challenge my battery pack. 
If you look on the GWL website you will find the maximum advisory continuous discharge current for the Lithium batteries. This is 3 times the Ah rating , so a 100Ah cell can be discharged at 300A for upto 15 minutes. If you multiply this by your pack voltage (probably 72V) then you will find the maximum power that your controller can supply continuosly to the motor. You can, of course, exceed this figure for a short time, but it is advisable to have some means of controlling the current you draw so that you don't exceed what your batteries can safely give you. As I have mentiond, this can be done by programming your Alltrax controller.
I hope this has given you something to think about. It is best to do a lot of thinking before you spend any money. EVs are not simple things. The batteries in particular can be easily damaged if you are too ambitious with your range and performance goals. Range has been my biggest challenge, but I hope with your lower performance requirements, you will be able to acheive your goals with a 72V pack of Thundersky or similar. The motor and controller are in some ways less important. I can only tell you that I have been very satisfied with my Alltrax/Mars combination.

Andrew


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## MalcolmB (Jun 10, 2008)

For lithium cells, Agni motors and chargers: http://www.ev-power.eu/index.php?p=productsMore&iProduct=353&sName=lfp020ah-3.2v-20ah

I haven't had any dealings with this company myself so you'll need to do a little searching for customer feedback.

The Agni motor is lighter and more efficient than the Mars motor, but more expensive.

The Perm motor you linked to is a brushless, 3 phase motor, which would require an (even more) expensive controller (Sevcon).

Alltrax controllers are available in the UK from Lemco, who also sell their own version of the Lynch motor: http://www.lemcoltd.com/

Dimitri (a member on this forum) sells the Mini BMS, which is very good value and is advertised in the sidebar.


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## martin300 (Nov 1, 2010)

MalcolmB said:


> For lithium cells, Agni motors and chargers: http://www.ev-power.eu/index.php?p=productsMore&iProduct=353&sName=lfp020ah-3.2v-20ah
> 
> I haven't had any dealings with this company myself so you'll need to do a little searching for customer feedback.
> 
> The Agni motor is lighter and more efficient than the Mars motor, but more expensive.



why LIFEPO4 (http://www.ev-power.eu/index.php?p=productsMore&iProduct=353&sName=lfp020ah-3.2v-20ah) and not LIFEYPO4 (http://www.ev-power.eu/index.php?p=productsMore&iProduct=291&sName=lfp100aha-3.2v-100ah)??

what about BMS (is suggested which one..)? What kind of loader??

What do you think to the PERM PMS 120l or 150l (see datashet 2 post before)??


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## MalcolmB (Jun 10, 2008)

martin300 said:


> why LIFEPO4 (http://www.ev-power.eu/index.php?p=productsMore&iProduct=353&sName=lfp020ah-3.2v-20ah) and not LIFEYPO4 (http://www.ev-power.eu/index.php?p=productsMore&iProduct=291&sName=lfp100aha-3.2v-100ah)??


My mistake, I meant to give the general site link: http://www.ev-power.eu/

There are suitable chargers on that site. Which one is suitable depends on how many cells you use. As Duxuk has pointed out, there are many other good suppliers elsewhere and it's well worth spending some time and doing some research first, so that you understand what options are available to you.

I answered your question about the Perm motors last time.


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## martin300 (Nov 1, 2010)

one more of my silly questions...

What about recuperation/regenerative breaking with my Isetta with your component suggestions?

thanks


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## Duxuk (Jul 11, 2009)

Yes you can have regenerative braking with a permanent magnet motor. You wouldhave to choose a controller with this feature. Some say that you can get 25% of your energy back but another technique which costs nothing is to brake as little as possible! Brakiing turns the energy of motion (kinetic energy) which is derived from your batteries, into heat in the brakes. If you look at the road ahead you can pften shut the throttle early and use the brakes very little. Before you finish your EV you can practice the technique in you ordinary car, but you may annoy the drivers behind you! In an EV you get very little engine braking so sometimes you can travel for a long distance with the throttle closed. SO, yes, you could have regen. with a Lynch type motor, but it will be more expensive to begin with for the right controller. With your budget you need to think carefully about your spending. That is why I would reccomend the Mars motor and Alltrax controller.

Andrew.


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## martin300 (Nov 1, 2010)

Hi Andrew,

if I look to "Elektric Motorsports" homepage I cant find the Mars 1003. Is the "EMC-RT200" ment?
They offer the RT200 with Controller Alltrax 7234. Is it worth to go for the Alltrax 7245? What is the benefit for me (and my Isetta) at 72Volt 100Ah ThunderSky choosing the 7234 or the 7245?

thanks
br
Martin





Duxuk said:


> The Mars 1003 motor would be the best choice of their range. It is brushed, that it is has carbon brushes which contractg the commutator, and permanent rather than electro magnets. It can give 11.5Kw (>15 Bhp) continuously or up to 23 Kw for a short time. I don't know of a European distributor but as I mentioned before, it is not difficult to import from the US. Electric Motorsport are the only company that I have dealt with and they were very helpful. They can also supply Alltrax controllers, which would be a good choice, I think. You can certainly buy Alltrax in Europe. There is a supplier in England who's prices were very good. However, I think Electric Motorsport are a good choice because of their experience in supplying the whole kit to EV users. (Such as me!)
> 
> 
> I can only tell you that I have been very satisfied with my Alltrax/Mars combination.
> ...


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## Duxuk (Jul 11, 2009)

The EMC RT 200 and the Mars 1003 are the same motor. EMS have a habit of giving motors their own names. When I bought my Mars 0709 they called it an Etek RT. 
As for the Alltrax controller, since the motor can take 400 Amps for one minute you may wish to go for the 7245 which can therefore give you the full power that the motor can produce. However, the motor can only take 200 Amps continuously. If you used the 7234 you could still have 300 amps available, but much less chance of over heating the motor. 
I don't think many people would want to restrict their maximum performance by going for the 7234 but I must admit that I have set my maximum output to 180 then later, 210 amps to avoid overheating. John Fiorenza of Mars told me that the 1003 could take twice the ampage of the 0709 so I beleive it must be a much stronger and better motor which will suit your heavier vehicle far better. You must, however, remember that the more power you have available, the more you will use and the more energy you will take from your batteries.
If I were in your position I'm sure I would buy the 7245. I would program it to give half the maximum output ie. 200 amps. I would drive it to see how it performed then decide if I needed more power. 
I worked out that I could replace my FLA batteries with lithium from the company in prague for less than £1500. (24 60Ah cells). My FLA pack cost £600 direct from the manufacturer. They would cost £690 today so lithium is starting to look very tempting. I may need a divorce to buy them, though!!!!!!!!!!!!!!

Andrew


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## martin300 (Nov 1, 2010)

Hi,

AGAIN THANKS to Andrew and MalcomB fo your BIG help.




I really want to remove the transmission because of weight and to simplify my system.

But I got feedback from a motor supplier which makes me unsecure:

_You can get take the transmission out of the vehicle, but with gearbox you can work with better adjustion of the power to speed. You will need less starting power and it will be not cheaper - because the ratio with timing belt also costs (bearings, timing wheels, timing belt ...) and the vehicle will be not best running up-hill. Remember - electric motor have high torque from low RPM, but also has not high efficiency at low RPM. So You will start high current with lower efficiency - more energy goes into heat, not in work._

What do you think about this statement from the supplier?


Next question: how do I realize the reverse gear? Do I have to install a "switch" or ... ???


Just for for the sake of completeness: to realize recuperation; is it right it is a must to choose the Agni and a different controller (which one)?


thanks
Martin


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## Duxuk (Jul 11, 2009)

Reverse is achieved with a reversing contactor from a company like Allbright. They are not the cheapest contactors but have a very good reputation.
As for a gearbox, you must remember that it will always provide some friction or drag, so at times it will require more energy to run with a gearbox than without.
I would look into building your own swinging arm with chain drive to the rear wheel. The motor coulod be simply mounted on the swinging arm and the chain tension would remain constant as the suspension compressed.
I built my own swinging arm and it all works well.
As for regenerative braking you can have this with any permanent magnet DC motor, but you need the correct controller. I will have a look on the Alltrax website to see which one of their controllers would be best.

Andrew


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## Duxuk (Jul 11, 2009)

I've just looked at the Alltrax site for clarification and the news is not so good! They only offer regenerative braking for separately excited motors, not for permanent magnet (PM) motors. They do offer "plug braking" but this brakes the vehicle by creating heat in the motor and controller, not by recharging the batteries. Regenerative braking is therefore likely to cost you more money so you must decide if you are happy to spend the money to gain some extra range. If your driving will involve a lot of slowing down to a halt it may be worth the cost, but if you will mainly be driving along at a steady speed, espcially on level roads, the you may decide it is better to spend less money. 
Do you live in a hiily area? Will you do much stopping and starting?
Myself I try to anticipate ahead and brake as little as possible. It is amazing how little you can brake. On a Saturday mornig when there is little traffic, I can drive 40Km to work only touching the brakes gently about 3 times!

Andrew


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## martin300 (Nov 1, 2010)

Duxuk said:


> I've just looked at the Alltrax site for clarification and the news is not so good! They only offer regenerative braking for separately excited motors, not for permanent magnet (PM) motors. They do offer "plug braking" but this brakes the vehicle by creating heat in the motor and controller, not by recharging the batteries. Regenerative braking is therefore likely to cost you more money so you must decide if you are happy to spend the money to gain some extra range. If your driving will involve a lot of slowing down to a halt it may be worth the cost, but if you will mainly be driving along at a steady speed, espcially on level roads, the you may decide it is better to spend less money.
> Do you live in a hiily area? Will you do much stopping and starting?
> Myself I try to anticipate ahead and brake as little as possible. It is amazing how little you can brake. On a Saturday mornig when there is little traffic, I can drive 40Km to work only touching the brakes gently about 3 times!
> 
> Andrew


OK, I understand. Recuperation is to complex and to expensive for my project (there is a lot of money going into my project with spare parts, ..).

Yes, there are some little hills here (max. incline is 10%) and on the way to my job (15km) i have 10 traffic lights.
But I understood i have to change the way of driving with an EV.

br
Martin


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## martin300 (Nov 1, 2010)

After working on the restoration job 3 days and nights ..

My Isetta needs a lot of steel and extra spare parts I didn't expect before.

This means my overal conversion budget is about 4400 USD!
What to do now? Is there a chance to go on with my project??

thanks
Martin


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## Duxuk (Jul 11, 2009)

Hello Martin,
sorry I haven't had a chance tp send you any pictures of my swinging arm yet. I'll try to do it this week. If steel is needed don't worry, steel is not expensive. I bought a cheap MIG welder with which I have built all my trikes. If you have never welded then you can learn quite easily. A little instruction from someone who knows how to weld will help.
Which steel parts need repairing?
I know that many people start a project and then give up, but I would encourage you to carry on because what you make will be something amazing!
Do you intend to carry a pasenger? If not then you could make a battery box on the passengers side of the vehicle which would balance your own weight. You would want to seal the box but vent it to the outside, maybe through the floor. 

Andrew.


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## martin300 (Nov 1, 2010)

@Andrew: I am OK with welding (just tried to say it is a long way for me because a lot of rust..). Waiting for the swingarm pics (don't hurry ). 

what do you think of choosing following main components:

- Lynch LEMCO LEM-200-D127 72V
- Sigmadrive PM model PMT835M 72-80V 350A / 60s 120A Medium
- CALB with BMS and 72V 70Ah (45km should be possible?)

how much can I get out from calbs (80%)??

thanks
br
Martin


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## martin300 (Nov 1, 2010)

Do you think above configuration is OK for my Isetta??

THANKS

Martin


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## brainzel (Jun 15, 2009)

martin300 said:


> how much can I get out from calbs (80%)??


You *can* get 100%, if you are OK with 1000 cycles.
If you want to get 3000 cycles, you should only take 70% capacity out of the cells.
Usually you would get much more out of the cells, then the amperage printed on the cells. Probably 75Ah out of your 70th, reduced by time.


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