# BMW Isetta ideas welcomed.



## ldkl (Jun 24, 2009)

Hi guys I was wanting to get started with my first electric car. I want to restore an old BMW, and I think the Isetta would be a perfect electric car.
(Yes I know they are pricey)

What motor and batteries make the most sense for this light small car?

I was thinking possibly 48-72v of Lifepo4? (possibly 14 of the 200ah thundersky?) Would you look into larger brushless wheel hub motors to drive the thing (multiple scooter motors) or some other motor? Small warp?

I would just like some ideas for this particular car, range would need to be about 40-60 miles, top speed of around 50-60 mph. Could you go transmissionless? Some sort of bike or scooter type gears? Any sort of belt driven tranny type clutch system?

Sorry for the noob questions with this, I just feel there are many ways to build this car, and I want to hear what peoples ideas are for fun, cheaper yet functional, conversion ideas.

I saw the orange one online with the 4 e-bike brushless motors...maybe you could use 2 of the larger 1500w or 2000w brushless hubs?


----------



## rillip3 (Jun 19, 2009)

From what I'm seeing, it would probably be a fabulous EV, IF you can find someplace to stick all the batteries. Lithium will help with this, esp. since there's probably not a whole lot of weight to work with either.

I think 72v is overkill; the curb weight is listed at only 700 lbs!! What a dream. The curb weight of a golf car is around 900 lbs! A VW Bug curb weight is 1970 lbs! A VW bug with a 72v pack and what looks to be about a 6.7" ADC 6HP motor got 50 miles with 56 mph. Using Lithium will increase the range and the lowered weight should more than make up anything needed for the speed and range. You might be able to do a 48 volt with something like a 5.5" ADC 3.8 HP. I think with that weight, you could get up to speed. I'd be concerned about the range at 48v though, and because 72v is a more standard voltage for an EV, I would tend to go with that, just because others have done it as well.

Good luck, keep us updated, this looks fun!


----------



## Nomad (May 8, 2009)

The 200ah TS are HEAVY!!! You need to keep this in mind. Coming in at 8kg a piece your looking to add 850lbs just in bats.
Also your talking about running @ 150+ volts.
http://www.evalbum.com/2153 is an example of a 200ah with about the same curbweight as you.

In a 72volt system you would need about 23 batteries coming in around 400lbs.

For a 100ah 72 volt system your looking at 161lbs and that is much more managable. I doubt you could find room for 200ah TS batteris as they are BIG and HEAVY! 

Now how far will a 100ah 72volt system take you? I'd look into the evalbams for heavy bikes or light cars, you have about the same curbweight.

You might see 50 miles out of a 72v 100ah, but I'm not sure.


----------



## madderscience (Jun 28, 2008)

I'm willing to bet that 100AH at 72V using Thunder Sky lithium coupled with an alltrax 72V controller and a perm 132 pancake motor will make a great setup. The perm 132 could drive the rear wheel (isettas are a reverse trike if I recall) via a motorcycle chain. You would need to calculate your gear ratio for 4000 motor RPM at the maximum speed you expect to drive it (50mph or so?) as that is redline on that motor. In your case I am guessing that will end up being 6:1 or so.

Range with that setup ought to be at least 40 miles at speeds under 50mph. If you need more range, I think the next size up TS battery is 160AH.

Isettas are rare. The only one I've ever seen had rust holes the size of my head in it so if yours is in good shape it is worth preserving. try to make your conversion reversible (don't cut, weld or modify the chassis, basically, and keep the parts you remove) in case you decide to sell it later to fund a larger, or different EV conversion.

Good Luck.


----------



## ldkl (Jun 24, 2009)

You guys are right about the battery weight, I will have to stick with the 100ah ones...and that will probably limit the range...is there another motor that should be considered as well? Any brushless worth looking at? I wouldn't destroy the Isetta and also feel it should be able to go back to stock...but the engine is currently in need of a rebuild, and I thought this might be a somewhat less expensive EV project to get started with due to the weight and lower voltage required.


----------



## toddshotrods (Feb 10, 2009)

madderscience said:


> ...The perm 132 could drive the rear wheel (isettas are a reverse trike if I recall) via a motorcycle chain...


I don't know if they're all the same, but this is what I found when doing some research on them a while back. If nothing else, this pic should help with the discussion.


----------



## todayican (Jul 31, 2008)

found a few more pics.


----------



## ldkl (Jun 24, 2009)

That photo is correct for pretty much all of the US models. There are different ones. Some are reverse trikes, but those are more common in Europe as they were treated like motorcycles (tax,title, etc) if they had 3 wheels over 4.
Pretty much all of the US ones are just like that.


----------



## Penman (Nov 25, 2010)

I built an electric Isetta ten years ago. What do you want to know?


----------



## Wollysf (Sep 27, 2013)

Any updates on this - I have been thinking of the same project. Thanks.


----------



## commander (Mar 10, 2013)

Penman said:


> I built an electric Isetta ten years ago. What do you want to know?


 what kind of batteries did you use?


----------



## AlHensling (Apr 28, 2017)

I just completed a Isetta conversion that has a Top Speed of 42 MPH and a Range of approx 35 miles utlilizing Leaf Batteries


----------



## psron (Jun 19, 2012)

Old thread, but first things first... whenever considering a LIGHTWEIGHT project, think about a lightweight source for parts... 



...what other electric "vehicle" has to be very light?


Motorcycles.


Look for a scrapped (insurance) production electric motorcycle... IDEAL for this project, small yet powerful, very compact battery pack... just transplant and go... all charging is already taken care of, etc.


Bad example execution-wise... but...
https://www.youtube.com/watch?v=v68j01KiLG8


----------

