# New to the forum. Building a EV-KART. Have lots of parts, and need ideas.



## Jayls5 (Apr 1, 2012)

I am building a fun electric vehicle with my buddies, with electrical and mechanical engineering background. We are just getting our feet wet in the EV world.

I bought a "freshly rebuilt" motor and rear end off of a 4 person golf kart, supposedly pulled off of a "Club Car". From the looks of it, it's a 36v 2.5HP older series wound motor geared down and attached to an open differential. Picture:










I picked up two freebie golf carts "EZ GO" brand. These will be parts only. We have no idea what works, since we just grabbed them the other night. I will be posting details/pics later. On initial inspection, at least one of them is a 72v system judging by the (dead) batteries. When attempting to charge the batteries, it appears shorted out and even fully automatic charger connections are getting hot to the touch... basically I will be using them for a core only. The other had the batteries removed, and the motor is caked over with dirt so I can't verify specifications yet.

I have a Spare Curtis 1266 (or similar looking 48v) motor controller.
I have a Victor 885 24v Motor Controller (for basic brushed DC). I used it to test our 36v "Club Car" motor here from the picture:
http://www.youtube.com/watch?v=MBpx52udXNY

Torque of the motor hopping it off the stands: http://vimeo.com/37192962

I am still learning about SEPEX and series wound motors, so other than the voltage differences, why might I not want to use the VICTOR 885?

We are still debating on quantity / type of batteries, but on initial inspection, Lead Acid appears to be the best bang for the buck. On paper, they do have the highest amp/hour per dollar, but in a high drain (go-kart) application, I have to take into account Peukert's law and lower my expectations significantly. Regular marine/golf kart batteries appear to have higher AH ratings than sealed lead acid, but I don't know if high speed corners are going to slosh around the acid too much and cause damage.

So basically, EVERYTHING is up in the air right now depending on what we can source for cheap. We are going to modify one of the golf karts frames and weld it into a monstrosity with a custom suspension. I have recently looked into the "Mars electric" / ETEK motor variety too, but would like to stick with what we have if possible.

Any advice on what I should do for starters, what problems you think I will be running into, etc would be appreciated.


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## winzeracer (Apr 3, 2012)

Jay,

I am also just starting an Ev-Kart Build, I am an EE student. Check my build site for my BOM. 
www.winzeracer.com
I am choosing to go with Lifpo4 batteries for weight reasons and more electrical gadgets to play with. As far as your questions reguarding specific controllers I unfortunatly do not have any experince yet. But I will try to keep up on your build and watch the progress.

Brock


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## Jayls5 (Apr 1, 2012)

winzeracer said:


> Jay,
> 
> I am also just starting an Ev-Kart Build, I am an EE student. Check my build site for my BOM.
> www.winzeracer.com
> ...


Are you going the A123 systems route? Let me know where you buy your batts from and what charger you plan to use. Those batteries have an annoying charging algorithm.


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## MN Driver (Sep 29, 2009)

What's annoying about needing a constant voltage power supply that has built in current limiting and a method to stop charging once the amp draw is low? There are actually people using Meanwell power supplies that they've modified slightly to do exactly what they want for smaller packs for their ebikes or whatever they are trying to charge up.


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## Jayls5 (Apr 1, 2012)

MN Driver said:


> What's annoying about needing a constant voltage power supply that has built in current limiting and a method to stop charging once the amp draw is low? There are actually people using Meanwell power supplies that they've modified slightly to do exactly what they want for smaller packs for their ebikes or whatever they are trying to charge up.


It is a more complex charging method than standards lead acid batteries, at least I remember. As far as I have seen, they also appear to be more expensive for out of the box chargers. I'm sure I could fab up a microcontroller to control it to exact standards for cheap, but the less I have to do, the better


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## winzeracer (Apr 3, 2012)

Jayls5 said:


> Are you going the A123 systems route? Let me know where you buy your batts from and what charger you plan to use. Those batteries have an annoying charging algorithm.


I have decided to go with CALB 40ah 26 in series. For a pack voltage of 83.2v, although I work in manufacturing and have a connection overseas and am exploring a prismatic cell that claims 20C burst which seems interesting. Still thinking on charger but I want to be able to do.a 2hr quick charge at the track so it will have to be beefy. Possibly an Elcon pfc 3000. Any updates on your progress?

Thanks,

Brock
Www.winzeracer.com
84v 400amp e-Kart


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