Question about battery selection for EV build

[The Atomic Ass]

Originally Posted by Electric Frenzy

GREAT LINK!! So it seems that a series/parallel is the best configuration as it increases both voltage AND amperage. Those are very disappointing figures you posted for my battery choice vs the Zaps...

The WarP9 motor I plan on using is rated for no more than 156v (or so). I plan on running 144v but all of the performance charts only show power usage at 72v. Can I just double (or halve) those numbers to get ratings at 144v?

My understanding of DC motors is that higher voltages allow higher speeds, but higher amperage allows more torque.

I'll admit I don't understand how that works, but Paul Holmes demonstrated it in his controller build thread.

[Ryland]

the small 3.2 amp hour batteries would be great for an electric bicycle, or if you got about 300 of them they would work for an electric car... if all of your connections were perfect, if they are not perfect then your charging and discharging will not be even and you will wear some batteries out faster then others causing them to fail high amp hour batteries are the best way to go, then string them together for hgher voltage, the higher the voltage the smaller the wire can be in the motor so the more power you can get out of it, thus higher speeds, my 48v 1,400 pound car needs battery cables that are at least 0 gauge, my new cabes are 00 gauge, over 1/2" of copper conductor, with low voltage like that you start needing such large wire and switches that it limits you, of course low voltage is nice because I can grab the battery cables and feel it but not be killed, anything much over 48volts can badly burn, hurt or kill you.

[ConnClark]

Just use a bunch of cell phone batteries. US Cellular will exchange your run down batteries for free eliminating the need to keep them charged.

http://ecomodder.com/forum/showthrea...-car-8989.html