I have an concept electric car, i calculated it will need 15,000 Wh stored in batterys to operate over its required range (100 miles) on a certain drive cycle. I am attempting to work out how many batteries i need The motor it is powering has a voltage rating of 156 vDC specs here: http://www.azuredynamics.com/products/force-drive/documents/AC24LS_DMOC445ProductSheet.pdf so does this mean that in Ah this is equivilent to 128 Ah? (P.t=IV.t = 2000 = I.156) if i were using say, 3.3v batteries would this mean i need 48 (48x3.3=158)? Also what are the effects of battery efficiency? If i have a 90% efficient battery does that mean my power is limited by 10% or is this just for the battery life?