My figures are probably high since it dawned on me when you said that, that I was including the charging inefficiencies. I don’t have my PakTrakr yet which I can then use to do a true battery energy use calculation. The 240wh/mi estimate is my true cost at the meter value.

Coal_burner:

You’re right. A set of these batteries to run a car 40 miles would have a per battery draw much less. I wasn’t thinking of that part. The Tesla Roadster has a very small per cell draw because of its 6800+ cells. Just what you are saying.

kevin fitzgerald:

Anything which takes energy because of the motion of the car will rob the car of momentum and hence the motor will work harder to compensate. The generator will not be even 100% efficient so it will cause a net loss. For example, if you have ever ridden a bicycle with a generator light you know it takes energy to turn the generator: it is harder to pedal. After a ride feel the generator and it will be warmer than the air temp. This is part of the lost energy in the generator. One way to recapture energy is in braking. The electric motor can be turned into a generator to slow the car down and put energy into the batteries.