Quote:
Originally posted by Tech
not true. the energy in most electric cars come from the braking. rather than turn the kinetic energy into heat on your brakes, it stores it as battery energy which fuels the acceleration.
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Nope. Regenerative braking gives the car SOME energy back, but most of the car's energy still comes from the wall outlet.
Think about it in terms of physics. If you put energy into the car to make it go, some of that energy is lost due to heat, friction (which is really just another form of heat) etc. You then store kinetic energy by braking, but you can't capture what you've already lost, and you can't capture what is lost in braking due to heat - regen. braking doesn't change the way the brakes work at all. They still generate heat. Regenerative braking actually uses the rotation of the wheels as a generator to feed power into the batteries. So you're still losing energy to the friction process of braking.
Put another way, if the car started with 10 units of energy, drove for 1 mile, and then came to a stop, and had 10 units of energy still, you'd have a perpetual motion machine on your hands.