Electric Car Motors, Generators, and Perpetual Motion

by Glenn Harris
(Dallas, Texas)

Perpetual Motion Machine Powers Electric Car...I wish!

Why can't a generator be added to the EV's system to keep the battery recharged...preferably one that draws from the energy that the battery is already creating?

Hi, Glenn!
Because there's still no such thing as perpetual motion, although people are still giving it a go. Can't blame them, really. So why do they fail?

Ahem.

Physics Lecture Alert: May cause dizziness, sweating, mild heart palpitations. You probably won't die, but ya never know.

Here we go...

The second law of thermodynamics is the one that usually gets in the way of perpetual motion: that's the law that says that in a closed system - your electric car, for instance - chaos will eventually WIN. The batteries will run down. The whole job of running your car is a downhill process, in terms of energy: you start with high potential energy, you burn up a lot of kinetic energy, you end up with low potential energy. Then you plug in to the wall socket and start all over again the next day.
This means no matter how good your generator is, you'll never get as much energy back from the system as you put in. All a generator can do is turn a given quantity of mechanical energy into electrical energy. It can't do magic.

Speaking of magic, Glenn, I'll bet you already know that the battery doesn't create energy, it only stores energy (which came from somewhere).

Regards,
Lynne