Quote:
Originally Posted by auto2
...or use virbration to charge the batterys. i saw a flashlight you had to shake to build up a charge. the shocks could do that.
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Enter Bose (yes, the same Bose that does audio):
http://auto.howstuffworks.com/car-suspension9.htm
The flashlight you shake is basically a piston-like motor. Instead of the rotor turning, it goes up and down. Either way, it induces a voltage in a coil, just not nearly as well as a rotary motor.