I have a question coming from a mechanical background, not engineer but mechanic HVACR . And a person whom loves cars and tinkers with them. The Nissan Leaf and the Chevrolet Volt why engineers never came up with any other ideas instead of plugging in or a generator that runs on diesel. the tires move when the vehicle is moving and if you could put rare earth magnets in the rim or in the tire expensive i know why you couldn't use these magnets and a set of coils to charge a second set of batteries and use the primary batteries. of course you would need to plug in at some point for the initial charge or the use of air conditioning heating radio chargers etc. but as an alternative to less efficient means and higher polluting options. I wouldn't expect it to be a perpetual motion machine but improved travel distances would be nice.