http://www.wired.com/2014/08/could-you-charge-a-smartwatch-by-shaking-it/ http://www.wired.com/2014/08/could-you-charge-a-smartwatch-b... This guy did some nap

http://www.wired.com/2014/08/could-you-charge-a-smartwatch-by-shaking-it/ http://www.wired.com/2014/08/could-you-charge-a-smartwatch-b... This guy did some napkin calculations which show this kind of energy generation can barely keep up with the energy needs of a smart watch, let alone any kind of phone.