It's always the way. Just when you have to make that important phone call, your smartphone tells you it's time to recharge your battery and then promptly dies. Little wonder then that the backup charger market has become such a crowded space. Arguably the most appealing battery blocks available are those that can also offer off-grid emergency power from sources like PV panels or kinetic energy. The Voltmaker takes the latter approach, providing your smartphone with enough juice to make a quick phone call with a flick (or more accurately, several flicks) of the wrist.
Read the full article: It's all in the wrist: The Voltmaker kinetic smartphone charger