As I was running with my GPS watch today, I was thinking about how much I hate charging it. The darn thing needs to be charged every other time I use it. Then I started thinking about how I would much prefer to wind it, and could you charge a battery with a spring, or even better it could be kinetic. So I googled it and found it has already been done. https://www.kickstarter.com/project...nt-the-worlds-first-kinetic-self-charging-sma It doesn't look terrible either.