Yesterday Apple released the much anticipated ï£¿Watch. I still have yet to watch the Keynote presentation in depth (I'm going to do this tonight), but from what I recall (attempting) to watch it live it uses a magnetic induction charger. This is great, it's a pretty easy and stress free way to charge the device when it's battery is low.
As the ï£¿Watch won't be avalible until early 2015 independent tests for battery life can't be done. Personally if it can't get me through at least an 18 hour day then it'll be a hard sell. So why use a charger?
The Automatic (or Mechanical Automatic) watch uses a rotor which
spins from the movment of your wrist to wind the Main Spring which then powers the watch movement. This diagram shows either the rotor or the crown being used to wind the Main Spring:
Instead of winding a spring, the rotor could turn a turbine which would generate an electrical charge just like how a wind turbine works. This charge could then be stored in a battery or some sort of capacitor.
My theory only would work if such a smart watch used less energy than it could generate, but just like an Automatic- sometimes you have to wind the spring manually with the crown to get it going and then the rotor will keep it going for the rest of the day.
Think about it, a smart watch you never had to charge.
I bet Apple has already come up with this idea and to give consumers reason to buy the ï£¿Watch [S] they left it off the first generation.