Yeah that would be nice, or use a kinetic rotor to charge, I've heard about watches like that before, but they were all without display - rather using watch hands to show events. There's also a smart watch with oled screen that recharges with thermoelectricity - that is, it charges out of your body heat. I think it's called the Power Watch Matrix or something like that.
It feels like there's still place for some innovation in the smartwatch area, rather than just iterating and polishing like Apple and Samsung are doing right now. Even if those techs couldn't charge the watch fully it should at least add a lot to the standby time...
