How does an automatic watch hold a power reserve?

Question

And how does mere movement power it? Cheers

In: 3

Answer 1

It has a weight pendulum inside that spins when the wearer moves. That spinning pendulum wither winds a mechanical mechanism, or activates a charger similar to the ones on the hand cranked radios and flashlights to charge the watch’s battery. On the ones with them, the battery is large enough that it only needs a tiny charge daily, as long as the watch is worn often and regularly