Product: Battery: Charging
Automatic watch battery   (+7)  [vote for, against]
Retrofit to make your cheap quartz watch automatic

A lot of quartz watches use little button batteries to power them. A lot of fancy watches use a rotor to harvest the energy of flailing human limbs.

This device has the form factor of a standard watch battery button cell. Most of the interior is used to house an eccentric rotor, which charges the remaining stub of battery.
-- pocmloc, Jan 26 2018

funny, and with a piezoelectric ratchet and pawl
-- beanangel, Jan 26 2018

In principle OK, but a radiothermal or Beta-capture cell would be way cooler* .

*In a metaphorical sense. Obviously, radiothermal batteries get quite warm in normal operation.
-- 8th of 7, Jan 26 2018

This could actually work. The available power would be (very roughly) dependent on the square of the diameter of the rotor - so maybe 1/20th that available from a conventional full-diameter rotor, but that's plenty for a quartz.
-- MaxwellBuchanan, Jan 26 2018

random, halfbakery