It's not clear. It's possible that even if you don't use the fitness at all, you...

SECProto on May 9, 2023 | parent | context | favorite | on: Casio adds fitness features to original G-Shock di...

It's not clear. It's possible that even if you don't use the fitness at all, you'd still have to plug in once a month. Or maybe your situation would work, i.e. it could regenerate an hour worth over the span of a week.