The Movement framework for developing watch faces tries to steer folks toward low power consumption by default; the watch spends most of its time in standby, an

The Movement framework for developing watch faces tries to steer folks toward low power consumption by default; the watch spends most of its time in standby, and a custom watch face only runs code once per loop (which is once a second by default, although you can request more frequent updates from 1 to 128 Hz). This means most watch faces can actually stay under 10 µA as long as they don't need to update too frequently; up to about 16 Hz, power consumption remains decent. Anecdotally, my daily driver is coming up on 550 days on the same CR2016 coin cell from February 2022, and I think it's on track to make it to 2024. A far cry from the original's 7+ year battery life, but still pretty good considering all it's capable of!