Bluetooth is watch initiated, and only turns on 4 times a day (or when the user explicitly requests it with a button press). The pedometer is probably a special

Bluetooth is watch initiated, and only turns on 4 times a day (or when the user explicitly requests it with a button press). The pedometer is probably a special chip. You should compare this with the F-91W that gets 7 years on the same battery, and hobbyist hardware mods that get years out of the same battery running ARM chips.