A:AnswerYour Apple Watch will track your sleep whether you’re sleeping during the daytime because you’re on night shift or you’re sleeping at night because you’re up during the day....it just tracks your sleep when you are specifically sleeping....zzzzz
A:AnswerUnfortunately no, the Apple Watch is much like the iPhone in that it is closed off. I believe even if you needed a battery replacement from Apple they would end up just replacing the old device.