Apple likes to talk about battery life in hours rather than capacity, measured in milliamperes. As a result, the latest Watch Series 8 has a claimed life of 18 hours, just like its predecessor ...

For the Series 4-6, case sizes were 40mm and 44mm ... t work with the 42mm Series 10 or 41mm Series 8. Still with us? Of course, the Apple Watch Ultra and Ultra 2 each feature a 49mm case.