The Apple Watch Ultra 2 takes the crown by doubling its battery life to up to 36 hours with regular use, and up to twice as ...

Battery life ... to 36 hours (on Series 10) and up to 72 hours on Apple Watch Ultra. It’s able to work on any Apple smartwatch running watchOS 9 or later meaning Series 4 and newer.

Even more essential to the sleep issue is the question of battery, which continues ... Using the Ring 4 along with the Apple Watch Series 10 over this last week and change, it’s apparent that ...