Apple update watchOS 9 can now track your battery information. It will start tracking your charging habits. This will help slow your battery aging life down. battery aging for Apple is something users notice and have concerns with. Apple has created this feature in the update to ensure that the battery won't age too fast for users. Instead of charging the watch to 100% right away, it will learn your habits and will determine the best way and time to complete the charge to 100%. This helps with the aging, otherwise the phone will sit on the charger at full charge until it's taken off which affects the life of the battery. Instead, the watch will charge to 80% right away like the feature on the iPhone, then slowly charge up to 100% over time.