In this article, we'll explain how to check the battery of your Apple Watch on your iPhone or smartwatch running watchOS 3 or later and iOS 10 or later.
Apple Watches have an impressive battery life, lasting up to 18 hours on a single charge under optimal conditions. However, that number might not hold true if you’re overly active on your watch all day. To check your watch’s current battery life while it’s on your wrist, follow these steps:
Swipe up from the bottom of your Apple Watch face and enter your passcode if prompted.
Go to the WatchOS control panel and tap the percentage icon (for example, 90%).