t's often the case that after updating the latest version of watchOS, some Apple Watch users claim their battery life is terrific while others say it's terrible. That's not unusual. All of our devices are so complicated now that even small differences can result in significant disparities in power and performance. If you're having problems (or just dealing with a sluggish Watch), here are some troubleshooting tips you can try!.
Reboot
Press and hold down both the digital crown and the side button simultaneously.
Keep them held down until you see an Apple logo.
Let go.
Re-pair
Launch the Watch app from your Home screen.
Tap on your Apple Watch at the top of the screen.
Tap the information button (looks like an "i" with a circle around it)
Tap Unpair Apple Watch.
Tap Unpair (Your) Apple Watch to confirm.
You can also un-pair right on the Apple Watch:
Press the Digital Crown to switch to the app launcher.
Tap on the Settings app.
Tap on General
Tap on Reset at the bottom.
Tap on Erase all contents and settings.
Enter your Passcode to confirm.
Set up as new
Launch the Watch app from your Home screen.
Tap on your Apple Watch at the top of the screen.
Tap the information button (looks like an "i" with a circle around it)
Tap Unpair Apple Watch.
Tap Unpair (You) Apple Watch to confirm.
You can also un-pair right on the Apple Watch:
Press the Digital Crown to switch to the app launcher.
Tap on the Settings app.
Tap on General
Tap on Reset at the bottom.
Tap on Erase all contents and settings.
Enter your Passcode to confirm.
Once it's done, start the setup but don't restore from backup. Set it up as a new Watch.