How to diagnose and improve poor battery life on Apple Watch Series 10 with watchOS 26.1?

Hi,

I am experiencing a significant battery issue with my Apple Watch and would like help getting it diagnosed.

Device and software

• Model: Apple Watch Series 10

• watchOS: 26.1

• iPhone: iOS 26.1

• Age: approximately 25 months

• Battery Health: 93%

• The watch does not have cellular

• I do not use workouts or GPS on the watch

Symptom

The watch cannot last through the night, even with very light usage. Typically, I charge it to 100% around 22:00. According to my sleep tracking, the watch is active for about 5.5 hours, and then it is completely drained.

During the day, battery life has also become significantly worse than before, even though I only use the watch for normal notifications, checking the time, etc. It works for about 5-7 hours.

The battery has worked fine for more than 2 years, and this issue has only appeared within the last ~2 weeks, in connection with the most recent update.

Troubleshooting already done

• Turned off Background App Refresh

• Turned off fluid glass

• Unpaired the watch from the iPhone and paired it again (several times)

• Reset the watch and set it up both as a completely new watch (without backup) and from backup

• Restarted both iPhone and Apple Watch multiple times

• Adjusted settings to reduce usage (screen and other options)

Despite all this, the battery life remains very poor, which does not seem reasonable given a Battery Health of 93% and such light usage.

[Re-Titled by Moderator]

Original Title: Apple Watch Series