Some Apple Watch Series 5 owners have been experiencing battery issues with their devices that cause random shutdowns even when the Apple Watch is reporting high battery levels.
An inconsistent reading of actual battery level appears to be at fault, as in most cases, the Apple Watch reports near 100 percent battery levels for most of the day before dropping down to close to 50 percent and then shutting off. Macrumors reader Todd describes the issue:
Prior to a recent update, my watch had been accurate in reporting its battery level. It's hard to say which recent update MAY have created the issue, or if it's a result of something different, but I'm currently running watchOS 6.2.8. For the past few weeks, my watch has been reporting at or near 100% battery levels for the duration of the day - 5-6 hours at least. It will then drop down to around 53% and then abruptly shut off. Once restarted, it reports a battery level of 53% but will then shut down again if not placed on a charger.
Other users have seen a problem where the Apple Watch shuts down at around 50 percent battery, charges up to 99 percent in a short period of time, and then has problems charging fully to 100 percent.
There are complaints about these battery life issues on the MacRumors forums and the Apple Support Communities, plus iMore wrote about the issue earlier this year. From the Apple Support Communities:
I am having the following problem with my Series 5 Apple Watch, purchased four months ago:
1. After a full charge, the battery charge indicator remains stuck at 100% for approximately 4-9 hours.
2. The battery charge indicator then begins to decrease.
3. When the battery charge indicator reaches approximately 15-33%, the watch powers down suddenly, with no low battery warning (which should be given at 10%).
In summary, the battery charge indicator is essentially never correct.
Apple Watch Series 5 owners have been complaining about battery life issues since the device was first released in September 2019, and while it doesn't appear to be a widespread issue, there are a good number of people who are experiencing problems.
Complaints have persisted across multiple watchOS updates, and there have been a reports about battery errors after the latest watchOS 6.2.6 and watchOS 6.2.8 updates. Some affected users have been able to solve the problem by getting a replacement watch from Apple, but other techniques, such as resetting the watch, re-pairing, deleting watch faces, and more have not worked.
Given the mixed reports about the battery problems and the length of time that people have been experiencing issues, it's not clear what's going on but it appears that Apple hasn't yet been able to fix the issue.