On watchOS 7.3.1 and Dead Apple Watches →

Jay Peters:

Apple released watchOS 7.3.1 on Monday, and it could help fix an issue that prevents some Apple Watch Series 5 or SE smartwatches from charging while in the battery-saving Power Reserve Mode. But even the software update might not fix the issue, according to Apple. If it doesn’t, the company will repair your watch for free.

Apple Support:

To check if your Apple Watch is affected by this issue, place your watch on the charger that you normally use, then wait at least 30 minutes.

If your Apple Watch still won’t charge, contact Apple Support to set up a mail-in repair free of charge. Your watch will be examined before service to verify that it’s eligible for free repair.

This comes on the heels of a charging issue with some MacBook Pros. I’m sure they aren’t actually related issues, but what a weird set of problems.