60 day old Apple Ultra battery dies after less than 12 hours
Recently My battery dies in less than 12 hours. Watch is about 60 days old
Windows, Windows 6
If the battery drains too fast after an update, see all the replies to:
has anyone had battery issues with the 10… - Apple Community
Battery Drain since watchos 7.4 - Apple Community
WatchOS 7.5 battery drain - Apple Community
FWIW, in some cases, unpairing the watch, completely erasing it, then pairing and restoring the backup will resolve the battery draining issue after an update. (Simply unpairing and pairing again may not work.)
Unpair and erase your Apple Watch - Apple Support
Also, some people have found that simply waiting a few days after an update resolves the battery draining problem.
Also see:
Apple Watch battery drain - the ultimate … - Apple Community
For repair & service:
Apple Watch Service & Repair - Apple Support