I purchased a Galaxy Watch 3 from Costco just a bit over 2 months ago and have enjoyed it thus far. Have wanted a smart watch for years, but they just weren't what I wanted in their early phase.
Unfortunately, the last several days, my watch won't hold a charge for longer than 8-10 hours before it is completely dead. Previously, I could get about 52-56 hours out of it with ease. I changed absolutely nothing on the watch in weeks, and actually changed to a more simple and dark watch face several weeks ago with no issue. I did not have many modifications away from the factory settings, as factory settings were pretty good.
Day #1 of a charge cycle was great, but a some point on Day #2, I noticed the battery was draining rapidly. Suddenly in 3-4 hours my watch was dead... I charged it up, then dead in about 8 hours again.
I've tried a different charger, tried various charging cycles (full dead to full charge, partially charge to full charge, partial charge to higher partial charge), reset the watch to factory settings, disconnected from phone... still cannot break the 8-10 hour mark anymore. My phone is not sending anything in a stuck cycle, so definitely not that. I had this happen once about a month ago, after being fully charged before bed and I woke up to a dead watch... but that went away with the next charge cycle.
** For Reference... I did everything that I could on this guide: https://www.samsung.com/us/support/troubleshooting/TSG01003232/
So update.... I threw my watch on the charger when it was at 30% and it sat there for about 12 hours. So far today, I'm only down 6% after 4.5 hours and even restoring my data and settings back to it first thing.... so sounds like it's back to normal.
Why this is happening is beyond me...
Okay.... after 26.5 hours, I'm only down 35% on this charge. What the heck is going on? This is probably the best runtime that I've gotten out of the watch. Why is this suddenly working now?
Well, it worked pretty decent for me for a while - hopefully it is/was working for you. Unfortunately, last night it went from about 51% to dead while I was sleeping. I always turn on sleep mode, so it's not like it was chewing the battery from the screen randomly turning on or notifications. I've got it charging again, and if it drains like this again, off to Samsung I go. I'm kind of surprised they aren't responding to this thread.