I received the One UI 8 on my Watch 4 Classic about 3 weeks ago. Shortly afterward I started noticing odd behavior. In particular, the watch would constantly reboot and eventually shut down. I finally figured out that the battery level was being depleted rapidly and the reboots were attempts to restart even though the battery level was not sufficient to allow that to happen. Since then, I have determined that the battery is draining after about 7 or 8 hrs of use...a problem I never had with the previous firmware! I have cleared cache, reset and rebooted innumerable times and this has done nothing to help the huge power drain this update is causing. Some posts say the system is learning my usage habits and could take up to 2 wks to resolve. I personally don't believe this and have never had such problems with any firmware updates for any computer, phone, etc. Additionally, as I try to change some settings, the watch crashes or restarts because the power drain is so great that it runs out of power before I can complete the changes. I have removed all unused apps and shut off all non-essential services, including wifi, etc which would normally use battery life during periods when such services are not necessary. There has been no improvement in battery life. Also, the Samsung Wearable App on my Android Phone now regularly crashes when trying to make setting changes and adding emergency contacts which is the main reason I got the phone originally. Unless Samsung puts out a fix for this, they have basically destroyed my watch which was working perfectly before the One UI 8. If they fail to either revert this watch to the previous firmware versions, allow such reversions or correct the problems with One UI 8, I expect multiple lawsuits to follow!
UPDATE: March 28, 2026--I just chatted with Samsung Support after making all the suggested power saving hints, and waiting for my battery to "learn my usage habits". The watch still only lasts about 6 hrs before going into a non-stop reboot loop which can't be stopped until finally the battery is completely depleted. TO MY SURPRISE, THE AGENT SAID THIS IS NOT A KNOWN ISSUE! I asked if a firmware update was going to be released and when...he had no answer! How Samsung is not aware of this issue when the web is replete with multiple complaints on this exact issue is mind-boggling! I'm left with trying to downgrade the watch to an earlier firmware version...I hope it doesn't "brick" the watch completely!
LAST AND FINAL UPDATE (4/4/2026): I was unable to find the exact firmware for my SM-R885U (42mm) so as a last attempt, I decided to try replacing the battery. Although I apparently slightly damaged the screen somehow (the watch still works and is basically usable), the battery replacement went well (the old one was slightly swollen!). As it turns out, after all my ranting, the entire cause of the battery drain was apparently NOT due to the firmware update, but due to a failing battery. My apologies to all who followed my attempts to correct what turned out NOT to be the firmware! My battery time is now back to about 1.5 days, as expected. I guess a 4 yr old battery should be expected to fail over time.
