I have the same problem and what's worse, after having the motherboard and the battery replaced by samsung only to see that the problem is from the faulty OS, they don't want to have the watch replaced as "the watch works ok, and the parts are new". I've filed a complaint with the authorities and i'm also thinking of fileing a law suite.
I used to get 6-7 days of battery life since October, only after the update on May 29, 2019 it barely reaches 4. Looks like contacts is using most of the battery, and the Samsung Health update from May 28 is also not transferring to watch properly, connection dies fast.
Not sure what it did exactly but choosing the Optimize option on the watch seemed to have fixed the battery drain for me. When you choose Optimize, it wants to turn off connections, lower the brightness, etc. I let it change the brightness (from 7 to 5) but I kept bluetooth and wifi enabled. And I changed the brightness back to 7 almost immediately after the optimization. I'm now back to 3 days without a charge. I took it off the charger Monday morning around 6:45am and I'm still wearing it now, Wednesday night around 7:15pm and I'm at 22%.
Monday morning through Tuesday evening around 7pm, it was down to 49%. It drained 4% overnight so I was at 44% when I put it on around 7:30am this morning.
This is the 42mm Galaxy Watch, btw. It's looking like it's now performing like it was before the One UI update. I had also done a factory reset after the One UI update and that did not fix the issue for me.
A factory reset seems to have done the trick for me. Not just a normal reset but a true, hard, factory reset and a complete Uninstall/Install of the Galaxy Wearable app on the phone. I did not restore any of my backups. Such a hassle but at least my watch is back to "normal". Well, I'm still having issues with updating the Samsung Health app... so there's that...
I even did the reset and then backup from the app and still my Samsung watch battery drains 4x as fast. I went from 100% to 36 % while sleeping 5 hours. My watch can't even make it through the day. I'm starting to think I need to switch watches to a solar/ thermal watch charge and drop Samsung all together!
Updated my galaxy watch to one ui yesterday . My battery performance on my s10 (SD855) dropped dramatically . Screen on time reduced to 4.5 hrs . Previously it was 5.45 hrs .
Annoying battery draining notification keeps popping First it started with Spotify, so I had to uninstall it. But the same notification kept popping up even when Spotify wasn't there to be found. Then the same notification started to annoy me every single day about the stopwatch
Samsung - take ownership of this issue. 300 dollar watches should not become useless after 2- 3 months of use.
In short - receieved watch as a Xmas gift. Pretty good features and about 4 -5 days battery life between charges. In the last week, the phone drains to dead in less that 5 hours. Previous readerboard entries say "solved" by turning off all features.
What happened to make the battery life suddenly suck? I don't know, I'm not a multinational corporation with almost endless resources. I'm a guy with a useless watch who just wants it to work without me having to invest hours of my personal time researching.
I'm purchased my Galaxy watch late last year. Worked fine with plenty of battery life. Now (May 2019), even though I have changed no settings, the battery now drains in about 14 hours. When charging, the watch says it has charged to 100%. What has happened? This needs to be addressed.
A side note, I did for the first time use PowerShare to recharge my watch with my new S10e phone. I don't do that regularly. Could that have something to do with it?