Update 27/12/21:
Using watch for more than 2 months. Swicthed to classic bt model after 3 weeks of using 44mm bt model. Must say that battery little bit improves on latest update and after using watch for a few days when battery calibration thing has finished. With ligth usage it gives 2-2.5 days of battery life. imo, Its still far from good. The watch at least should offer a software based lite mode (instead of watch only mode) that users can get basic notifications, exercise step counting etc like a regular fitness band with about 7 days of battery life.
First Post on 10/21:
As noted by many users Galaxy watch 4 series have some battery life issues. I'm trying to figure out root cause (with limited tools, not much help from Wearapp's battery menu). I did some tests on GW4 44mm BT model. 2-4% per hour battery drain when watch is idle is too much for a smart watch really. Even when airplane and power saving modes enabled at the same time (no BT, no Wifi, no AOD, no SPO2, screen brigtness on 15%, only 10 mins heart rate on (runs once or twice an hour), sleep tracking and workout detection is on) while watch is idle in this state without any screen activity it drains battery around 1.2-1.5% per hour during day and around 1.5-2% over night during sleep. All this suggests something in the background drain battery fast. Battery menu on wear app doesnt give much clue since list of apps there (samsung health services, screen activity, ui etc.) all combined shows only about 1/3 of total battery drain. So what does drain battery the most, about remaining 2/3 of total battery drain, when watch is idle? Is it WearOS itself? Is there a tool application that shows more battery info than Samsung's Wear app, like Gsam battery on phones?
I think most likely root cause of battery drains are software based, Wearos and/or Samsung side, and they can be improved by devs. For instance; maybe some process/services (wifi, BT, notifications, gps, google services, health services etc. ) are running too frequently in the background which use cpu/memory power even if sensors/features are disabled and watch is inactive. There might be bugs and/or just bad implementations. No matter what, they should be found and solved by WearOS/Samsung devs. Maybe solution is as simple as changing the frequency of one service/process call that cause the most battery drain. Letting users change/tweak those settings that affect battery life would be better idea in fact.
Much cheaper watches or fitness bands last couple weeks even a month with like 2/3 battery capacity of GW4. They provide similar workout and health stuff, basic notifications, remote media control etc. With all features on they give much better battery life than GW4 with all smart features off (no notifications, no wifi, no BT, power saving on etc.) even much better than when Galaxy watch 4 is waiting idle doing nothing. Definitely WearOS is not battery optimised and buggy. Samsung apps might be making it worse as well.
