There is no such phone. PLEASE REMOVE the S from the 20.
The S line and the NOTE line are different devices.
You have ONE of the below:
Battery life will level out once your Note20 Ultra (5G) learns your usage habits. Mine did, as I now get home with 40-50% remaining, and the first week (received it on 8/18) I would get home at 20% at best. I am inferring that you have the Note20 Ultra 5G based on the forum you are posting in BTW.
Eveyone, including myself is complaining about battery draining fast. I switched from Note 10+ to N20U. Have you tested the camera? I took several photos today (default settings) and they don't have the glow of my Note 10+.
Here is what I found to be the fix for now. I have watched anything and everything I could find on N20U battery drain/fixes/etc. I have turned off location access for most things, tried to put to sleep most apps that weren't in use, charged the phone last night and unplugged this morning around 4:45 when I woke up. Started using phone at 100% battery power around 5 am. Doing nothing more than browsing, the battery drained 11% in 30 minutes. SO I went into settings, changed my display to the highest resoloution and dropped the refresh rate from ADAPTIVE down to STANDARD 60hz, recharged the phone back to 100%, unplugged it and since then, I've lost 12% battery since 6am and it's almost 11am. So in 5 hours I've lost the same amount of battery at 60hz that I lost this morning at 120hz in 30 minutes.
Yes, that Adaptive refresh rate is a big battery drain. I suspect this is why they don't allow it with QHD+ resolution, yet. Yes, people say "give us an option", but here we are, we have an Adaptive option, and everyone wants to use it, and now many complain about bad battery life. If we had an option for full QHD+ with 120Hz we would all turn it on, and then spend our free time on the forums complaining about terrible battery life. All 3 hours of it until our phones die.
Another thing that drains the battery is 5G (useless for most of us), and while some can turn it off, many can't, including myself, but I'm not actually complaining, I'm getting decent battery life here, about the same as I did with Note10+.
My hope is this can be addressed with a firmware update. I, like many others have been on the fence about keeping such an expensive device past the return period. I don't remember the s20's doing this right from the factory.
Noticed the same issue with my note 20 ultra. Apparently, the adaptive display and 5G are energy hungry features of the phone. In the power mode option, I tried lowering the setting to "Medium power saving" and it did help improve the life of my battery a little. Will reduce further to "Maximum power saving" and see if does anything significant.