[Samsung Galaxy S10 Questions & Answers] XDA1697413:
I noticed my Samsung S10 T-Mobile Snapdragon would drain about 15-20% overnight while asleep (6-8 hours) since last week or so. The drain during the day is also significantly worse, but it's easier to compare the numbers when on idle. The first weeks that I had the phone, I was losing less than 5% overnight (6-8 hours). I am not sure if this was caused by the security updates, carrier updates, or a rogue application. I made no changes to the phone settings that I can recall. My phone was connected to WIFI overnight, with cellular, cellular data, and Bluetooth on. Prior to going to bed I would charge the phone to about 80% and unplug it.

I installed AccuBattery after reading some forums and it showed that my battery drain overnight was about 2-3% PER hour. AccuBattery also indicated that my phone was in deep sleep +85% of the time. The breakdown per application does not total the 15-20% so there's something else draining the battery. Eventually, I uninstalled AccuBattery to see if it was contributing to the drain, and it made no difference.

Below are most of the things that I have tried and tested overnight while I slept (6-8 hours), all of them have been UNSUCCESSFUL at solving the battery drain. I might have forgotten some other settings that I have changed. Keep in mind that this took me over a week of playing around with these settings, and checking the battery right before and after I went to sleep.

Restarted phone (There's always someone who would suggest this if not written down)

Cleared Google Services, Google, and other Apps Cache and Data

Cleared Cache Memory (Through recovery menu - Tried this about 5 times at this point)

Reset the big 3 (Reset settings, Reset network settings, Reset accessibility settings)

Enabled Airplane Mode (Cellular, WiFi, Bluetooth Off)

Disabled Location

Disabled Sync

Disabled Always on Display

Disabled ALL Motions and Gestures (e.g. Lift to Wake, Double tap to wake, Smart Stay, etc.)

Disabled Video enhancer

Disabled Game Launcher

Disabled Bixby Routines

Disabled Nearby Device Scanning

Disabled WiFi Scanning and Bluetooth Scanning (Improve Accuracy)

Disabled Show icon when screen is off (under fingerprints - from Samsung Forums)

Disabled certain Apps (AR Emoji, ARCore, Briefing, Chrome, Game Launcher, Google, Facebook, Secure Folder, etc.)

Forced Stop certain Apps (Bixby, Secure WiFi, etc. - they seem to all come back after a couple of minutes anyway)

Enabled/Disabled Adaptive Power Saving (Tried both settings, made no difference)

Enabled/Disabled Auto Optimization (Tried both settings, made no difference)

Switched between Power Modes (Optimized to Medium, made no difference)

Change lock screen and home screen to a 100% black wallpaper

Ran Safe Mode overnight with ALL of the settings above (Airplane with Location and Sync Off, etc.) Still got a 15% drain overnight.

Last night after I got fed up with playing with the countless of options, I decided to Factory Reset the phone thinking that this would solve my battery drain problem. Well, WRONG. Still got a 15% battery drain overnight with only the core apps installed, in airplane mode, location and sync disabled, and other settings disabled. I did NOT restore any backups from Samsung or Google, nor installed any additional apps that did not come with the phone.

I have complained to Samsung through their Samsung Members application under Feedback. If you guys are on the same boat, I suggest we all start complaining so that they can start taking a look at this and hopefully release a fix.

If you guys have any tips or anything has worked for you guys, please let me know.