Resetting The Samsung Galaxy S8's Battery
The instructions are attached to the end of this post as ResettingS8battery.pdf
They can be saved and viewed on your computer since the phone will be turned off most of the time.
It turns out that factory reset won't fix battery issues. It only resets settings and reinstalls software. The incorrect battery level comes from the memory chip inside the battery itself, and factory reset doesn't touch this.
Thankfully the battery memory can reset itself with these steps. Also one of those steps will need you to charge the battery for at least 6 hours without being turned on, so it's best to charge it overnight.
The short version is:
-
Flatten the phone until it can't turn on anymore.
-
Charge the phone overnight without turning it on.
-
Keep charging and restarting until the home screen says 100%.
.