Hello my S9+ started to heat so much. About 1-2 weeks ago I upgraded to android pie and after that its startes to heat. When I charge to phone its going up until 50°C and ita stops charging. Its not fast charging. Even now when Im charging and using its 45°C. What should I do? How can I fix this? Its scary that its heating so much. I tried safe mode to be sure about application problem but its still heating in Safe mode too.
If this was my phone @ErdemC I'd first back up and remove any relevant Sd card and then factory reset.
If that does not help then seek a diagnostic test via a Samsung Service Centre.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.
I had the same problem and now solved, thank God. After I updated the software to Android 10, my battery started heating and overheating sometimes while working on it or while I am not and when I recharge. I never had this problem before for more than a year, it happened after I updated the software. Anyway, I can't keep the solution for me, so here it is, enjoy:
1- Go to google play services in your phone settings and then to storage then to manage storage and there click on CLEAR ALL DATA
2- After you do that, restart your phone and enter the developer mode by holding the volume up button with the bixby button and the power button and you will see a list. You can go up and down with the volume key +/- ... Choose the Wipe Cache Partition and make sure not to click on restore factory, don't panic just read and click what's needed and then restart your phone.
This is what I did and it solved my problem since that time. Yay!