I had very good battery performance on my S10 (I got it in February) until the latest update got pushed through. Then suddenly the phone started running very hot and the battery life went to hell. I mean, really bad - it doesn't even last 3 hours, even when I'm not using it. This effectively renders the phone unusable. Any suggestions appreciated
First thing to try is clear the system cache files by turning the phone Off and then from a set series of button presses clear the system cache @ballaa
If that didn't help then put the phone in Safe Mode which disables downloaded apps but leaves the stock ones working and then see what happens. If the issue stops then one or more of your apps are causing this. Make sure they are updated.
Start deleting one at a time until it stops as a process of elimination.
As a very last resort back up and remove any relevant Sd card and factory reset.
A Samsung Experience Store or Samsung Service Centre can run a diagnostic test.