Just to check before I start listing things, have you tried any troubleshooting already?
Since about two weeks ago I am also having an S8+ battery problem. Phone feels HOT even when on standby mode.
100%-->50% in 2 hrs
I have unistalled antivirus. See how that goes.
Trouble shooting shows now untoward issues.
Be sure to send us a screenshot of your Battery Usage chart after you've tested things without the extra antivirus downloaded.
I just wanted to reach back out and see if you were able to get this fixed up! If not, please let the Community know so that they can look into different ideas to help further.
Same here. I accepted an update in early May and tonight it went from 100% to 5% in 5 hours with very little usage. This is after I had a new battery installed this afternoon, so the new battery has not helped at all. I just turned disabled Lookout as I already have McAfee for a virus protector and I also have uninstalled about 8 apps and put all background running apps to sleep. I'll charge it back up tonight and report back tomorrow to give an update.