Battery drain when phone is not used.what. Can i do?

Here's what I tried when that was happening to my Nexus 6P:

  1. Charge it up and then perform a factory reset. Do not reinstall updates yet. See if the issue still happens. If so, may be a motherboard or battery issue. If not:
  2. Reinstall updates, do not install any apps yet. Again, see if the issue still happens. If not:
  3. Reinstall your apps one at a time. Some apps drain a ton of battery in the background. When I uninstalled Snapchat, Facebook and Instagram my battery performance was noticeably better.

I replaced the battery in my 6P but the issue (when battery hit 50% left it immediately showed 0% and shut off) still happened so now it's for my work music while plugged in.

/r/SamsungS8 Thread Link - i.redd.it