Major FPS drops for games after unplugging charger

[allah gamingسمكة الله]

I know this isn't too Steam related, but this fps drop only happens on like source engine games, so please at least read through a little.

A lot of people have had this problem and I've seen posts for this on other support forums, but when I unplug my computer and my FPS drops from 120-150 to 20-30, plugging it in doesn't fix the the problem.

The fps drops just stays there unless I somehow update my Windows or Lenovo (which I can't do all the time). I have tried changing my power saving plan, but that doesn't do anything. I have no idea if my computer is broken or if this is fixable. Please help me!