Windows 10: Why does power slider recommends greater power in battery than when plugged in?

The Windows 10 power slider shows a recommended power setting that is higher when on battery than when plugged. The reason is not intuitive for me. Can someone explain?

:)

 

Battery Slider vs Power Options

The Battery slider power control is not completely independent, obviously some settings would be common.
Early versions of Windows 10 had more than one Power Plan, but they changed it into the one plan, Balanced (recommended) and then added a Power Mode slider control to the Battery icon.
Which makes it a lot easier than going to Power Plans.

i.e. The Power Mode slider control is the equivalent of a different Power Plan.

All part of a general shift from the old Control Panel to the Settings App.

 

Battery Slider vs Power Options

What bearing if any does the slider have on the power options (from control panel)
I slid it to better battery but the power plan was still set to balanced?

Are they completely independent?

I needed to leave my laptop on over night and the fan kept starting up (not sure why, it was only downloading some files). I set it to better battery assuming this would limit the cpu so it wouldn't get so hot, it didn't. Changed my power plan to power saver and changed max state to 60% and it was fine....

Slider seems to do nothing.

 

Power and battery

I just had a black screen; all I could see was the mouse arrow. I researched on my other laptop and discovered it's a common problem with Win10. I tried a few recommended things but nothing happened: black screen and mouse.

For some reason I got it into my head to remove the battery and leave the laptop just plugged into the wall. It started normally and some 6 programs I tried so far have worked perfectly. So now I am wondering whether I should have both battery and wall-power at the same time. Should I perhaps remove the battery permanently and just run the machine on power?

Thanks for all advice, opinions, gossip.

I just called a friend and he suggested I run the machine on battery only until the battery is down to, say, 20%, then plug it in again to power until the battery is back to 100%; then unplug it and run on battery only. Ad infinitum. Any opinions on this process? Thanks again.