Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

BanjoDudeAhoy

macrumors 6502a
Original poster
Aug 3, 2020
862
1,536
Hello. Whenever I unplug my M1 MBA and go from wall power to battery, the display dims.
That's despite the "Slightly dim the display on battery" setting being deactivated.

Any ideas why this is happening/what I can do to restore the correct behavior?


1693477587947.jpeg
 

bogdanw

macrumors 603
Mar 10, 2009
5,746
2,768
Have you tried turning it on and off again? I'm referring to the "Slightly dim the display on battery" toggle. Enable it, close System Settings, disable it.
 

BanjoDudeAhoy

macrumors 6502a
Original poster
Aug 3, 2020
862
1,536
Have you tried turning it on and off again? I'm referring to the "Slightly dim the display on battery" toggle. Enable it, close System Settings, disable it.
I felt stupid for not having tried it but I did it now - still the same: I pull the plug and the display gets noticeably dimmer :(
 

bogdanw

macrumors 603
Mar 10, 2009
5,746
2,768
The setting is saved in /Library/Preferences/com.apple.PowerManagement.plist
To read the plist from Terminal
Code:
defaults read /Library/Preferences/com.apple.PowerManagement.plist
In Battery Power, ReduceBrightness = 0
If it's not, probably System Settings is not saving it correctly.
In any case, you could try to delete /Library/Preferences/com.apple.PowerManagement.plist and redo the settings from System Settings.
 

adrianlondon

macrumors 603
Nov 28, 2013
5,089
7,708
Switzerland
Check the "low power" settings. If it switches to low power at any point, that dims the display. it's annoying, as I'd otherwise enable the low power when on battery.

Screenshot 2023-09-01 at 13.18.43.png
 
  • Like
Reactions: bogdanw

BanjoDudeAhoy

macrumors 6502a
Original poster
Aug 3, 2020
862
1,536
The setting is saved in /Library/Preferences/com.apple.PowerManagement.plist
To read the plist from Terminal
Code:
defaults read /Library/Preferences/com.apple.PowerManagement.plist
In Battery Power, ReduceBrightness = 0
If it's not, probably System Settings is not saving it correctly.
In any case, you could try to delete /Library/Preferences/com.apple.PowerManagement.plist and redo the settings from System Settings.

That is 0, indeed.

But...

Check the "low power" settings. If it switches to low power at any point, that dims the display. it's annoying, as I'd otherwise enable the low power when on battery.

This is what it says for me.
Setting it to "Never" worked.

1693568060022.jpeg


Now I'm not sure if this should be considered a bug. I think I'll check it on Sonoma later and if it does the same thing I might report it.

Either way, thanks to both of you :D
 

BanjoDudeAhoy

macrumors 6502a
Original poster
Aug 3, 2020
862
1,536
I'm running Sonoma, and it does the same. I assumed it was deliberate.
It might be.
The reason I feel it might be a bug is that this the Low Power mode essentially cancels out another setting without that fact being mentioned. If using Low Power mode were to gray out the display dimming option with a note that you need to disable Low Power mode to be able to use display dimming on/off, that'd be a bit more transparent.

But I may be crossing over into UI/UX nitpicking mode here :D
 
  • Like
Reactions: adrianlondon
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.