PSA: Low Power mode on 2021 MBP limits USB charging to 500 mA maximum

[mastercheif91]

Discovered this while trying to charge my iPhone 13 Pro with my 2021 16" MacBook Pro using a USB-C -> Lightning cable.

The limit is applied for devices that are connected *after* the setting has been changed.

So if you want to see the limit in action you must first disconnect / reconnect the device after changing the Energy Mode.

 

[pshufd]

Does Low Power Mode extend battery life besides charging speeds on ports?

 

[mastercheif91]

Does Low Power Mode extend battery life besides charging speeds on ports?

Yes. It downclocks the CPU as well.

 

[UltimateSyn]

Does Low Power Mode extend battery life besides charging speeds on ports?

Yes. It downclocks the CPU as well.

I believe it also limits ProMotion's max refresh rate to 60Hz.

 

[pshufd]

Yes. It downclocks the CPU as well.

Do you have a link to a video or article? I'm curious what it does for battery life in terms of percentages or hours doing a common task.