Disconnect MBP 14 mag power cable and the external monitor shuts off

[transphasic]

I have been using my new MBP in clamshell mode plugged into AC power with an external monitor. When I disconnect the mag power cable the external monitor goes black as if there is no longer a video output being sent to it.

Is the MBP designed to stop sending video out to an external monitor if it is on only battery power? Or is this an issue with this particular external monitor?

 

[mystery hill]

Is the MBP designed to stop sending video out to an external monitor if it is on only battery power?

Yes.

“To use your Mac with the display closed, you need to connect your power adapter or connect an external display that also charges your Mac, such as the Apple Studio Display or 23.7-inch LG UltraFine 4K Display.”

Connect a display to your Mac - Apple Support

Mac computers support one or more external displays, depending on the Mac model. Here's how to connect an external display.

support.apple.com

 

[transphasic]

Yes.

“To use your Mac with the display closed, you need to connect your power adapter or connect an external display that also charges your Mac, such as the Apple Studio Display or 23.7-inch LG UltraFine 4K Display.”

Connect a display to your Mac - Apple Support

Mac computers support one or more external displays, depending on the Mac model. Here's how to connect an external display.

support.apple.com

Thanks, found it on google as well. Will search more thoroughly next time