4

For example:

  • A USB-C monitor is connected to a laptop with a USB-C cable.
  • The monitor receives video/audio and power over the USB-C cable.
  • The laptop is plugged into a power source.
  • The laptop has a built-in battery.

When the laptop is unplugged from the power source and reverts to battery power, what happens to the monitor, does it power off or stay powered on?

EDIT

Of course something like this is up to the manufacturers discretion, but I mean how do typical USB-C monitors/laptops behave?

olfek
  • 289

2 Answers2

8

Yup, they do. Admittedly, your milage might vary, but most of these monitors run over 5v (not PD), and using 'alt' mode for video on USB C.

I've gone through 2 - they are generic aliexpress models with different resolutions, and they will run off a laptop on battery power as long as there's a signal, and they are not aware what the host device's power source is.

Journeyman Geek
  • 133,878
1

I have a Lenovo L15 USB-C display, and it works regardless if my laptop is powered by a charger or not.

Contrary Journeyman Geek's experience, it does appear to use USB PD. In fact, the display has two USB-C ports, and it can pass through power to the laptop.

marcelm
  • 752