Arlo System Update: Low Battery Detected

[retiredat44]

I have 3 Arlo Pro cameras, with batteries installed. A couple of months ago, I put the camera on power adapters, a/c to D/C with the lines and power plugs powering the cameras. Now I am getting a notice from one of the cameras: 

'Arlo System Update: Low Battery Detected'

how can it be low? it is plugged in. The camera is working, I checked it.

Temp is fine. it is Oregon, and out of the rain, in protected areas, Temp maybe 40 degrees. Not currently raining.

The other cameras, which are closer to the weather, less protection have no errors.

What to do?

The camera showing the low battery shows the red battery, Camera on the left of the 3 on the page which a copy snapshot is attached.

[TomMac]

check the connection of the ac power... pull and replug, test output at end of cable if able.

[jguerdat]

A reboot of the base may also help.