@sjm1027
The camera that Google Nest uses in its floodlight fixture is the Google Nest Battery Camera, which can run on battery power but can also be plugged in (ours has been plugged in since we got it in Sept. 2021) or connected to power (as in the floodlight fixture). If the camera is always connected to power, you should never get a low battery warning; we've never gotten one in over 3 years.
Is your floodlight camera by any chance on a switched circuit that is sometimes switched off?
If you go to your camera in the Google Home app and go to Settings | Battery, it should say "Plugged in" with an infinity symbol.
