Question : Problem: Low Battery warning on Desktop computer

For the past week I have been getting Low Battery warnings on my desktop machine. Machine is plugged in to an APC Back-UPS ES 750. There are no error lights on the APC and the machine is otherwise working fine. Do I have a bad power supply? How can I find out?

Answer : Problem: Low Battery warning on Desktop computer

Probably not, it's an unusual message for sure in a Desktop system. I would narrow it down a bit. Plug the computer directly in the wall and see if you still get the message if not it could be a problem with the APC