I have an APC Back UPS CS500 - it is just running one PC, so not overloaded. Just recently it started clicking onto battery when there was no sign of any kind of power flicker. First a click, then it ...

I have just been sent this Back UPS pro to replace a couple of faulty CS500 USB models. With the USB unit it was quite clear that the UPS was communicating with the OS and the OS recognized that there ...