This was originally posted on APC forums on 1/12/2012
I have several RS 800s in the department. The last month one started beeping. So I replaced the batteries for nothing better to do. No change. Nothing plugged into it. When turned on the "On line" light blinks for a while then the "On battery" light coms on. It beeps then it clicks to On-line for a second before returning to On battery. It keeps cycling like this until it is turned off. There is nothing wrong with the power.
To day I have the same problem with another one. I tried dead heading and adjusting the sensitivity and now it goes to over load (with nothing plugged in.)
From what I am reading here this seems like a common problem whith these. I don't think it's worth sending back, between shipping costs and paper work and packing and all. I'm just going to get some new ones of another brand.