Thank you all!
I call the manufacturer. The unit is (was) second best sold in the US. It has surge protector and the batteries (2) can be replaced for ~$47 + S&H. They can be disconnected as well, and then I have to prey that I don't have something like Excel spreadsheet open when the power goes off. I don't believe that sudden power stoppage would damage anything because: sometimes I shut off my PC at home with power switch; nothing happens. At work IT people instruct me to restart PC, in case the previous user forgot to log off. When I asked, they told me that switching power off could damage old computers, modern machines are not harmed as a result. I plugged UPS into my $5.99 surge protector, for no reason.
UInrelated question (and probably inappropriate too: when I start Windows XP Pro, I am prompted for password. I don't have one, so I click OK, the box dissapears and W loads. Is there a way to get rid of this annoying unnecessary box?