I recently purchased a APC battery backup unit for a customer of mine. The price I paid for this battery backup did not match up with the features and design of this particular UPS, it was rather cheap compared to similar models. The APC Back-UPS XS1000 is a sleek 600 watt UPS with a bright blue LCD back lit display and quite a list of great features.
I did have one initial issue with the unit. About 48 hours after charging the unit and submitting it to a low 35w power draw (laptop) for a few hours, the unit began to beep twice every couple of seconds. No errors or events registered on the unit and all the measurements were not showing any signs of trouble, but the battery was depleting rapidly. APC UPS units normally will beep four times every 30 seconds or so when running on battery, or if they flat out fail, one long beep is what I have always heard.
I was pretty upset that with it being new and already having problems with it. After some quick searching the APC forums and Google, it seems that this is a common issue with this new UPS. The fix that worked for me is as follows:
1. Turn off the UPS using the power button.
2. Un-plug the UPS from the wall.
3. Remove the battery from the UPS.
4. Let the UPS sit with the battery removed for 5-10 minutes
5. Re-insert the battery.
6. Plug in the UPS.
7. Power the UPS on.
You should now see that the battery has been drained (weird I know) and that the UPS is charging back up. What I also did to test this fix was to connect a cable modem and wireless router to the unit drawing a constant 5w of power to wait to see if the 2 beeps returned. So far, the unit has been sitting for 5 days now, and the beeping has not returned. The unit must have a logic controller that is faulty when turned on initially and needs reset.
Over all I am very pleased with this unit, it seems to be a good UPS once this issue is fixed. Hopefully APC will find the problem and fix for the next product revision.