Back-UPS RS 1000 beeping continuously

[Anonymous user]

Hello, this afternoon my Back-UPS RS 1000 started beeping non-stop.  It is not a continuous tone, it beeps about once per second and never stops.

- The green "On Line" LED is lit.

- The red "Replace Battery" LED is flashing.

According to the product manual, this combination of constant beeping and flashing lights indicates that the batteries are disconnected.  However, the battery is in fact installed and connected.  I tried unplugging and replugging the battery pack and nothing changed.

If I was convinced that the problem is that I need a new battery, I have no problem ordering one, but I want to confirm that a replacement battery would actually fix the problem.  It seems more like an internal battery wiring connection has failed.  In the past when I needed a new battery (on a different APC UPS) it beeped periodically for a few seconds at a time, not continuously like this.

Can anyone provide guidance on how to resolve this?

Thank you,

Dominic

[BillP]

Hi Dominic,

The UPS monitors the DC voltage present on it's internal DC Bus. If this voltage drops below the threshold for "detection" the UPS will think there is no battery installed even if it is. This can happen with older batteries as their ability to store DC power diminishes. I would advise disconnecting your load, turn the UPS off and leave it plugged in to utility overnight. If when you start the unit in the morning it fails to detect the battery, I would suggest a replacement of the battery or the complete unit depending upon the unit's age.

Secret Squirrel

[Anonymous user · Accepted solution]

Thank you very much for your reply Secret Squirrel!  I have turned off the UPS (and moved my loads over to a regular surge protector) for the night and I'll see what happens with it tomorrow.  Just for more information in case it is helpful, I did measure the battery voltage at the plug and it was 24.95 V. This was with the battery removed from the UPS so obviously there was no load on it.

Thanks again,

Dominic

[Anonymous user]

After leaving the UPS to charge all night while powered off, I turned it on this morning with no loads connected.  This time it ran through the self diagnostic and the battery failed, resulting in beeping for about 1 minute and the red "Replace Battery" light on solid, not flashing.  That result is consistent with needing a new battery, so I will go ahead and purchase new batteries.  I'm still not sure why it initially failed yesterday by beeping continuously as if the battery was disconnected, but I really appreciate your suggestion Secret Squirrel so that I can feel more comfortable that new batteries will solve the problem.

Thanks again!

Dominic