Back-UPS CS 500 (BK500EI) battery replacement indicator flashing

[Anonymous user]

I have a problem with my rather old device (7-8 years probably). Battery has never been changed, it's still original one.

It blinks red "replace battery" LED with chirping sound 1x every 1 second. I tried turn-off-get-battery-out-hold-power-button-for-10-seconds procedure and it does nothing. Voltage on the connectors is 13.5V, BUT after I try to power it up, it shows some strange voltage (~5.8V). After removing the battery and following de-energizing procedure, it goes back to 13.5V.

As I can remember, battery terminals don't show any meaningful voltage, therefore I suspect it went belly up.

Anyhow, I would buy a new battery, but I'm not sure that UPS is healthy. Is there any way to figure it out?

The events that brought to this state is my stupidity and possibly a short circuit in my home grid. I was working on the main distribution board and completely forgot to turn off UPS. So, UPS supported my computer till battery died. Maybe it overdischarged and died due to the age. Later, feeder switch in my house went off due to a failure of some equipment. I thought maybe UPS fuse blew off.

Nevertheless, it provides voltage to battery terminals, but sth is not right.

I was planning to buy another APC UPS (CS 350) for my other PC and use that battery (as it is the same RBC2 model) in this faulty one to check if the battery is the issue. But, I'm concerned if the UPS itself is faulty, it could damage my new battery.

Any suggestions?

[BillP · Accepted solution]

well, a flashing replace battery LED indicates the UPS believes the battery is disconnected. this can be if it is physically disconnected, if the UPS has an internal issue detecting a good battery, or if the battery is "toast" and the UPS can't even see it.

if the battery is 7-8 years old like the unit, my bet would be on an issue with the battery even though the voltage may show good at some point with a voltmeter.

considering your alternative of a new unit, you can look into the Trade UPS program which may be smart - get a discount on a new unit which comes with a new battery and new UPS of course with a 3 year warranty (i think).

there is some more info here on that I think and other options: http://www.apc.com/site/recycle/index.cfm/apcs-recycling-and-take-back-programs/

Trade UPS might be better because on some of these smaller VA units, a new battery may cost just as much as a new unit.