battery backup ES 550 beeping twice, green light blinking red

[Anonymous user]

About a week after a power outage my battery backup ES 550 started beeping twice every 2 seconds and the green light started blinking red. Everything plugged to it works fine.

[BillP · Accepted solution]

I am having same exact issue.  Power down and back stops it for awhile (hours), but comes back. 

[Anonymous user]

Well, unfortunately, mine died when i turned it on after being unplugged for about a week. I never did get a reply from the tec department. I hope you have better luck.

[Anonymous user]

The battery in your ES 550 may have become weak with age. Over time they do wear out, 3-5 years is typical, but you may get less if the UPS is heavily loaded or the power quality in your area is low.

However, my recollection of these units suggests that these would sound a constant alarm and flash the red LED constantly if the battery failed a self test.

Although APC markets these 550VA Back-UPS ES models as being intended for computer use, they're really rather small for that task. It could be experiencing a momentary overload.

(I do not represent APC or Schneider Electric in any way.)