This was originally posted on APC forums on 8/30/2013
Last week this unit began beeping and the RED "Replace Battery" LED was lit so I ordered a new replacement from APC. While installing the battery I noticed:
1- a slight arcing as the final battery connection was made
2- the fan began running immediately with no AC power.
The fan was obviously running on battery power and I assumed that was the power drain that caused the arcing when connecting the battery. I then plugged the unit into an AC outlet and after a few minutes I heard some relay chattering. It sounded like a small relay and not the clunk you hear when a backup switchover occurs. The chattering was intermittent and stopped after a few minutes or so. I assumed the new battery's charge may have been low initially and it had now charged sufficiently to exceed some threshold related to charging characteristics. I didn't see or hear any other problems so I let the unit continue charging while monitoring the battery voltage (measured about 25.3 to 25.4VDC). Sometime later I noticed the front panel GRN and YEL LEDs were both blinking about once per second or so. I checked the user manual and found no mention of this particular LED code. Also it appeared the battery voltage was dropping slowly and I waited for a while thinking this might be some kind of extended battery condition test but after several hours I decided this was probably not the case (battery voltage dropped to about 24.5VDC or so) and I disconnected the AC plug and the positive battery connector. I reconnected the battery, connected to AC and this time I heard no relay chatter but after a while I saw the same pattern on the LEDs. This pattern repeated itself several times but right now everything is reconnected and the fan is running but so far no LEDs are lit or blinking. I put everything back in the case so I can't read the battery voltage to see if it's charging or being discharged. I guess I'll know eventually if the battery runs down. Otherwise, after the recommended charging time, I'll test it with a load attached.
Does anyone know what this all means?
BTW, I replaced the battery about two years ago and for the first time went to a Batteries Plus for convenience. They claimed to be fully certified by APC for replacement batteries but I was surprised their battery only lasted 2 years (very light duty too, this UPS protects only network modem, router and a Magic Jack Plus). The battery had also leaked a bit which was very unusual. I have quite a few APC UPS's here and have always used APC batteries in the past. I usually get 4-5 years of service and have never had a leak before. So either I have learned a good lesson here or maybe the problem is actually this UPS. I hope that is not the case since I just spent about $100 to get this new battery from APC!