Erroneous Low Battery Light?

[Anonymous user]

I have BP500CLR APC unit for my personal computer and have had it for many years. The battery died (~4 years so not surprising I think the last one lasted about that long as well) and I ordered a new one. I installed the new battery, let it charge overnight before connecting everything and turning it on. However, once everything was connected I get frequent beeping and low battery light flashing (not overload). I tried a calibration and everything actually seems to work fine - I even threw the breaker and it operated as expected (for the expected amount of time) but it still flashes intermittently and after I installed some monitoring software I was able to see in the log that I have several coupled events 'battery disconnected' 'battery reconnected' (they are more frequent than the occurrence of the low battery light flashing). This same software allows me to turn off the beeping so I have that going for me but does anyone have any idea what going on? I checked the battery connections and while they don't seem to fit as snugly as the old batteries they are connected.

[Anonymous user]

I haven't tried with a voltmeter, however, I can get a status report anytime through a command line request in Terminal (Mac) - and the voltage varies but not abnormally - here's the latest status report:

Last login: Fri Mar 11 10:58:35 on console
[HOMEBASE-6:~] CROSS% apcaccess status
APC : 001,037,0941
DATE : 2011-03-11 11:00:05 -0700
HOSTNAME : HOMEBASE-6.local
VERSION : 3.14.8 (16 January 2010) darwin
UPSNAME : HOMEBASE
CABLE : USB Cable
MODEL : Back-UPS LS 500
UPSMODE : Stand Alone
STARTTIME: 2011-03-04 17:05:42 -0700
STATUS : ONLINE
LINEV : 119.0 Volts
LOADPCT : 16.0 Percent Load Capacity
BCHARGE : 100.0 Percent
TIMELEFT : 35.2 Minutes
MBATTCHG : 50 Percent
MINTIMEL : 5 Minutes
MAXTIME : 0 Seconds
SENSE : Medium
LOTRANS : 106.0 Volts
HITRANS : 133.0 Volts
ALARMDEL : Always
BATTV : 13.8 Volts
LASTXFER : Unacceptable line voltage changes
NUMXFERS : 0
TONBATT : 0 seconds
CUMONBATT: 0 seconds
XOFFBATT : N/A
SELFTEST : NO
STATFLAG : 0x07000008 Status Flag
MANDATE : 2005-09-14
SERIALNO : 3B0538X06285
BATTDATE : 2011-01-21
NOMINV : 120 Volts
NOMBATTV : 12.0 Volts
NOMPOWER : 315 Watts
FIRMWARE : 16.b4 .D USB FW:b4
APCMODEL : Back-UPS LS 500
END APC : 2011-03-11 11:00:10 -0700
[HOMEBASE-6:~] CROSS%

[Anonymous user · Accepted solution]

That's the frustrating thing - it appears to perform perfectly ... it just doesn't know it. I performed a calibration and also a test using 44% load (recommended 30-50%; using lamps so no critical load) and it ran for expected time, gave warning beep at expected time and shutdown fine. I might try and swap out the usb cable but I seriously doubt that's the issue (which I think must be internal to the ups) - I think it is not registering that the battery has been replaced for some reason (I entered the new battery date manually in the software - just for my info). Any other suggestions? I suppose I should add that it is running on a Mac (but that's always been the case).