BR1500G with new battery reporting low time

[Anonymous user]

I have a BR1500G and just replaced the battery with a new APC 124 battery pack.  I installed the battery and left it plugged in for 24 hours with no load.  But it reports much lower times than what it should.  With a 100W load it should last around 73 minutes.  But it reports about 53 minutes.  With a 700W load it should be 6 minutes but it reported 3 minutes.  

I read about a calibration routing but it was for SMART-UPS devices. It involved plugging in a 30% load or greater and make sure it never varies over 5% while you unplug the UPS and completely drain the battery.  I tried this with a 75% load but it was varying more than 5%. But it didn't seem to make any difference.  Any ideas?

[BillP]

Hi Steven,

You may also wish to try changing the battery replacement date in the PCPE software and attempting the runtime calibration again with a load closer to the 30-40% range.

Secret Squirrel

[Anonymous user · Accepted solution]

I tired that as well and it did seem to help.  The calibration was done with 31% range and it was a combination of fans and the few incandescent lights I still have.  I really don't anything else to plug in that would provide a consistent load.  

After all of this I got a load that was exactly 100 watts.  The battery time estimate on the front panel was 61 minutes.  I unplugged the UPS from the wall and it lasted 61 minutes.  The documentation from APC says it should last 73 minutes for a 100 watt load.  So that isn't too far off.   However when the unit is unplugged from the wall the output AC voltage drops from 121 to 113VAC and therefore the output wattage drops to watts.  You can see the lights dim and the fans slow a bit.  From the APC graph it should power a 90W load for over 80 minutes.  So I am only getting about 75% of the "advertised" time.   Is this just overly optimistic performance data from APC or is something wrong with my batter/unit?