This was originally posted on APC forums on 10/20/2007
serge wrote:
I beleive I'm having an issue with my SU5000TXFMR.
I'm only getting about 13min of Battery Life which by all calculations seems to be a fraction of what I should be getting.
My load power shows 26.5% Watts and the LED's on the unit for load show 2 lights. Looking at the runtime chart full load for my unit is 3375 watts so I figure I'm sitting at about 993 watts. Theirfor on the runtime chart I should be getting 51min.
The batteries were replaced today since the old ones have been in use since 2001. I figured my short runtime was due to the very old batteries. So I hot swapped in the new batteries Friday morning and let charge for about 8 hours and ran a runtime calibration. I got about 13min the same as the old batteries and it said they were discharged. I noticed that the Battery Voltage was about 46 volts when the UPS went back to mains and said the battery was discharged.
I let charge again for another 8 hours thinking maybe the unit needed to do a recharge cycle. I ran another calibration test and again around 13min it said the battery's were discharged. This time I noticed that the Battery Voltage was just over 49 volts when it went back to mains.
My question is what can I do to get the proper life out of my new batteries. Replacing the batteries on this unit is very expensive and I'm very concerned that I'm not getting the runtime that I should be getting. Since I hot swapped the batteries is there something I need to do to tell the UPS the batteries have changed? I figured a calibration would do that.
Thanks,
Serge.
Soft calibration don't always work in my experience. Sometimes, you need to do a full discharge to calibrate it correctly. To do this:
-Charge 24 hours
-Disconnect loads
-Turn off power outage alarm in PowerChute to avoid nuisance. (optional)
-Plug in a 1.5kW or 1kW 120v space heater with manual settings and set on continuous.
-Turn off power to 208v input to the UPS.
-(check point)
Let UPS run the space heater on battery power until the output shuts off on its own. Ignoring all warnings. Time the actual duration the heater runs on battery. An operation duration of approximately ~27 minutes at 1.5kW or 50 min @ 1.0kW confirms the batteries are performing to specs.
If it fails this check point, there is a problem with your new batteries, or the UPS (not likely).
If it passes,
-Unplug the space heater
-Reconnect loads
-Restore power
The UPS should be calibrated correctly now.
