Battery calibration can be performed by software, network management card, or manually. On the newer units (SUA, SMT) software calibration has become more accurate so you can give it a try. On older SU models, it’s best to do the manual hardware calibration. If you’re not getting the run time you thought you should have with the software method, perform a manual calibration to get a more accurate run time calculation.
Some people only do software calibration and consider that good enough, others prefer to do a manual calibration as a tried and true way of getting exact run time numbers. Neither is really wrong, it’s a matter of preference.
Follow these steps to do a proper manual calibration on your APC UPS:
1. Battery must be at 100% capacity when the Runtime Calibration is initiated/started. (charge the UPS for 24hours prior)
2. The UPS must have 30-34% load on it during the calibration (Constant load, try: lamps, computers, monitors. Measure load % by PowerChute)
3. Disconnect the serial/USB comm cable from the UPS (you don’t want PowerChute to shut down equipment)
4. The battery must be discharged completely (unplug UPS from wall outlet, let the UPS to shut off completely due to a discharged battery).
5. Remove the attached load (ie – lights, computers)
6. Let the UPS charge for 8 hours while OFF (plug back into utility power, press OFF button when UPS turns ON)
7. Turn on UPS (run time should now be accurate)
If you’re confused about this process or stuck on one of the steps, email us at firstname.lastname@example.org or give us a call toll free at 866-311-1945.