SUA750 Battery Issues

[rebuilder]

I recently noticed that the "replace battery red led" was on while in normal operation. I shut the unit down removed the two batteries and installed new ones. The problem is that the unit will not restart with the new batteries. It will go into test mode and run for a few minutes but will not restart. I have performed these tests without a load. I have rechecked the battery connections multiple times to insure that there were no issues with the wiring. New batteries are fully charged.

Suggestions on how to proceed would  be appreciated.

[Teken]

I would start by installing APC Power Chute Business Edition (PCBE) software if it hasn’t been done so already. Once installed and connected to computer system call out what the active faults / errors are present.

Provide a screen capture that is (viewable) on the APC Forum as to the following states: Input / output line voltage, frequency, battery voltage, connected power (watts).

The system will indicate the last transfer state from self test, failed self test, replace battery, internal fault, AVR active, etc.

Regardless of all the above you should measure the battery voltage and call out what it is. Verify (IF) there was a fuse in the older battery pack this fuse isn’t blown / broken and measure to insure it shows continuity! ☝️

If the battery voltage is fine and the fuse. Reinstall the battery into the system and let it charge for at least 24 hours while the unit is off but connected to AC Mains.

Once 24 hours has passed turn on the unit. The system should begin the Self Test and complete its POST. If the self test completes (great) than go into PCBE and tell the system a new battery is / has been installed.

Initiate another Self Test and confirm PCBE validates this process has been completed successfully. If so initiate a battery calibration with at least 30% connected loads attached to the UPS outputs.

If the above completes you win! 👍

If the unit continue to behave the same way after letting the new cells charge. You may consider completing a Brain Dead procedure:

Brain Dead: Remove any connected loads. Remove AC Mains from the wall. Disconnect the battery cartridge. Press and hold the power button until you hear a click / beep.

You may not hear anything at all . . . ☝️

Reconnect everything minus the connected loads. Reconnect the USB cable so PCBE can see how the unit behaves.

Power up the system and it should initiate a Self Test. If it passes connect the loads to the output.

All of the above should be seen and captured by PCBE Software. To complete the validation process unplug the UPS from AC Mains. The unit should beep indicating a loss of power and running on battery only. PCBE should reflect all of this and software should be able tell you the current battery voltage and estimated operational runtime.

Report back once you’ve completed these steps and the results. 👍

[rebuilder]

Responding to your list of items:

A - I installed PCBE and connected it to the UPS port on the SUA750. The quick status indicated nothing/blank screen and reported that the UPS was not connected. Hitting the test button produced readout from PCBE indicating that the SUA750 was in backup mode at 75% capacity hence it clearly was connected to the UPS line. There was no load on the SUA750 during this time.

B - Fuse was not blown on the battery harness and showed continuity. Voltage was 13.5 volts on each battery.

C - After charging the batteries for 24 hours. The SUA750 ran the self test fine. When I hit the power button it shut down. The was no output to PCBE running on the computer.

D - Ran the brain dead sequence you defined above. PCBE software indicated communication lost after the self test was terminated by pressing the power button.

[Teken]

As of this writing what does PCPE indicate the input / output voltage is? Does PCPE show the system is charging the battery? 

If you remove AC Mains from the wall does the unit beep and LED reflect the correct state of being in battery only? Does PCPE also reflect the same condition?

If yes - Reconnect the AC Mains and confirm the system reflects its charging the battery.

During this (static) test without a connected load the battery level should not drop very much and the operation runtime should be several hours. 

If the above is true continue to enter the new battery installation date via PCPE. Once that is done initiate a Self Test via PCPE.

If it passes initiate a battery calibration with at least 30% load attached to the outputs of the UPS. Once complete let the system recharge the battery and report back how the system behaves now. 👍

[rebuilder]

Thank you for your several replies to my question. Today's response is listed below:

AA - As I stated in "A" above PCPE reports that the UPS is not connected when plugged into the mains. PCPS does not report a model number at this point or anything else. When I press the "on" button there is a short click (sounds like a relay closing) with the SUA750 going to off when the button is released. The sound repeats when the button is pressed subsequent times. PCPE continues to report offline.

When I press the test button and wait for the beep, the SUA750 goes into battery mode and the UPS starts to operate reporting output voltage on the PCPE screen. PCPS correctly reports the model SUA750. Input voltage is reported as zero with output voltage reported at 121 volts ac 60 cps. All other items in the PCPE drop down menu work. This mode continues and the SUA750 never goes into “on” mode. The battery just discharges.

BB – Nothing happens when AC mains are removed, the SUA750 continues the backup mode. PCPE reports no change beyond battery backup.

CC – Operation run time when in battery backup mode is 70 min with no load on SUA750.