SUA 2200 new batteries charged to 100% but test drops to 0%

[spart007]

I have 2x SUA2200RM (2011) ups's that are now doing the same thing. They have not been used for a couple of years after the batteries failed, so I decided to get them going. A new set of batteries arrived and I installed and charged for 24hrs. All looks good with a small 9% load, plenty of runtime but on doing a test it beeps and the batteries charge drops to 0% and takes a couple of hours to get back to 100%. I am stuck in this loop, is there something I am not doing right?

Thanks

[Teken]

A few things come to mind in no specific order of importance and relevance.

- Batteries: Cells should be the same amp hour rating or better so verify they are. Ensure the cells are fresh and not old stock by confirming the manufactured date on each cell. Depending upon the size and number of cells in a cartridge 24 hours may not be enough to fully charge the unit.

- Self Test: Complete a self test and let the batteries recharge and stabilize.

- Battery Calibration: Once the catridge is 100% charged complete a battery calibration by placing at least 30% load on the UPS and removing AC power from the wall outlet. Let the UPS run down the battery and turn off. Afterwards let the UPS recharge the battery cartridge and see what the results are.

If UPS is operating better and the battery charge indicator is more reflective of what you expect - Win! Keeping in mind if your UPS has the ability to tell the UPS a new battery cartridge is installed - Do so! As this tells the UPS to use a charging lookup table for best performance and operations.

If on the other hand by running a *Battery Calibration* with 30% load and 100% charged cells causes the UPS to shut down. This points to a bad cartridge that may have one or more bad cells inside. This is easily seen by measuring each cell on their own with a DMM and also load testing each cell to see how they behave.

It only takes one cell in a battery pack to cause the others to go bad to.