We have 2 APC Back-UPS 600 ups devices. The model number is listed as: BN600G. They seem to work OK. I don't know the age or condition of the batteries. The batteries were about 12.5V DC when they were installed in the UPS's. The batteries have been allowed to fully charge over night.
When the UPS's are powered On and plugged in to an AC outlet they show normal lights and produce 120V AC without anything being plugged into the UPS outlets. When I unplug the UPS's to test the operation on battery only, the voltage falls to about 93V AC and the UPS's periodically beep to indicate that they are unplugged.
If the battery condition is poor, I would expect that the UPS would show to Replace Battery and/or that the UPS would not run long when not plugged in. I would not expect that the output voltage would fall by almost 30V on battery. It...