Question : Problem: APC UPS1500 RM diagnostic problems

I just recently repalced the abtteries in two APC Smart UPS 1550 RM units.

One unit has a red light lit up under the icon of a battery with an x on it, it also has the green battery bar completely full.
The other unit has the green battery bar completley lit up but it is flashing.

Answer : Problem: APC UPS1500 RM diagnostic problems

UPS-Selftest

This is a procedure, the UPS runs at every boot. You can also press the Self-Test Button on den UPS itself.