Symptoms: When unit is turned on, it flashes green for ~15 seconds, then flashes red with alarm tone.
Background: Unit battery went bad and was replaced with a 3rd party battery "RBC154 Compatible Replacement Battery for APC BN650M1 by UPSBatteryCenter", purchased on Amazon. Symptoms occurred during power up.
Corrective Attempts: Replaced battery with a known-good APC battery from another BN650M1, but symptoms remained. Put the compatible battery in the second BN650M1, and it works fine.
1. What, exactly, does the flashing red light with tone mean? It's not covered in the user docs.
2. Is there anything I can do to correct this situation, or do I need to buy a new unit?