2 battery backups die same day, within minutes of each other??

[Anonymous user]

I just woke up to beeping from my APC battery backup which was strange because the power wasn't out. I even plugged something else in to the same outlet to confirm it was working and it was. Still the battery backup died minutes later like the power had been out. I assumed the battery had just died, so I started shopping for a replacement. Minutes later, I heard beeping from another APC backup device and then it died! It would work when things were plugged in to the surge protector ports, but not the battery backup ports. 

Granted these were 2-4 years old, but what are the chances both would die at the same time?!? Also, shortly after both died, the power to the house did flicker, so is it possible something was going on in the night that caused damage to these? That's the only thing I can ponder that makes any sense.