This unit is a few years old, and I'm certain that it's time for a new battery.  Up until a couple of weeks ago, it would beep and I was guessing that it was telling me something... maybe the battery was going?  But all the plugs were active and live.  Now, the backed up plugs are all dead but the other three are live.  I tried getting some advice from Conext, but they never answered my question about whether a new battery would resolve the problem.  They told me that it was out of warranty and perhaps I should replace the whole unit.  I checked the inside fuse and it's not burned out, but I don't know what else I can check to determine whether it's a throwaway, it can be repaired (by who in New England?), or if its just a battery issue?

Computers & Internet - APC - Conext 900VA (cnb900) UPS System