Well, I removed the battery and found a web vendor that had a replacement for $18. It is a very common 12volt cell and was available from several vendors. The unit is back up and working well again.
I have experienced several black-outs in the past few years and this UPS can keep my CPU, 19" monitor, cable modem & network switch operable for enough time to save any work in progress and shut down my system.
In closing, it is a well designed unit with adequate power for most home or small office systems. But I was a little put off by the short life of the original battery and incorrect replacement information listed by APC.