Not sure about the not recognising the new battery properly but I can tell you that the BATTDATE 2009-09-26 has no effect on the ups function and is a field you change manual if req using the command line tool.
Did you hot swop the battery if so you sometimes will need to do a self test for it to register the new battery
Also look at the apctest section on this page https://help.ubuntu.com/community/apcupsdit tells you how to set battdate and recalibrate the battery etc.
In order to run apctest, you must first stop the ups stuff in unraid