You could be in for a few problems getting the system back in service mate,it will defo need a new battery and possibly a new SAB in the sounder.
Start by replacing the control panel's backup battery and whilst your in there check all the fuses,
Isolate the mains power for the panel before you open it and have your code at hand to hopefully silence it when you connect new battery.
Try it and come back to us :)
Be safe.
e manno, March 2013