Your back-up battery needs replacing for a start. That is located in the main box (white box approx 12"x12").
Fit a 7amp 12v Battery.
Power down the system by switching off the mains power and connect your new battery first, then apply the mains power.
rP on a 9800 control panel means - Remote keypad missing, if the cable has not been damage to the keypad, following the above and then closing the main box then entering your user code should clear the fault.
The factory default code for a 9800 is 07890 there is always a chance the engineer has not changed it. Entering this code will make the keypad start to beep then entering 99 clear may reset the system if the first steps don't work.
Pete alarm engineer, June 2009