rover 416 sli alarm is playing up?

hi my battery went flat on my rover and since then my alarm has been playing up both key fobs are broken so the larm is done through the 4 digit eku code on in the door, the alarm will randomly go off for no reason ,when i used to lock the doors the indicators would flash 3 times to show the car was locked and alarm activated and when i unlocked it would flash once to show it was deactivated, now it flashes if and when it wants to when i lock the car and sometimes as i ulock the car the horn will beep once as if i have put the wrong eku code in the door please can someone help me on this or have any ideas what is wrong and what i need to do as i love my car and rely on her so much