battery went flat last week due to me leaving the lights on

since then the alarms been playing up...
after it went flat the alarm wouldnt sound, even if you set it off...
yesterday it needed a jumpstart cause it didnt have enough juice in the battery...
and now the keyfob doesnt work!!!
its a clifford concept 50....
anyone? might try and change the battery in keyfob, but not sure if they need to be paired in any way?