Scantronics 9651 panel beeping all night!?

My scantronics 9651 panel randomly starts beeping. The service light is on which I assume means a reset. The message reports 'batt missing, reset required'

If I type in my user code, the beeping stops, but it can sometimes start again. It's only started happening the night before but it will start beeping in the middle of the night and happen several times, which is getting more and more frustrating!

Is there a reset I can do myself or do I need to call an engineer out? If so, can any alarm company come out?