Veritas 8 alarm?

I have a veritas 8 alarm and the control box has started to buzz , can be quite annoying as its quite load , i no longer use the alarm as had new doors fitted, i want to stop the box from buzzing, when you take the cover off the alarm goes of , ok silenceing it, then 20 mins later will go off from battery back up. if you take the back up battery out the control box, will this silence the alarm for good, or does the bell box also have a backup battery ??