Been having a few issues with my alarm sounding out a buzzing noise at all times of the day and night!  

Just had a proper look at it today, and it would appear that the backup battery in the siren is has blown out and buzzing because its holding JUST enough charge to do it!  Anyone know where i can pick one up from?

Its a 6xN280BC

i.e. 6 Button cells of spec N280BC.  I have found a place with the single cells, but Im lazy these days and rather than screw around soldering wires on the damned thing Id prefer to just buy a ready-packed battery!

Sorted, cost for a ready made cell was knocking on the door of £40 when I finally found one.  Individual cells £2 each at CPC.  Not the exact same cells, but voltage and Ah the same.  Working fine, now