Acorn, i go to lots of alarm calls where customers report a bleeping noise from their alarm panels. When in fact the noise is actually coming from the battery or mains operated smoke detectors. Acorn as an experienced engineer which i assume you are, you would know this. Mains smoke detectors which are fitted to all new build houses over the last 10 years have 9 volt pp3 batteries in them.
But i have since had a call from the customer and yes i was right.
As an enginner Acorn, the idea of this site is to offer quality factual advice to people and not to confuse them even more.
Regards
Nick 25 years experience as an alarm engineer
07842 480037
Nick, November 2009