Sparky - subscribed to diynot.com to thank you. You & Europlex just saved me ~£200 by posting how to change a faulty battery on a Scantronic 9651 alarm. Like the chap 3 years ago: £19.50 @ Screwfix for an identical battery, a little bravery when pulling the panel off in 'Installer Mode', and all of a sudden my wife thinks I'm a genius. Not for me to correct her, right? Cheers