During the development stage of the Power Alarm, we decided that we would not compromise on the distance range. However, available wireless technology small enough to fit inside the tiny pebble would not work at distances over 25 metres. Attaining ranges of 40 to 50 metres would require innovative circuitry and a powerful battery.
To deliver the power necessary for such an extended range, the pebble uses a large cell battery CR3032. These are readily available from numerous internet retailers, but less common off the shelf. We are pleased to offer packs of 5 batteries which equates to approximately 1 month of use at 7 to 8 hours per day for £15.00.

Battery CR3032 (pack of 5) £15.00

CR3032 £3.00