Tamper proof battery enclosure

An electronic device comprising:

• a plastic casing defining an interior and an exterior, the interior defining a cavity housing a printed circuit board, an electrical cell, and a metal retaining clip for retaining said electrical cell in electrical contact with the PCB, the casing comprising an integral cover which permits access to the interior of the casing;
• and
• a flexible electrically insulative substrate on which is carried an electrically conductive pathway, the pathway being in electrical contact with the PCB;
• wherein the integral cover is formed as part of the casing, and includes portions of relative weakness joining the cover to the remainder of the casing, such that said weak portions may be broken by the application of sufficient force, to allow at least a part of the cover to be separated from the remainder of the casing, thereby creating an aperture permitting access to the interior of the casing;
• wherein the substrate is located adjacent the cover such that breakage of the portions of relative weakness also serves to damage the substrate, such that the electrically conductive pathway is interrupted.