Reserve battery operated power supplies

A power supply comprising:

• a reserve power source for providing power, the reserve power source comprising:
• a liquid reserve battery which requires activation to produce power;
• an activator having a liquid electrolyte for activating the liquid reserve battery upon a mechanical activation of the activator such that the liquid electrolyte is forced from the activator into the liquid reserve battery through a communication between the activator and the liquid reserve battery;
• a pair of terminals operatively connected to the liquid reserve battery for outputting the produced power;
• and
• a mechanical stop for preventing the activator from activating the liquid reserve battery, the stop being selectively removable when activation is desired;
• wherein the mechanical stop comprises a member positioned between a surface of the activator and a surface of the liquid reserve battery for preventing the activator from activating the liquid reserve battery and the member comprises a safety pin having two prongs, the two prongs being positioned between the surface of the activator and the surface of the liquid reserve battery.