Abstract: A reserve cell is described for providing electrochemical energy and which is capable of long shelf life in the reserve state. This cell comprises a combined prismatic electrode chamber overlayed with a compartment containing the electrolyte. The electrolyte is prevented from access to the electrode chamber, by a frangible sealing means. The reserve cell is designed to be rapidly actuated by a separable actuator means of which the reserve cell actuator means described in U.S. Pat. No. 3,484,297 is preferred. The electrolyte compartment is completely lined with an electrolyte impermeable lining forming the electrolyte container which is collapsible. Upon actuation the applied pressure forcibly expels the electrolyte from the electrolyte container into the electrode chamber.