The fuel cell (2) is of the kind comprising an anode (12) and a cathode (10) between which an electrolyte (18) is interposed. Solid bodies (20) storing a hydrogen mass, able to be decomposed by combustion, are associated to pyrotechnic means (24,26) to release the hydrogen and bring it into contact with the anode (12). Means (38) tap the ambient air to bring it into contact with the cathode (10). Firing of the pyrotechnic means (24,26) is placed under the control of addressing means (28) embedded in the appliance (2). The surplus water produced by the exchange between the hydrogen and the oxygen is resorbed by the temperature increase induced by combustion of the bodies (20). The solid bodies (20) are supported by an interchangeable card (22).