A METHOD OF GENERATING ELECTRICAL ENERGY FROM A BATTERY IS DISCLOSED WHICH BATTERY HAS A CATHODE AND AN ANODE SPACED APART WITHIN A CASING AN ENCAPSULATED AQUEOUS ELECTROLYTE WITHIN THE CASING, AND A SMALL AMOUNT OF ADDITIONAL FREE ELECTROLYTE. UPON INTITIAL CELL DISCHARGE, THE EXPANSION OF THE ANODE RUPTURES THE ENCAPSULATED ELECTROLYTE FURNISHING A SUFFICIENT SUPPLY OF AQUEOUS ELECTROLYTE FOR THE REMAINDER OF THE CELL DISCHARGE. LOSS OF CAPACITY FROM SELF-DISCHARGE IS ELIMATED OR REDUCED TO A NORMINAL AMOUNT SINCE ONLY A SMALL AMOUNT OF ADDITIONAL FREE ELECTROLYTE IS PRESENT IN THE CELL UNTIL CELL DISCHARGE.