The present invention provides a power source for biomedical electrodes and other electronic devices comprising a galvanic cell in a state of partial construction. The galvanic cell generally comprises an anode conductor, a cathode conductor and electrolyte-containing substance. The anode is in electrical contact with a first quantity of electrically conductive medium and the cathode is in electrical contact with a second quantity of electrically conductive medium. The electrolyte-containing substance is separated from at least one of the anode or cathode until the cell is activated by allowing the electrolyte-containing substance to contact the anode and the cathode. Use of the galvanic cell in a drug delivery device is also disclosed.
