Abstract: A thin battery of the Le Clanche type incorporating a multiplicity of electrically conductive layers and sheet separators arranged to cooperate in conjunction with electrochemical material to form a multicell battery. Continuous frame-type sheet seals are thermally bonded to the periphery of each of the separator and conductive layers to provide an insulative sealing arrangement. The outer peripheries of these frames also are heat sealed to provide a rigid, secure border seal for the battery assembly. The sheet separators are positioned intermediate superpositioned ones of the electrically conductive layers.