PURPOSE: To enable the detection of the over-charge state for the bent type alkaline battery while to lengthen the service life of battery for the enclosed type, by mixing the alkali metal and the carbon fiber for producing the compound with the active substance.

CONSTITUTION: The alkali metal and the carbon fiber for producing the compound are mixed with the active substance to provide the variation on the potential behavior at the final charging stage or at the open circuit of the alkaline battery. For the bent type alkaline battery H2 gas is produced from the negative pole at the final charging stage, but in this battery the alkali metal in the electrolyte and the carbon will produce the compound thereby when measuring the final charging stage voltage to decide the potential variation, the overcharge state of battery can be known. In the enclosed alkaline battery the hydrogen gas is produced at the final stage of service life to deteriorate the capacity abruptly, but when employing this battery the production of H2 gas is suppressed to lengthen the service life of battery.