Abstract: An electric storage battery having a battery gas venting system including: an electrolyte-trapping chamber; an exhaust port for venting battery gases to the ambient; a porous flame arresting filter between the electrolyte-trapping chamber and the port; a combustion chamber adjacent the exhaust port for the controlled combustion of the battery gases; a buffer chamber intermediate the porous filter and the combustion chamber; a partition separating the combustion and buffer chambers; and a relatively small aperture communicating the combustion and buffer chambers one with the other. The aperture between the buffer and combustion chambers preferably has an effective cross-sectional area which is no more than about one-half the cross-sectional area of the exhaust port.