NOVELTY - An electric accumulator comprises an explosion-proof device comprising a duct for venting the gas that is produced by cells of the accumulator and having a venting outlet, and an element for sealing the venting outlet having flexible portion(s) having area(s) forming, in conjunction with the venting duct, micro-slits that allow the gas to escape when its pressure exceeds a level and whose width prevents the entry into the battery of any flames.    USE - For electric trucks, electrical equipment, telephone exchanges, uninterruptible power supplies and automotive starter batteries.    ADVANTAGE - The accumulator has explosion-proof features but is not equipped with explosion-proof pellets. It is inexpensive to produce and costs less than accumulators fitted with explosion-proof pellets. It is easy to manufacture.    DETAILED DESCRIPTION - An electric accumulator, in particular of the lead acid type, comprises a container for the active elements that make up the accumulator arranged in cell(s), and a cover (10) that closes the container. The cover has plugs for sealing the access to each of the cells. The accumulator is equipped with at least one explosion-proof device for the controlled venting of the gases evolved within the accumulator during its operation. The explosion-proof device comprises a duct for venting the gas that is produced by the cells of the accumulator and having a venting outlet at one end of it; and an element for sealing the venting outlet having at least one flexible portion capable of sealing the venting duct until a certain pressure is reached. The flexible portion has area(s) forming, in conjunction with the venting duct, micro-slits that allow the gas to escape when its pressure exceeds a pre-determined level, and whose width prevents the entry into the battery of any flames that develop outside the battery.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-section of a cover.    Plug (8)    Sealing element (9)    Cover (10)    Venting duct (83)    Venting hole (84)    Cylindrical surface (85)