VENT PLUG STORAGE BATTERY

PURPOSE:To prevent overflow of electrolyte from a vent plug by dividing the vent plug into an upper chamber and a lower chamber with a partition, installing a small hole in the partition, and installing a spray arrestor having Y-shaped cross section, hanging from the lower side of the partition in the lower chamber. CONSTITUTION:A vent plug 10 is divided with a partition 3, and an upper chamber C is closed with an upper cover 8 having small holes 9 to form a space. The partition 3 has a recess on its upper surface and a small hole 4 in its lower part. An electrolyte entered the upper side of the partition 3 through the small hole 4 is returned into a container when pressure inside the container is reduced. A spray arrestor 5 having Y-shaped cross section, hanging from the lower side of the partition 3 has gas permeability. The electrolyte entered from a lower cover 6 is despersed independent of direction against horizontal and vertical vibration of a vehicle, or converted into microparticles by striking the spray arrestor and sticked on the spray arrestor 5, then dropped on the electrolyte in the container. Overflow of electrolyte from the vent plug is prevented.