Abstract: A lead acid storage battery according to the present invention comprises a battery container for housing a plurality of cells, a middle lid for covering the battery container, and an upper lid for covering the middle lid, wherein, on the upper surface of the middle lid, a gas discharging port for discharging the gas generated inside of the cell and an electrolyte recirculating port for recirculating the moisture to be discharged along with the gas within the cell are formed as corresponding to each cell. A plurality of exhaust chambers separated by an exhaust chamber partition are formed in a space surrounded by the middle lid and the upper lid, and a mechanism for collectively exhausting the gas discharged from the gas discharging port to the outside of the battery by interconnecting the plurality of exhaust chambers is comprised.

Abstract: An object of the invention is to provide a lead acid battery having a liquid surface sensor (3) installed to a liquid surface sensor installation portion (2a) on a top face of a container lid (2), an electronic circuit board (4) contained in a recessed portion (2b) on the top face of the container lid (2), terminal connecting conductors (5a, 6a) connecting the electronic circuit board (4) to terminals (5, 6), and a liquid surface sensor connecting conductor (8) connecting the liquid surface sensor (3) to the electronic circuit board (4), preventing from catching on an object on the top face of the container lid (2) by insert molding the terminal connecting conductors (5a, 6a) and the liquid surface sensor connecting conductor (8) in the container lid (2), preventing the terminal connecting conductors (5a, 6a) and the liquid surface sensor connecting conductor (8) from being corroded by an electrolyte solution even if the electrolyte solution is spotted on the top face, and improving the outer appearance.

Abstract: A lead acid storage battery according to the present invention comprises a battery container for housing a plurality of cells, a middle lid for covering the battery container, and an upper lid for covering the middle lid, wherein, on the upper surface of the middle lid, a gas discharging port for discharging the gas generated inside of the cell and an electrolyte recirculating port for recirculating the moisture to be discharged along with the gas within the cell are formed as corresponding to each cell. A plurality of exhaust chambers separated by an exhaust chamber partition are formed in a space surrounded by the middle lid and the upper lid, and a mechanism for collectively exhausting the gas discharged from the gas discharging port to the outside of the battery by interconnecting the plurality of exhaust chambers is comprised.

Abstract: In order to provide a battery charging state arithmetic operation device which can judge a charging state of a battery currently being used easily and in a short time, there are provided battery voltage calculation means 6 with specified load for calculating a first and a second battery voltages when a battery current is at a specified load current value from a first I-V characteristic of the battery which is in a first state as a currently used state and is stored in first I-V characteristic storage means 3 and a second I-V characteristic which is in a second state where the amount of remaining energy is small and is stored in second I-V characteristic storage means 4, and SOC arithmetic operation means 7 for calculating an SOC (charging state) of the battery in the first state by using the first and the second battery voltages calculated.

Abstract: In order to provide a battery charging state arithmetic operation device which can judge a charging state of a battery currently being used easily and in a short time, there are provided battery voltage calculation means 6 with specified load for calculating a first and a second battery voltages when a battery current is at a specified load current value from a first I-V characteristic of the battery which is in a first state as a currently used state and is stored in first I-V characteristic storage means 3 and a second I-V characteristic which is in a second state where the amount of remaining energy is small and is stored in second I-V characteristic storage means 4, and SOC arithmetic operation means 7 for calculating an SOC (charging state) of the battery in the first state by using the first and the second battery voltages calculated.