Abstract: Provided is a lead-acid battery where a positive electrode shelf and a negative electrode shelf are electrically connected to each other through a penetrating connection body including a welded portion filled in a penetration hole in a partition wall. A distance A between upper end surfaces of the positive and negative electrode shelves and a lower end portion of the penetration hole is 3-5 mm, a distance B between an upper end portion of the penetration hole and an upper end portion of the penetrating connection body is 3-5 mm, a distance C between the upper end portion of the penetrating connection body and a level of the electrolyte solution is 0 mm or more, and a height of the positive and negative electrode grid portions is 100 mm or more.

Abstract: Disclosed is a lead-acid battery including: a battery container; an electrolyte and an electrode plate group in the battery container; and a battery container cover that hermetically seals an opening of the battery container, wherein the electrode plate group includes a positive electrode plate including a positive electrode active material, a negative electrode plate including a negative electrode active material, and a separator interposed between the positive electrode plate and the negative electrode plate, the battery container cover is provided with a liquid port, a liquid port plug that closes the liquid port, and a sleeve that hangs down from the liquid port to a prescribed liquid surface height of the electrolyte, a sodium ion concentration contained in the electrolyte is 1 mmol/L to 90 mmol/L, and a specific surface area of the positive electrode active material is 5 m2/g to 9 m2/g.

Abstract: Provided is a lead-acid battery where a positive electrode shelf of one of two elements accommodated in cell chambers disposed adjacently to each other and a negative electrode shelf of the other element are electrically connected to each other through a penetrating connection body penetrating a partition wall, the penetrating connection body includes a positive electrode side member continuously formed with the positive electrode shelf and a negative electrode side member continuously formed with the negative electrode shelf, and the positive electrode side member and the negative electrode side member form a welded portion filled in a penetration hole formed in the partition wall for forming cell chambers by partitioning and are brought into close contact with a periphery of the penetration hole.

Abstract: A lead-acid battery includes an electrode plate assembly, a battery case, a positive electrode strap, a negative electrode strap, a positive electrode post, a negative electrode post, a cover, and an electrolyte solution. A negative electrode bushing provided in the cover and the negative electrode post together constitute a negative electrode terminal. A maximum value of a gap between an outer circumferential surface of the negative electrode post and an inner circumferential surface of the negative electrode bushing in the negative electrode terminal is 0.5 mm or more and 2.5 mm or less. A rib is provided in a lower part of the negative electrode bushing, and a minimum value of a protrusion height of the rib is 1.5 mm or more and 4.0 mm or less. A distance between a surface of the electrolyte solution and a lowermost portion of the negative electrode bushing is 15 mm or less.

Abstract: Disclosed is a lead-acid battery including: a battery container; an electrolyte and an electrode plate group in the battery container; and a battery container cover that hermetically seals an opening of the battery container, wherein the electrode plate group includes a positive electrode plate including a positive electrode active material, a negative electrode plate including a negative electrode active material, and a separator interposed between the positive electrode plate and the negative electrode plate, the battery container cover is provided with a liquid port, a liquid port plug that closes the liquid port, and a sleeve that hangs down from the liquid port to a prescribed liquid surface height of the electrolyte, a sodium ion concentration contained in the electrolyte is 1 mmol/L to 90 mmol/L, and a specific surface area of the positive electrode active material is 5 m2/g to 9 m2/g.

Abstract: A lead-acid battery includes an electrode plate assembly, a battery case, a positive electrode strap, a negative electrode strap, a positive electrode post, a negative electrode post, a cover, and an electrolyte solution. A negative electrode bushing provided in the cover and the negative electrode post together constitute a negative electrode terminal. A maximum value of a gap between an outer circumferential surface of the negative electrode post and an inner circumferential surface of the negative electrode bushing in the negative electrode terminal is 0.5 mm or more and 2.5 mm or less. A rib is provided in a lower part of the negative electrode bushing, and a minimum value of a protrusion height of the rib is 1.5 mm or more and 4.0 mm or less. A distance between a surface of the electrolyte solution and a lowermost portion of the negative electrode bushing is 15 mm or less.