The plateau portion 20 of the lid 15 includes a first projecting portion 21 projecting between the positive electrode terminal 17 and the negative electrode terminal 16, and a second projecting portion 22 extending in parallel with the arrangement direction of the positive electrode terminal 17 and the negative electrode terminal 16. The plateau portion 20 includes a handle 23 for a user of the lead-acid battery 100 to grip the lead-acid battery 100.

The second projecting portion 22 is provided with water filling ports at positions corresponding to the cell chambers, and the lid 15 is provided with vent plugs 18 for sealing the water filling ports. In the example shown in FIG. 1, the lid 15 includes six vent plugs. When water addition is performed on the lead-acid battery 100, the vent plugs 18 are removed and refilling liquid is added.

A vent hole 24 is provided in a side surface of the second projecting portion 22 of the lid 15. The vent hole 24 is connected to an exhaust path (not shown) provided in the lid 15, and discharges gas generated in each cell chamber to the outside. In addition, the vent hole 24 is provided at an end portion in the arrangement direction in which the vent plugs 18 are arranged when the lid 15 is viewed from the top. In other words, the vent hole 24 is provided such that the vent plugs 18 and the vent hole 24 are on a straight line.

[Schematic Configuration of Vent Plug 18]