To suppress the deformation or breakage of a battery jar by elongation of a positive pole plate, and short circuit between the positive electrode side and the negative electrode side.
An expanded metal grating is used in a positive electrode plate 1 to constitute an pole plate group 4, a group pressure of 20-50 kg/dm2 is applied to the pole plate group 4, and a ratio of the length of a lateral diagonal line to the length of a vertical diagonal line in a grating square in the expanded metal grating is set at 1.07-2.04. The positive pole plate 1 is thus elongated in a vertical direction so as to restrict the deformation or breakage of a battery jar, and an acid-resistant resin insulation member 6 made to be interposed between an upper part of the positive pole plate 1 and a negative electrode shelf 5 to prevent short-circuiting between both electrodes.
IDE MASAYUKI
NAKAYAMA TAKURO
INOUE TOSHIHIRO
