Abstract: The following relational expression holds among: the number (L1) of first inner ribs (320) extending toward a first vertex-side portion (A11) between a position of a first vertex (C1) and a position separated therefrom by a first reference length; the number (M1) of first inner ribs (320) connected to both a specific second inner rib (310V) and the first vertex-side portion (A11) of a first frame rib (210L); the number (P1) of second inner ribs (310) extending toward a first vertex-side portion (A21) between the position of the first vertex (C1) and a position separated therefrom by the first reference length; and the number (Q1) of second inner ribs (310) connected to both a specific first inner rib (320V) and the first vertex-side portion (A21) of a second frame rib (220D), (M1/L1)>(Q1/P1)

Abstract: A negative electrode material of a negative electrode plate of a lead-acid battery includes an organic expander having a S element content of 3000 ?mol/g or more.

Abstract: A negative electrode material of a negative electrode plate of a lead-acid battery includes an organic expander having a S element content of 3000 ?mol/g or more.

Abstract: A positive electrode plate for a lead-acid battery includes: a punched grid having grid crosspieces; and a positive electrode material. A corner portion of the grid crosspiece of the punched grid in a cross section perpendicular to an extending direction of the grid crosspiece is deformed, and a density of the positive electrode material after being subjected to formation is 4.1 [g/cm3] or more.