Disclosed is a lead acid battery including: a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and an electrolyte containing sulfuric acid. The negative electrode includes a negative electrode active material, and a negative electrode grid that supports the negative electrode active material. The negative electrode grid contains tin in an amount of 0.1 mass % or more and 0.8 mass % or less. The electrolyte contains aluminum ions at a concentration of 1 mmol/L or more and less than 10 mmol L, and sodium ions at a concentration of 15 mmol/L or less.