Lead-acid battery and method for producing lead-acid battery

A plate group in which a negative electrode substrate in which a negative electrode active material and a positive electrode active material are filled in a lattice substrate and a large number of positive electrode substrates are laminated via a porous retainer mat is accommodated in a battery case, and an electrolytic solution is injected into the battery case. The lead plate battery is impregnated with the electrolyte solution and subjected to chemical conversion treatment, and is a lead storage battery having a charging rate of more than 70% and less than 100%, and is used in an intermediate charging state, and the electrolyte solution contains aluminum ions and selenium ions. Including at least one kind of titanium ion.