All ACDelco SMF Batteries feature lead calcium expanded grids (Lead Calcium Technology) for improved resistance to corrosion, overcharging, gassing, water usage, self discharge and thermal runaway, all of which limit battery life in conventional lead acid batteries. DESCRIPTION Designed and manufactured to perform under toughest conditions Ultra high density plate material for high corrosian resistance Increased charge acceptance High depth of discharge lifecycle Maintenance free 3 Year Warranty