A load leveling battery (122) comprising an electrolyte that includes a cerium zinc redox pair wherein preferred electrolytes are acid electrolytes, and most preferably comprise methane sulfonic acid. Contemplated load leveling batteries (122) have an open circuit voltage of at least 2.4 Volt per cell. Such batteries are useful at power grid substations (120) and commercial and industrial applications were large amounts of power are used. Preferred capacity is at least 100,000 kWh, more preferably 250,000 kWh.