Lithonia Lighting ELB 1P201N2 M50 Quantum 1.2V Exit Replacement Battery For use with Lithonia Lighting quantum exit sign (lqm el n) Delivers 90 minutes of power to emergency lamps 7 to 9-year expected life, nickel-cadmium battery 2-State constant-current charge maximizes battery life and automatically recharges after battery discharge Installation takes just a few seconds when replacing Old batteries