The Duracell Optimum alkaline battery with the most groundbreaking Duracell technology ever has a new cathode system that provides up to 200% extra lifespan for some devices, or extra power for other devices. Duracell Optimum lasts longer than previous Duracell alkaline batteries in many devices with medium to high energy consumption. In other devices, Duracell Optimum provides more power and strength than other Duracell alkaline batteries so they work better.