Precharged for instant power, these Duracell AA nickel-metal hydride NiMH rechargeable batteries are ideal for high-drain devices such as digital cameras and GPS units. Unlike some other NiMH rechargeable batteries, these Duracell batteries are precharged and ready to use right out of the package. Batteries retain power up to 365 days while not in use and can be recharged hundreds of times take up to 5,000 photos over the lifespan of 2 batteries. NiMH batteries pose less threat to the environment as they do not contain the heavy metal cadmium found in nickel cadmium batteries. Packaged includes 4 AA rechargeable batteries recharge the batteries in a NiMH charger, sold separately.