StayCharged AA rechargeables come fully charged and ready to be used right out of the package. Long-life Ion Core packs power in every battery. Recharge up to 400 times to save hundreds of dollars. Duralock Power Preserve Technology holds a charge for up to one year in storage so batteries are ready for your high-drain or frequently used devices, including video game controllers, high-powered flashlights, baby monitors and more. Each battery holds charge up to five times longer than ordinary rechargeable batteries when not in use. Batteries work in any NiMH charger.