Duracell Rechargeable Pre-Charged NiMH batteries let you charge hundreds of times, helping you save hundreds of dollars. With its Long-Life Ion Core technology you get amazing power in every battery. Plus, they come pre-charged and ready to use. They are guaranteed to last for 10 years, or 400 recharges, whichever comes first. With Duralock Power Preserve Technology, they’ll hold a charge for up to 1 year when not in use. These powerful NiMH batteries work in any NiMH charger and you can recharge them up to 400 times. With a long-lasting charge that requires fewer recharges, Duracell Rechargeable batteries really do set themselves apart from the rest.