Duracell Rechargeable Precharged NiMH Batteries let you charge hundreds of times, helping you save money. With its Long-Life Ion Core technology you get amazing power in every battery. Plus, they come precharged and ready to use. They are guaranteed to last for ten years (or 400 recharges, whichever comes first) in storage and they will hold a charge for up to one year when not in use. These powerful rechargeable batteries work in any NiMH charger.