Duracell Rechargeable Pre-Charged NiMH batteries let you charge hundreds of times, helping you save money. With its Ion Core technology you get amazing power in every battery. Plus, they come pre-charged & ready to use. They are guaranteed to last for 10 years (or up to 400 recharges, whichever comes first) in storage & they will hold a charge for up to one year when not in use. These powerful NiMH batteries work in any NiMH charger & you can recharge them up to 400 times. Battery Type: NiMH Rechargeable; Battery Size: AAA; for Use With: Everyday Electronic Devices; Battery Capacity: 800 mAh.