"These Duracell Rechargeable AAA NiMH Batteries batteries are charged and ready to use right out of the package. Ideal for use with cameras and more. Battery Type Cylindrical rechargeable, Batteries qty. 4, Volts 1.2, Battery Amp/Hour 850 mAh, Temperature Range F -14-122. Last up to 5 times longer than alkaline batteries Will hold a charge for up to one year while not in use NIMH technology has no memory effect, allowing it to be recharged hundreds of times Works with most NiMH battery chargers"