Use Duracell® Rechargeable Nickel Metal Hydride (NiMH) Batteries in GPS and navigation equipment, two-way radios and other frequently used high-tech devices. Rechargeable NiMH Batteries last three to four times longer than standard alkaline batteries. Must be charged before use. Precharged Duracell® Rechargeable NiMH Batteries are ready to use right out of the package. Will hold a charge longer than standard NiMH rechargeables when not in use.