Nickel-cadmium Metabo power tool batteries, also referred to as NiCad or NiCd batteries, are a type of rechargeable battery made using nickel oxide hydroxide and metallic cadmium. They are commonly used in household electric products, such as laptops, camcorders, cameras and power tools. Over time, rechargeable batteries lose efficiency, meaning the amount of time they can power a product, begins to decrease. Eventually they will die and need to be replaced. Freezing a battery is a way to help restore the efficiency of a NiCad battery.
Remove the NiCad battery from the electronic device.
Place the battery in a sealable plastic bag. Seal the bag.
Place the battery in the freezer for an hour.
Remove the battery from the freezer.
Tap the bottom of the battery or battery pack with the butt end of the screwdriver for a minute. Freezing the battery crystals makes them more fragile. The vibration caused by the hitting makes the crystals break apart. This can help restore function to the Firestorm power tool battery crystals, allowing them to hold a charge for a longer period of time.