A white, powdery substance can form on any type of battery. The white powder is corroded battery acid that can cause irritation if it comes in contact with your skin. Whether it is a watch battery or a car battery, removing the white, powdery substance from the terminal will keep the item working properly. When cleaning a battery, take great care to prevent harm to yourself and the battery.
Disconnect the negative and positive terminals from the battery. Use a wrench to loosen the fastener.
Move the terminals away from the battery to avoid an electrical contact.
Clean corrosion from the posts with a battery cleaner tool while applying pressure and rotating the tool.
Mix a solution of 1 cup of water and 1 tbsp of baking soda. Saturate an old toothbrush with the baking soda mixture.
Scrub the corrosion with the toothbrush until it is gone. Reapply the baking soda mixture to the toothbrush if needed.
Wipe the baking soda away with a clean, damp cloth. Allow the battery to air-dry or wipe dry with a clean towel.
Reconnect the terminals to the battery. Apply petroleum jelly to the area to prevent future corrosion.
Alternatively, pour a can of a carbonated soft drink on the battery corrosion to neutralise the white powder. Rinse the battery with a damp cloth and allow to dry.
Wear rubber gloves and safety glasses.