Turn off the engine and remove the key
Wear gloves and eye protection
Disconnect the negative terminal first
Disconnect the positive terminal second
Inspect the terminals for corrosion
Mix baking soda with water
Apply the mixture to the corroded areas
Scrub the terminals with a wire brush or terminal cleaner
Clean the battery posts and cable clamps
Wipe away residue with a damp cloth
Dry the terminals completely
Apply a thin layer of petroleum jelly or terminal protectant
Reconnect the positive terminal first
Reconnect the negative terminal second
Tighten the connections securely
Check that the terminals are stable and clean