Automotive batteries can be dangerous to work around. Such batteries contain a "wet" chemical reactor where electricity is stored. Due to its chemical composition, the reactor generates hydrogen gas that can collect along the top of the battery, creating a potential for explosion if ignited. Clean battery terminals can reduce the amount of hydrogen around the top of the battery, and correct removal and replacement of the terminals will prevent unsafe sparks.
Put on protective eye goggles, a long-sleeve shirt and leather gloves to reduce the chances of personal injury while working on any automotive battery.
Remove the black negative battery cable first, and secure it in a location where the cable clamp will not come into contact with metal or the positive post of the battery.
Remove the red positive battery terminal last, and secure it in a location where it will not come into contact with either of the battery posts.
Place 3 or 4 tbsp. of baking soda into 12 oz. of water. Gently pour this solution over one battery post at a time and wait for the solution to begin bubbling as it neutralizes any corrosive acid accumulation on and around the post. Use a wire battery-post brush to brush away the neutralized material, then flush the area with baking soda solution until there is no longer any foaming action. Perform this same cleansing step for the other battery post and for both terminals.
Reconnect the terminals to the battery posts by connecting the red positive battery terminal first, making sure the negative terminal isn't touching any metal of the vehicle. Tighten the positive terminal until just slightly more than hand-tight, then connect the black negative battery terminal to the negative post of the battery, tightening it just more than hand-tight.
