by James Dreamer

Created on: November 30, 2010

Because automotive batteries contain acid, they are inherently destructive to all metal surfaces in their vicinity. Left unchecked, this toxicity will undoubtedly destroy not only the electrical connections, but also the mounting brackets and bolts.

Before going any further, it is important to note the safety issues when working around an automotive battery. Batteries store a great deal of energy. Shorting the terminals or wires connected to them will cause a powerful spark. Care must be taken to prevent any electrical mishaps, such as allowing your wrench to touch both positive and negative connections at the same time.

Battery acid does not only eat metal, it burns skin. Even touching the build up of corrosion on the terminals can cause burns. Wear rubber gloves or other protection when servicing these areas. Wash exposed skin immediately if it becomes contaminated. Also, batteries produce a mixture of oxygen and hydrogen which is explosive. Remember the Hindenburg? A smaller version of this disaster can occur under your hood if you subject the battery to a spark or open flame.

Before cleaning the battery terminals, it is best to consult the owners manual regarding any precautions to be taken prior to disconnecting the battery. There may be procedures to follow to preserve the data in the computer or stereo.

Whether your battery has top or side pole connections, always start by removing the grounded lead first. This is the lead connected to the body of the vehicle. On modern cars, it is usually the negative terminal. Do not let your wrench touch both terminals at once. After the ground is disconnected, remove the second connection.

If there is a great deal of corrosion, scrape it off with a knife or screwdriver or use a wire brush to remove it. A small amount of baking soda and water can be applied to neutralize the acid. Clean both the battery terminals and the connectors on the end of the cables. If any part is damaged or severely corroded, replace it.

Once everything is clean, use a knife to scrape the mating surfaces until they look new and shiny. This will insure the best electrical conductivity. Reconnect the positive (non-grounded) terminal first, followed by the negative (grounded) terminal making sure both are tightened securely.

If you want your newly cleaned terminals to last, for just a dollar or two you can buy a set of felt washers treated with chemicals to greatly reduce the rate of corrosion. I have had very good luck with these. They always seem to stop the build up of corrosion for the life of the battery. Simply install them on the battery posts before reconnecting the cables. Red on the positive and green or black on the negative.

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