The battery is the pulse of your car, supplying power to everything from your engine and electrical systems to your cabin lights and radio. So it’s understandable that you would be concerned if you saw corrosion around the terminals of your battery or the wire connections. Fortunately, battery corrosion is not always a sign of a bad battery. However, it does mean that your battery needs to be recharged more often and can result in a shorter lifespan than expected.
Corrosion occurs when metal reacts with the environment around it. This deterioration can affect the form, size and permeability of the metal. Different metals corrode at different rates and are more or less reactive to environmental conditions, such as temperature and the gases that surround them. Some metals corrode faster than others, for example pure iron rusts easily whereas stainless steel, which combines iron with other alloys, is more resistant.
The corrosion that can develop around your battery’s terminals comes from sulfuric acid vapor that escapes from the vent holes on the top of the battery and also hydrogen gas escaping through the wire connection points to the metal clamps. This vapor can then mix with other gases under the hood, the copper of the terminal posts and cable ends, and moisture to create a corrosive mixture.
This corrosive mixture will build up over time and may even leak onto the ground. This is not only unsightly but can cause serious damage to the surrounding area, including the engine and other electrical systems of your vehicle. The good news is that it is easy to prevent corrosion with a little maintenance.
You should look for a greenish blue or white substance on the battery and around the metal connections. This consists of carbon, lead and other components of the battery that have reacted with sulfates of the lead in the battery, forming what is known as sulfation. When this buildup reaches the terminals of the battery, it can prevent the electric charge from passing through them efficiently and your engine or other accessories may begin to struggle or shut down completely.
Corrosion can happen to any type of metal, but it is more common on metals with low melting and boiling points, like the common lead-acid battery in your automobile. The corrosion may be more or less noticeable depending on the amount of sulfates that are present. If you have very high levels of sulfates, the corrosion will be more prominent and will probably cover the entire battery.
The best way to avoid this is to clean your battery regularly and check for signs of sulfation. You can do this by using a cleaner that you can buy at your local auto parts store. You can also replace your lead-acid battery with a lithium battery, which is not only less prone to corrosive buildup but will also provide more energy and last longer than a traditional lead-acid battery.