How to Clean Corrosion from Your Car Battery

Every automobile battery will develop corrosion on the battery terminals and posts as they age. Small amounts of vapor from the acid inside the battery will bond to the terminals and crystals will grow. Mostly, they will be white with some blue mixed in for good measure.

The corrosion will give you problems if it is not removed.

If they are allowed to grow long enough, the corrosion will weaken the connection between your car and the battery. Eventually, either your battery will lose its charge because the power from the alternator cannot reach the battery to recharge it, or the connection will become bad enough to prevent the power from leaving your battery to start the car. Regardless of which way it happens, your car will not start.

Cleaning a battery is a relatively simple job.

You will need a wrench or two to remove the battery terminals from the posts or to unscrew the terminals out of the side of the battery. Side attachment batteries do not usually corrode as easily or as rapidly as top post batteries. With the correct wrenches, loosen the bolts that hold the terminals onto the battery posts. It is always a good idea to remove the negative side first. This lessens the chances of a spark and possible explosion from acid vapors surrounding the battery. You know they are there because your battery has corrosion.

After the terminals are off, it is time to clean them and the battery posts.

Brush off the terminals and the posts with a rag or stiff brush. This is just to get the majority of the corrosion removed. Use a battery cleaning tool to complete the job. This device can be purchased relatively cheaply at any auto parts store. Most department and discount stores have them, too.

One end is open with steel brushes inside. The other end has a cap that covers a round steel bristled brush. The male end is used to clean the terminals. The female end is designed to clean the battery posts. Run the brush through the terminals and brush the exterior, also. Use the other end to slip over the posts. Twist is two or three times on each post. This will usually do the trick. When you are finished, the posts should be a shiny almost silver color.

It is time to reconnect the terminals to the posts.

Attach the terminals to the posts beginning with the positive terminal. You will need to get them pretty tight. However, remember that the terminals are made of lead. This soft metal will bend instead of getting tighter after a certain point. So, when the terminal is too tight to turn with your hand, it is probably tight enough.

Add a little grease or oil to seal the posts and terminals from the acid vapors.

There are commercial products to do this job. If you prefer them, it is alright. Oil or axle grease is just a lot cheaper and does the same thing. However, sealing these terminals and posts will help delay the need for future cleanings and loose connections.