How to Remove Corrosion from Your Car Battery

Most drivers have experienced the frustrations of a car that won't start. A weak or dead battery is a common culprit for vehicle performance issues. Sometimes, the battery has simply come to the end of its life. However, excessive corrosion buildup can also cause problems. This not only looks unappealing, but more importantly, it can hinder the battery's effectiveness. A little bit of corrosion on the battery terminals is normal and shouldn't be an immediate concern but neglecting this buildup will only cause it to get worse over time and possibly leave you stranded one day soon. Fortunately, there are some simple ways you can learn how to clean car battery corrosion. You may even be able to prevent this from occurring altogether.

The Problem With Corrosion

Most conscientious car owners will take great care to clean their vehicles and perform proper maintenance. Too many people forget about cleaning the battery terminals and eliminating corrosion. Corrosion buildup happens when the acid in the battery release hydrogen gas. Other materials in the environment will mix with this combination to cause the corrosion. Buildup more frequently occurs during the summer months when temperatures rise.

If you don't get rid of it, the corrosion can become an insulator and block the electrical charge from and to the battery. Initially, you may notice that it takes a few cranks to get your car going. Power may start to cut out to certain electrical systems. Eventually, this corrosion can leave your battery completely inoperable. This scenario could place a huge inconvenience on you and your family.

Get the Right Materials

Cleaning corrosion off your car battery terminals is not a complicated process. You don't have to take the car to a mechanic or rely on any advanced, complicated techniques to get your battery looking like new. You can either use one of our battery cleaning solutions or a combination of baking soda and water.

Using some baking soda and water, you can usually eat away all the corrosion on the terminals. To do this, start by assembling the essential tools and products for the job. You'll want some protective gloves for safety reasons. Next, grab a box of baking soda from your kitchen pantry along with some water. A toothbrush will be a handy tool to scrub the terminals. You should also get some old rags you don't mind getting dirty as well as some petroleum jelly.

Mix the Solution

The baking soda and water should be enough to do the job efficiently. Start with 1 tablespoon of baking soda to 1 cup of water, and mix it thoroughly until all the baking soda is blended in. If your vehicle’s battery has heavy corrosion, it may be better to use a specialized cleaner.

Shop Cleaning Essentials at AutoZone

How to Clean Car Battery Corrosion


Safety First

Never work on your car battery with the engine on. Shut it off, and then pop the hood and undo the cables attached to your battery. You won't have to look hard to spot any corrosion; it's a white-, gray- or brown-colored substance that can take over the battery terminals and spread throughout the battery. Don't try to do anything with your battery if you detect an acid leak or if the battery itself is swollen. Instead, let a professional take a look at it and remove it.


Start Scrubbing

To remove the corrosion from the terminals, take your brush, dip into the cleaning solution and begin scrubbing off the buildup. It may take considerable effort on your part to get rid of all of the corrosion. Obviously, the more buildup you find and the longer it has been there, the more challenging this step will be. Keep going until the terminals are completely free of any gunk.


Clean Off the Residue

You haven't quite finished your job yet. Next, you'll want to rinse off any remaining baking soda solution and leftover corrosion. Gently pour or spray a little bit of water over the terminals to flush anything out. You could use a damp rag as well. Then, dry the battery with an old towel or cloth.


Prevent Further Corrosion

A little bit of corrosion may be inevitable, but you can take some important steps to keep this nasty material away from your battery for the most part. Put a small amount of petroleum jelly on the terminals once they are dry. This will keep the connection strong going forward. Don't forget to reconnect the positive and negative cables before you shut the hood.


Test it Out

It's always a wise idea to crank on the engine and make sure the battery is working like a charm again. If cleaning the corrosion didn't seem to improve the battery's performance, you should head to your local AutoZone and consider picking out a new one.

Choosing a New Battery

Speaking of which, when it’s time to purchase a new battery, not any product will do. You want to find the right car battery so you can have peace of mind every time you start up your vehicle. Carefully research different batteries and which one will fit your needs best. There are three main features to pay attention to: cranking amps and cold-cranking amps, reserve capacity, and warranty. Cranking amps is a measurement of your battery’s power in temperatures of 32 degrees F and above, while cold-cranking amps measure the battery’s power when the temperature outside is below freezing. Consult the vehicle’s owner’s manual and purchase a battery with the recommended cranking amps. You’ll also want to purchase a battery that has a high reserve capacity, which allows your battery to provide power to the car even if you left a light on for a few hours. Meanwhile, warranties usually come in one, two or three years. It should provide free replacement during the life of the warranty.

When it comes to your vehicle, few things are more frustrating than dealing with a dead battery. If you follow these steps of how to clean car battery corrosion, you are much less likely to experience these annoying issues at an inopportune time.

Advice, how-to guides, and car care information featured on and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

FREE Loan-A-Tool® program requires returnable deposit. Please note that the tool that you receive after placing an online order may be in a used but operable condition due to the nature of the Loan-A-Tool® program.