family auto mechanics - helping you find the problem

family auto mechanics - helping you find the problem

How To Clean Auto Battery Corrosion From Terminals

by Herman Mills

If you have trouble starting your vehicle, or running accessories, it may be time to clean the battery terminals. Corrosion appears as a white, fuzzy-looking crust on the terminals, occurring from discharged hydrogen for charging, or the terminal and cable are different metals. Follow these steps to clean corrosion from battery terminals.

Prepare to Clean the Battery

To clean battery terminals, gather:

  • work gloves
  • rag or paper towels
  • eye goggles
  • battery cable wrench or insulated wrench  (5/16 or 3/8) 
  • battery brushes or old toothbrush
  • locking pliers
  • dark cola
  • baking soda
  • petroleum jelly
  • battery terminal cleaner (optional) 

Park the vehicle on a flat work surface, and let the motor cool before you work on it. Plan to clean the battery before you drive or early in the morning to keep parts from getting too hot. Prop the hood, and locate the battery box in the engine compartment, or refer to your manual.

Use the battery terminal wrench to loosen battery cables by turning the nut to the left, beginning with the negative cable. A side-post battery commonly requires a 5/16 wrench.  

Push the cables out of the way, not letting them touch. If the cables are hard to remove, use locking pliers. Inspect the battery housing for damage and cracks. When you reconnect cables, hook up the positive cable first.

Clean with Baking Soda

Sprinkle enough baking soda to cover the two battery terminals and cable ends, and use the toothbrush or battery brush to work it on the surface. If you prefer, mix baking soda and water in a small container or spray bottle until a paste forms, and dip the brush into the mixture.

Add two tablespoons of hot water to the powder, which should cause bubbling in one minute. Brush the terminals and cable ends again, then rinse with cool water. Don't reconnect the cables until everything dries.

Pay special attention to cleaning the inside of the O-ring, where most corrosion occurs. After the terminals and cable ends dry, rub a thin layer of petroleum jelly on them to prevent corrosion.

Remove Corrosion with Dark Cola

Slowly pour a small amount of dark cola over the cable ends and connectors. Let the cola stand several minutes, so it has time to bubble, and pour some more cola if it hasn't bubbled in one minute. 

Brush the corrosion using the toothbrush or battery brush. Wet a paper towel or rag, and wipe the connectors and cable ends until no materials remain, then let it dry complexly. A battery terminal cleaner can be used for stubborn corrosion. For more information, contact a company like Straightline Collision.


About Me

family auto mechanics - helping you find the problem

As the son and grandson of mechanics, I spent much of my child hood under the hood of many cars. I have listened and learned about so many different problems and how to repair them effectively. I created this blog to cover as many car problems as possible without overwhelming readers. You will find tips for troubleshooting, advice for when to take it to a professional and suggestions for when to stop driving the car or truck immediately to prevent further and more costly damage. We hope that you find all of this information helpful and useful, allowing you to have a great running car.