How To Clean Car Battery Terminals?

Battery terminals, the electrical ports where the charger is connected, have evolved in design in recent years. This makes cleaning a little intimidating for some, especially for those who have minimal technical knowledge about automotive. So, how do you clean car battery terminals exactly?

Cars commonly feature three terminal types, all of which essentially follow the same cleaning setup and precautionary measures. At this point, you will be following the same instructions in this article, regardless if you are using a JIS type, an SAE post, or a side post. Readers from Europe might be more familiar with the L-shaped post, but the procedures are basically the same.

Cleaning only takes a few minutes, and you can do that by following these five easy steps. They might be simple, but these steps have been proven safe and effective for all types of cars as tested by pros with years of experience in the automotive industry.

What You Need:

  • a pair of rubber gloves (dish gloves will do)
  • a cup of clean water
  • additional water for rinsing
  • small brush (old toothbrush will do)
  • clean cloth
  • baking soda (which is the main cleaning agent)

Using petroleum jelly or metal lubricant is optional, although it is highly recommended to prevent corrosion. Nonetheless, you can use either as lubricant for any car model as an additional precautionary measure.

Be sure to gather all necessary materials before starting as leaving the terminals exposed halfway through cleaning is prone to accidents, especially if you have kids around.

How To Clean Car Battery Terminals? | Easy Steps


Step 1

Prepare the cleaning agent by adding a tablespoon of baking soda into a cup of warm water. Mix them well until you no longer see residues.
Be sure to turn off your car engine and to wear your gloves at this point to avoid unexpected electrical surges and skin burns.


Step 2

Unfasten the nut, but do it slowly if you see corrosion at the root to avoid breakage. You might need a 5/16-inch wrench or a 3/8-inch wrench, depending on your car model.

Once done, remove the clamps by starting with the negative cable before proceeding with the positive cable. Not removing the battery cables in correct sequence will only cause short in the system and pressure build up inside the case, leading to cracks and deformities, giving you more problems to worry about.
There might be some difficulty in pulling out the nuts if it has been quite some time since the last cleaning. If you experience this, you may want to twist and pull them together simultaneously.
Once all nuts and clamps are out of the way, start inspecting the terminal for any leakages, physical damages, corrosions or grime buildups. You may proceed with brushing if you fail to see any damages. Remember that cleaning is only meant to remove corrosion and grime, and not repair any irreversible damage.


Step 3

Pour a quarter of the cleaning solution into a separate cup, which is where you will dip the brush while cleaning. Replace the solution once it starts getting too dirty with residue.
Using the brush that has been soaked in the solution, gently scrub the posts and clamps in single direction until all corrosion and grime buildups are completely removed before moving on to another side. You may soak the brush as often as you want, but avoid directly pouring the solution to the terminal as sudden temperature changes might trigger pressure buildup.
Once clean, proceed to washing the terminals of any baking soda residue before dabbing the surfaces with clean cloth. You may want to use a sprayer bottle for more precise rinsing but if not available, gentle pouring can also be done.


Step 4

After drying, apply petroleum jelly to the clamps and posts. This will drastically improve the connection while also adding an additional layer of protection against corrosion. You can also buy a specially-made lubricant and protection spray for car battery terminals if you prefer to use higher-grade materials (some studies say that using ordinary household solutions suffices in prolonging battery life, though).


Step 5

Finally, start reattaching the clamps but this time, by starting with the positive cable before proceeding with the negative cable. You do not want short circuit at this point. Tighten the nut after reattaching each clamp.
Start your engine and observe if there are any problems with the electrical system. You are good to go if there are none.

You may watch this YouTube video for a clearer demonstration of the cleaning process using the same solution:


The aforementioned procedures are applicable for maintenance in your own garage. However, emergency cleaning might be needed if you are on the road or somewhere far from any service provider. In such case, you can use any regular carbonated drink or soda instead of baking soda as cleaning agent.
All you have to do is to follow the same detaching procedures for the cables, gradually pour the soda on the car battery terminal. Leave it there for two to five minutes. Dry and proceed to reattaching the parts again. You still have to do the regular cleaning once home, though, as this is only meant to be a temporary solution.


Cleaning is never a replacement for repairing and replacing car batteries. There are times when the only thing you can do is to replace the entire battery with a new one. As such, be particular with leakages, deformities in the battery case, cracks in any plastic or metal surface, and swelling, as these signs show that replacement is already inevitable.
Be particular with the detachment and attachment of battery cables as well, as most damages from cleaning come from incorrect sequencing. Not doing so may be dangerous to yourself and to your car.

Final Word

To summarize, cleaning your car battery terminal with ordinary household products suffices for maintenance. There is really no need for professional services on this matter, as more serious battery problems can no longer be fixed with mere cleaning anyway.
A baking soda-water-petroleum jelly combo truly does wonders in your car battery maintenance. However, it is also important to know when to clean and when to replace car batteries as some corrosion may come with physical damages and leakages that can no longer be fixed.
What you have to do now is check if your car battery terminal needs some cleaning and stash the materials in your car for emergency use. Moreover, do not hesitate to ask for professional help should you find other more complex concerns with your car’s electrical system, battery and engine.

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