When you work with car batteries or regular household batteries (including 9 V batteries), they tend to accumulate dirt and sometimes corrode. Battery debris can cause acid leakage in the battery and also reduce its useful life. Clean the battery by washing and scraping dirt and corrosion from the connection points. Keeping the battery connections clean will make the battery last longer and save costs.
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Method 1 of 2: Cleaning Corrosion in Car Battery Terminals
Step 1. Open the hood and assess the condition of the battery
You do not need to remove the battery from the vehicle to inspect and clean it. To access the battery, open the hood and locate it. Usually, the battery is on the front left side of the engine block. Pay attention to the overall condition of the battery. If you're sure the battery isn't cracked or leaking, you can start cleaning it.
If there is a crack in the battery, replace it completely. Visit a repair shop and buy a new battery
Step 2. Assess the degree of corrosion on the battery and cables
Lift the plastic cover over the battery and set it aside. You will see a terminal/clamp interface on the battery. Check for excessive wear or corrosion of battery cables and clamps. Corrosion appears as gray-white deposits around one or both poles of the battery. If the cables and clamps are only lightly corroded or if they have little deposits, read the instructions below to find out how to clean them.
If the damage is severe enough, it's a good idea to completely replace the cables and associated clamps to prevent future problems
Step 3. Remove the negative and positive clamps on the battery cable
Before cleaning the battery, you need to disconnect it. The trick, loosen the bolts on the clamp using a wrench. If so, remove the negative clamp with the "-" symbol first. Only after the negative clamp is removed can you remove the positive “+” clamp.
- The clamp can be difficult to remove, especially if there is a lot of corrosion. You can also use pliers to remove the clamp.
- If you need to use pliers, be careful not to touch the frame of the car (or anything metallic) and the battery while working to prevent a short circuit.
Step 4. Make a cleaning agent from baking soda and water
Mix 2-3 tbsp. (30-45 ml) baking soda with 1 tbsp. (15 ml) distilled water in a small bowl. Stir the ingredients with a spoon to make a thick paste. Keep stirring until all the baking soda is completely dissolved in the water.
Baking soda is alkaline, which means it can neutralize corrosion from battery acid
Step 5. Apply baking soda paste on the battery connection
Dip an old toothbrush or slightly damp cloth in the baking soda paste. Rub the paste on the corroded or dirty parts of the battery. If the paste has smeared on the battery, you will see air bubbles and foam due to the corrosion reaction. Wait at least 5-10 minutes for the baking soda to react enough and loosen the corrosion.
Be careful when applying the paste. While baking soda is fairly safe, you should still keep it safe from contact with other car components
Step 6. Scrape off corrosion deposits with an old butter knife
If the deposits on the battery terminals are heavy, use a sharper old butter knife to scrape them off. Hold the blade at a 45 degree angle and press down along the surface of the battery to scrape the corrosion away. After you have removed most of the corrosion deposits, use a wire brush or steel wool to remove any remaining deposits.
- Put on dishwashing gloves before cleaning the terminals, especially if you scrub corrosion with steel wool. Hands will be in direct contact with potentially caustic materials so wear vinyl gloves for maximum protection.
- There are "battery pole" and "battery clamp" brushes that can be purchased at a repair shop, but are usually not required. An ordinary steel brush will suffice.
Step 7. Rinse the battery with water when it has been brushed clean
When the baking soda paste has stopped foaming, and there are no more heavy deposits to scrape off, you can rinse off the corrosion dust and drain the baking soda from the battery. Pour about 2 cups (470 ml) of distilled water over the battery and the positive and negative terminals.
- Be careful not to let the baking soda get into the battery vents as the baking soda can neutralize the battery acid and shorten the battery life.
- These vents are located on the side of the battery and are connected to a long vent hose that directs harmful gases away from the vehicle cabin.
Step 8. Wipe the terminal clean with a dry cloth
Drain the entire battery before reconnecting it to the vehicle. Make sure the terminal is completely dry by wiping the rag 2-3 times on the battery. Make sure you use a clean rag that isn't greasy or dirty!
Do not use kitchen paper for this step. The tissue will tear which may be left in the battery terminal
Step 9. Rub Vaseline on clean terminals to prevent corrosion
Dip 2 fingers in the vaseline tube and apply a thin layer to the positive and negative terminals. Make sure you're still wearing your vinyl gloves before doing so. Vaseline, which is a hydrophobic petroleum jelly, will prevent further corrosion from occurring in the future.
If you don't have Vaseline at home, buy it at a supermarket or pharmacy
Step 10. Reattach the 2 clamps to the battery
To complete the cleaning, you will need to re-attach the previously removed clamp to restore power and keep the battery from moving. Replace the positive clamp on the battery first by tightening it using a wrench. Once it's firmly in place, you can reconnect the negative clamp to the negative terminal on the battery. Return to use the wrench to close it.
Once the clamp is in place, replace the rubber or plastic shield covering the clamp/terminal connection
Method 2 of 2: Cleaning Home Battery Terminals
Step 1. Check the battery terminals for corrosion
Open the cover of the device to access the battery compartment. Open the battery cover to check the corrosion level of the battery. Check for leaks and cracks in this old battery. Mild corrosion will appear as black dots, while severe corrosion will appear as gray-white spots around the poles or terminals of the battery.
- Immediately dispose of a battery that is leaking acid (and not simply corroding). The chemical leaking from the battery is likely potassium hydroxide, which is a strong base. Make sure you wear skin and eye protection before cleaning the battery case as potassium hydroxide is highly caustic.
- If the device is powered by more than 1 battery, there is a possibility that 1 battery is corroded and the other is fine. Take the uncorroded battery and set it aside. This battery will be re-installed when the corrosion on the battery and the case has been cleaned.
- The cleaning method with baking soda can only be applied to corrosion around the terminals, and not to leaking batteries.
Step 2. Mix baking soda and water to make a cleansing paste
Make a cleaning agent by mixing 2-3 tbsp. (30-45 ml) baking soda with 1 tbsp. (15 ml) of water. Stir the ingredients with a spoon until they form a thick paste.
Make sure the baking soda does not come into contact with other electronic components, such as electrical devices that house cleaned batteries
Step 3. Rub the corrosion on the battery terminals with a cotton swab
Dip a cotton swab in the baking soda mixture. Rub the cotton swab covered with the baking soda paste into the battery connections and the 2 terminals on the ends of each battery. If you've rubbed off the baking soda, you'll see bubbles and foam because the soda reacts with corrosion. Leave it for about 5 minutes.
- Put on vinyl gloves before cleaning battery corrosion. When cleaning, make sure your skin does not touch the white deposits as they are caustic and can burn the skin.
- Be careful not to let water touch the electronic components when cleaning corrosion.
Step 4. Wipe the battery and its case with distilled water and a cotton swab
When the corrosion stops bubbling and there are no more deposits to scrape off, you can rinse the inside of the battery case. Dip a cotton swab in a cup of distilled water. Then, pat the cotton swab back and forth along the inside of the battery case. This will rinse off any remaining baking soda and clean the battery connections so they're ready to receive electricity.
- Be careful not to expose the electrical components to water because they can be damaged.
- Wait 15-20 minutes for the battery and case to completely dry.
Step 5. Put the cleaned battery back into its case and attach the cover
Now that the battery is clean, you can put it in a clean container too. If you previously set aside an uncorroded battery, now you can put it back in. If so, close the case or replace the battery case cover. Press down on the plastic cover until it snaps into place.
