How to clean battery terminals on your car? This question will rise up once you take a look at the car battery and see a yellow-green, mold-like substance on the battery terminals (also known as battery terminal corrosion).
This is a sure sign that you have to take some action as soon as possible and get rid of this problem.
In this article you’ll find out how to clean battery terminals by yourself, in a short amount of time and with cheap items which you probably already have around the household.
The lower mentioned methods are based on the same principle only the means of doing it are different (end result should be clean battery terminals).
So, take a look, pick out a method that best suits you and get rid of that nasty battery terminal corrosion. It’s a DIY task for sure, so even drivers with less experience around cars should be able to do it easily.
HOW DOES BATTERY TERMINAL CORROSION BUILD UP ANY WAY?
Since I’m not a chemist, I’ll give a laymen explanation:
Corrosion on the battery terminals appear due to a chemical reaction where hydrogen gas is released from the acid in the car battery.
The gas joins up with other elements in the air thus causing the corrosion build-up.
If you have the time, click here for a more professional and thorough explanation on Wikipedia.
WHY SHOULD YOU CLEAN BATTERY TERMINALS AS SOON AS POSSIBLE?
Lots of drivers tend to neglect this problem leaving the battery terminals corroded for months, although this task only takes a couple of minutes.
The main problem here is that the battery terminal corrosion may eventually cause loss of contact between the battery and the car installation. Also, the recharging process from the alternator to the battery can be disrupted.
This will eventually lead to problems like:
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Complete loss of electrical power due to loss of contact
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Problems with the car electrics or electronics
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Weaker battery output due to lower battery recharge
In my opinion, the most severe problem is a complete power cut-off which can happen in a moment’s notice due to corroded battery terminals.
My main point here is that because of a few minutes of simple work, you could eventually end up not being able to start your car.
WHAT WILL YOU NEED TO CLEAN BATTERY TERMINALS?
The list stated below is pretty long, but don’t worry, you’ll just need some of these things depending on the method you choose. This list is just to give you an overview.
You’ll need:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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A smaller plastic bowl
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Some baking soda
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Table spoon
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Can of Coke
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Trigger spray bottle
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Toothbrush
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Some cloth or paper towel for wiping
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Sandpaper
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Pliers
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Round file
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Wire brush
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Lithium grease or WD-40 spray
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Protective gloves (rubber or disposable would be best)
SAFETY PRECAUTIONS
You should make these safety precautions before beginning:
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Turn the car off and remove the key from the ignition.
This is necessary for avoiding accidental starting of the car or leaving the ignition on.
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Before disconnecting the battery, leave the drivers side window or door open. This is a safety precaution in order to avoid an accidental lock down of the car when you disconnect the battery. It shouldn’t happen, but better safe the sorry.
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Disconnect the car battery before you start
This is very important and this way you’ll save both yourself and your car from any kind of trouble.
If you start doing this while the battery is connected, you’re at risk of causing an accidental short-circuit which can both cause you injuries and damage to the car electrics and electronics.
ALWAYS remove the minus (-) battery terminal first; this way you’ll surely avoid causing an accidental short-circuit by touching the car body or frame (like with a wrench, for instance).
Also, be careful not to accidentally cross connect the battery terminals if you’re going to use a simple metal wrench that’s not isolated on any side.
After removing the minus clamp, remove the plus (+) battery clamp.
Use a wrench or ratchet with a matching socket. Usually the battery clamps are held in place by a 8, 10 or 13 millimeter nut.
Some cars have a “pinch” system for tightening the clamp (you just lift a small lever on the clamp and it comes off). This case is even better as you won’t need any wrenches, ratchets or sockets at all.
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Use protective gloves
The gloves will protect your hands from the corrosive substance as it is pretty aggressive.
I mean it won’t burn your fingers off, but if you do it bare handed, you will feel a small burning to the finger tips. It may be even worse if you have sensitive skin.
Regarding all the other items (baking soda, Coke, vinegar), they’re not aggressive so use them freely.
CLEAN BOTH BATTERY TERMINALS AND BATTERY CLAMPS
It’s not enough to clean just the surface corrosion on the battery terminals and clamps; that’s just half the job.
The point of these methods is to achieve good, clean contact between the inner side of the clamps and the battery terminals. This is a job well done.
So, once you disconnect the clamps from the battery terminals, make sure that both the inner side of the clamp and the battery terminal are squeaky clean, so to say.
CHECK FOR CRACKS OR DAMAGE ON THE CAR BATTERY AND CLAMPS
It would be good to also make a brief inspection of the battery casing and clamps.
Battery corrosion can also appear if there is a crack on the battery casing (battery acid will leak out or evaporate causing corrosion).
If you encounter this problem, change the car battery as soon as possible. If you want to see and learn how to change a car battery, click here for a separate article on that topic.
Check that the clamps are properly connected to the battery cables; any kind of crack, broken cable or else can cause trouble. Also, battery clamps are known to break (mostly due to over-tightening).
Broken or damaged battery clamps and connections should be replaced right away in order to avoid future problems.
HOW TO CLEAN BATTERY TERMINALS WITH BAKING SODA?
Using baking soda to clean battery terminals is one of the most popular and widespread methods.
It’s based on a chemical reaction where the solvent of baking soda and water “eats” off the battery terminal corrosion (again a laymen’s explanation).
What you’ll need for this method:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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Protective gloves
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Baking soda, small plastic bowl (about 200 ml in volume), toothbrush and tablespoon
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Some old cloth or paper towel
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Trigger spray bottle
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Lithium grease or WD-40 spray
Now for the procedure:
1. Fill the small plastic bowl with hot water.
2. Put one table-spoon of baking soda in to the water and stir it up.
3. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
4. Use the toothbrush to apply the baking soda mixture on both the battery terminals and clamps. Rub in as much as you can, make sure to clean the inner side of the clamps too. Leave the mixture for a couple of minutes to react to the corrosion.
You can also leave the clamps submerged in to the bowl with baking soda for even better effect.
5. Fill the trigger spray bottle with water and rinse the leftover baking soda and battery corrosion.
6. Wipe everything clean and dry out with a clean cloth or paper towel.
7. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly, don’t over do it so you don’t damage the clamps.
8. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO CLEAN BATTERY TERMINALS WITH COKE?
This method is considered somewhat of a hack and is also very popular.
It’s also used as a sort of emergency procedure. Coke is widely found almost anywhere so if you have to clean battery terminals on the road for instance, you’ll have a better chance of finding Coke than baking soda or vinegar.
What you’ll need for this method:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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Protective gloves
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Can of Coke
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Some old cloth or paper towel
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Trigger spray bottle (optional)
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Lithium grease or WD-40 spray
The procedure goes like this:
1. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
2. Protect the area around the battery so you don’t make a mess. I’ve used an old cloth and tucked it around the battery.
3. Open the Coke and pour some on to the battery terminals and clamps. On this part, you can even use a separate trigger spray bottle filled with Coke. This will perhaps reduce spilling it around. Leave the Coke to react to the corrosion for a couple of minutes.
4. Fill the trigger spray bottle with water and rinse the leftover Coke and battery corrosion.
5. Wipe everything clean and dry out with a clean cloth or paper towel.
6. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly, don’t over do it so you don’t damage the clamps.
7. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO CLEAN BATTERY TERMINALS WITH VINEGAR?
Vinegar is also a common household item and is pretty effective to clean battery terminals.
What you’ll need for this method:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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Protective gloves
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Small plastic bowl (about 200 ml in volume), some vinegar and a toothbrush
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Some old cloth or paper towel
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Trigger spray bottle
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Lithium grease or WD-40 spray
The procedure goes like this:
1. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
2. Pour some vinegar in to the plastic bowl (not too much, just to cover the bottom of the bowl).
3. Use a toothbrush or some cotton swab and apply the vinegar on to the battery terminals and clamps. Let the vinegar react to the battery corrosion. Apply to the inner side of the clamps also. You can leave the clamps submerged in to the bowl with vinegar for even better effect.
4. Fill the trigger spray bottle with water and rinse the leftover vinegar and battery corrosion.
5. Wipe everything clean and dry out with a clean cloth or paper towel.
6. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly, don’t overdo it so you don’t damage the clamps.
7. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO CLEAN BATTERY TERMINALS WITH SANDPAPER?
This is one of the least complicated methods but pretty effective nonetheless.
With this method all you’ll need is:
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Piece of sandpaper
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Cloth or paper towel
What you’ll have to do is:
1. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
2. Use the cloth and clean the corrosion build-up as much as you can, both on the clamps and the terminals.
3. Roll the sandpaper into cylinder shape (the grinding side of the paper is outside). Use it to reach the inner side of the battery clamps and sand until they shine.
4. For the terminals, roll the sandpaper the opposite way (so the grinding side of the paper is inside). Put the cylinder on to the terminals and turn around. You can also use the sandpaper as a belt. Do whatever is easier for you. Sand until the terminals are nice and shiny.
5. Wipe everything clean with a cloth.
6. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly; don’t overdo it so you don’t damage the clamps.
7. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO CLEAN BATTERY TERMINALS WITH PLIERS AND A ROUND FILE?
This method is also effective although you won’t get the same quality of cleaning as with baking soda and vinegar.
You’ll need:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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Protective gloves
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Pair of combined pliers and a round file
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Some old cloth or paper towel
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Lithium grease or WD-40 spray
The main point here is to use the pliers to clean the battery terminals and the round file to clean the battery clamps:
1. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
2. Use the cloth and clean the corrosion build-up as much as you can, both on the clamps and the terminals.
3. Spread the pliers and put them around the battery terminal. Firmly grip the terminal and turn the pliers left and right several times as much as the space around allows it. The pliers will act as a sort of grater and peel off the corroded surface of the terminals.
4. Take the round file and use it for the inner part of the battery clamps. Go around all the way until the inner part shines.
5. Wipe everything clean with a cloth or paper towel.
6. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly; don’t overdo it so you don’t damage the clamps.
7. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO CLEAN BATTERY TERMINALS WITH A WIRE BRUSH?
The last method is perhaps the least effective but is the fastest one to do. Here, you’ll probably just remove the surface battery corrosion and perhaps some on the terminals and clamps.
This method is best used in a combination with other previous methods (for instance removing the surface corrosion with a brush first and then applying baking soda, vinegar or else).
I would recommend to use this method if you don’t have any other means.
What you’ll need for this is:
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Wrench or ratchet with matching socket (most common are 8, 10 and 13 millimeters)
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Wire brush. In this case it would be good to use thicker protective gloves in order to avoid stings from the wire brush.
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Some old cloth or paper towel
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Lithium grease or WD-40 spray
The procedure is:
1. Take off the minus (-) battery terminal clamp first and plus (clamp) second. Use a wrench or ratchet with matching socket.
2. Use the cloth and clean the corrosion build-up as much as you can, both on the clamps and the terminals.
3. Scrub the corrosion off with the wire brush as much as you can. The terminals will probably be easier to reach but the clamps will be more tricky. Reach the inner side of the clamps as much as you can. Once more, watch your hands so the brush doesn’t sting you.
4. Wipe everything clean with a cloth or paper towel.
5. Connect the battery clamps, this time in reverse order. Plus (+) first, minus (-) second. Tighten the nuts firmly; don’t overdo it so you don’t damage the clamps.
6. Apply a thin layer of lithium grease on the terminals and clamps; a fingertip per each terminal should be enough. You can also use WD-40 spray (a couple of sprays per each terminal) but lithium grease would be better and more long-lasting.
HOW TO PROTECT THE BATTERY TERMINALS AND CLAMPS FROM CORROSION?
Just one more word on protecting the battery terminals and clamps for the future.
As previously mentioned, when you’ve finished cleaning the battery terminals, apply a thin layer of lithium grease or WD-40 spray.
The purpose of this is to isolate the battery terminals and clamps from the outer conditions and reduce the possibility of corrosion build-up again.
Lots of people skip this step and then again may face the same problem and again have to clean battery terminals.
I would recommend to use lithium grease rather than WD-40 spray. The lithium grease will “seal” the terminals better and be more long-lasting.
If you use lithium grease just apply a fingertip for every terminal. Spread the grease so it covers both the battery terminal and clamp.
For WD-40, just spray a couple of times on each terminal so a thin layer forms.
WHAT METHOD IS THE BEST?
Every method stated here is effective and will solve your problem.
Choose what suits you best and what you have around the household.
Methods with baking soda and vinegar will give the best results in term of quality removing the battery corrosion. On the other hand, using sand paper or a file will take less time and preparation.
To tell you the truth, a combination of these is perhaps the best.
An example would be to use a wire brush to clean the primary corrosion, then apply baking soda, vinegar or Coke. After that, you can use some sandpaper and additionally clean the clamps and terminals.
I hope you get the idea. The main point is to get a job well done, clean battery terminals the proper way and avoid future problems.
