checking the microphone and webcam

removing corrosion from battery compartment

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Step 9: Fixing Oxidised and Minor Corroded Terminals

I found this cool, vintage mike at the dump and wanted to try and get it going again. Initially I tested it not knowing that it needed an AA battery and thought it was probably something to do with the wiring. After un-screwing the case however, I discovered that it needed a AA battery to run. The battery had been in place for some time and the terminals were oxidised and had some minor corrosion damage. I could have replaced the terminals but decided it would be easier just cleaning them


1. Remove the old battery with a screwdriver and dispose of. Even though there was not as much damage and leakage as the first sample, I still made sure that I wore gloves and eye protection. They are considered safe to dispose of in the bin (imagine how many batteries get thrown away each day!) but there might be some local laws that require you to dispose of them in other ways

2. You can see in the images that there is a little corrosion and potassium hydroxide on the end of the terminal but that the terminal itself looks relatively unaffected structurally.

3. The brown streaks you can see running through the middle of the battery holder is actually glue that has discoloured over time, not corrosion

4. The next step is to neutralise the alkaline from the potassium hydroxide.

How To Prevent Battery Corrosion In Electronics

Purchase Energizer MAX brand batteries (shown above). They’re guaranteed not to leak.

[ Read: Batteries That Won’t Leak Or Corrode ]

And/Or, Remove the batteries from electronic devices that will not be used for a significant period of time.

This will prevent a slow discharge of the batteries and therefore prevent leakage when the batteries get low or go dead. Dead or low batteries are more likely to leak.


You might have a portable radio set aside for emergencies. Or maybe you haven’t used it for months and months. You should remove the batteries from the battery compartment to prevent a potential slow discharge and the resulting leak and corrosion.

Things You’ll Need

Disconnecting Your Car Battery Safely

  • Rubber, nitrile, or neoprene work gloves
  • Safety goggles
  • Wrench
  • Terminal spreader

Removing Car Battery Corrosion with Baking Soda

  • 1 cup (240 mL) water
  • 1 teaspoon (4.6 g) baking soda
  • Toothbrush or battery terminal brush
  • Clean, dry rag
  • Water hose or spray bottle
  • Petroleum jelly

Cleaning Corrosion on Alkaline Battery Contacts

  • Safety goggles
  • Rubber or nitrile work gloves
  • White vinegar or lemon juice
  • Glass or plastic bowl
  • Cotton swabs
  • Small blade or fiberglass pen
  • Silicone grease or petroleum jelly

Step 2: Removing Leaking Batteries

Don’t use your fingers to try and remove the batteries. The potassium hydroxide inside the battery can irritate your skin (I know as I’ve touched it before!). Potassium hydroxide is a caustic agent and is the chemical that corrodes the terminals and destroys the batteries. You may have also seen a feathery crystalline structure forming around the battery and terminal as well. This is potassium carbonate and forms when the potassium hydroxide reacts with carbon dioxide in the air.

For those who want to understand more about the chemical components inside an alkaline battery, please check out the following


1. Place a set of rubber gloves on and some safety glasses

2. Use a small screwdriver to pull the batteries out. The glasses here are very important as it is easy to flick small pieces of the corrosion whist pulling out the batteries.

3. Sometimes that batteries can be so corroded that they virtually weld themselves to the terminals. In this case you will need to use a large screwdriver and maybe some pliers to remove them. You’ll probably rip out the terminals as well so be careful you don’t pull any wires out at the same time

4. Dispose of the batteries in a plastic bag.

What Problems Does Car Battery Corrosion Cause?

Corroded battery terminals are one of the main culprits behind decreased battery life and performance. The corrosion interferes with the electrical current flow between the battery and the engine, and affects you in two ways. 

Not only does the car receive insufficient power, but the battery also won’t receive consistent recharging from the alternator either.  

What does this mean for your car?

A corroded battery terminal can prevent normal vehicle startups, which can result in you reaching out for those jumper cables every time you need to start your car.

Not ideal, right?

On top of that, unstable battery performance can lead to damage in other electrical components — like the air conditioning or even trigger issues on the vehicle’s onboard computer. And a  problem in the onboard computer can cascade to a variety of vehicle-wide complications. 

If you notice a corroded battery terminal or battery cable connector, the wisest thing to do is get it cleaned ASAP. 

How do you do that?

How to Clean Nickel Cadmium Battery Corrosion

Nickel Cadmium (NiCad) batteries are rechargeable. While less prone to leakage than alkaline batteries, they are more corrosive and the clean-up is handled differently.

  1. Remove and Dispose of Batteries

    Remove the batteries and dispose of them following waste guidelines in your community. Do not attempt to recharge batteries that have leaked.

    The Spruce / Sarah Lee

  2. Clean the Battery Case and Contact Terminals

    Sprinkle the inside of the battery case with dry baking soda to neutralize the potassium hydroxide in the corrosion. Empty the powder into a trash can for disposal.

    The Spruce / Sarah Lee

  3. Make a Baking Soda Paste

    To remove any remaining corrosion on the battery contact points of the device, mix a tablespoon of baking soda and a few drops of water in a small bowl. Dip a cotton swab in the mixture and rub the contact points. When no more residue is transferred, carefully dry the contact points with a paper towel.

    The Spruce / Sarah Lee

  4. Insert New Batteries

    Insert new batteries into the device and charge, if necessary.

    The Spruce / Sarah Lee

Energizer Guarantee

UPDATE, Energizer guarantees that these particular batteries will NOT corrode. I made the switch and can attest that none of them have leaked:

As of this writing, the best price I’ve seen for these batteries:Energizer MAX AA(view on amzn)

Energizer MAX AAA

5 Ways To Prevent Car Battery Corrosion

Here are methods you can use to prevent future corrosion of your car battery.

1. Felt Battery Washers

Battery terminal protectors like felt battery washers are one of the easiest solutions to protect your battery against corrosion. These washers are chemically treated to help absorb the vapor released at the battery post and last for several years to help keep the terminal clean. 

However, remember to apply some protective grease to the top of the washer and car battery terminal before installing. 

2. Protective Coating

You can use a protective battery grease or petroleum jelly on the battery terminal to prevent corrosion. Battery grease lasts longer than petroleum jelly when exposed to engine heat as it’s silicone-based. 

Alternatively, a rust inhibitor spray could also work just as well. 

3. Resolve Battery Charging Issues

If you suspect that your car battery is corroding because of undercharging or overcharging, bring your car to a mechanic to rectify the electrical fault. 

Charging issues could concern more than just the battery itself.

4. Copper Compression Terminals

Consider using copper compression terminals at your battery terminal ends. These are made from tinned copper and allow a full 360o contact with the battery cable, which helps distribute the electric current evenly and prevents corrosion.

5. Have A Regular Maintenance Schedule

Keeping up regular vehicle maintenance ensures that your car battery is routinely inspected and maintained.

While these five tips can help you prevent corrosion, it can still creep in over time and cause bigger issues.

When that happens, what do you do? 

How to Fix battery terminal corrosion

Now, when we know what causes the car battery corr

Now, when we know what causes the car battery corrosion, we need to know how to fix it. There are some different methods you can use to clean the battery terminals.

1. Baking soda – water solution

If you want to remove copper sulfate from the terminals, you will need some baking soda water solution and a brush. First, ensure that the car’s ignition has been turned off. Remove the battery terminals and use your brush to remove some of the corrosion.

Pour the baking soda solution and continue removing the corrosion with your brush. Once done, clean the terminals with some clean water. It is prudent to smear some wheel bearing grease on the terminals to prevent further damage. Some people may opt for petroleum jelly, but this does not last as long as grease.

2. Soda

Most of the soft drinks that we take have some carbonic acid in them. Pour some of the soda on the terminals and use a soft sponge to remove the residue. This works well in the absence of a baking soda-water solution.

3. Cleaning heavy corrosion

If your battery has excessive corrosion on the terminals, you will need to use a baking soda-water solution and an old toothbrush. Start by removing the battery terminals – the negative should be first. Mix your baking soda solution and place it in cups. Soak each of the terminals in the solution and let it soak for the next 20 minutes.

Scrub off the corrosive materials on the terminals. Pour in the soda solution and make a fresh one. Soak the battery terminals again while removing the corrosive materials. Clean the terminals with water and let them dry or wipe with a damp cloth. You can also use sandpaper to clean the terminals. Apply some grease or Vaseline and reattach the terminals – start with positive.

3 Tips for PreventingBattery Corrosion

Going forward, there are few simple things you can do to prevent alkaline battery leaks:

  • First, don’t use expired batteries.
  • Second, don’t mix old and new batteries; when replacing one battery in a bay, go ahead and replace them all. Even mixing battery brands commonly causes problems and should be avoided if at all possible.
  • Finally, know that batteries are highly sensitive to heat and must be stored at or below room temperature.