Learning, Battery,

How to Get Corroded Batteries Out of a Flashlight

If you leave a battery inside a flashlight for a long time, it will probably experience corrosion, and you might find it difficult to remove the corroded battery.

If the battery is stuck, you must find a way to clear the corrosion and dislodge the battery. Fortunately, you can use some readily available substances.

Quick Summary: Baking soda is very effective for removing corroded batteries. Apply some onto the affected area, shake the flashlight slightly to ensure even distribution of the powder, and tap its sides to help dislodge the battery. The battery should now be loose and easily removable. You can apply vinegar and hammer or drill if the batteries don’t come out easily.

I’ll show you how to get a corroded battery out of a flashlight in more detail below.

a corroded battery on the grass

Safety First

Wear rubber gloves to protect your skin.

They will help to prevent acidic corrosion from coming into contact with the skin: the more the corrosion, the more the importance of protecting yourself.

Also, whichever of the methods below you will use, apply the solution only to the corroded spots in the battery compartment. Try not to let it get inside the circuitry. If you use a cloth or tissue, it should only be damp, not dripping. After removing the battery and cleaning the compartment, allow it to air dry thoroughly before using it.


Things You Can Use to Help Remove Corroded Batteries

You will need to loosen the corrosion to get a corroded battery out of a flashlight.

A few things you can use include baking soda and vinegar. They will not only help to get the corroded battery out but can also help remove the corrosion.

cleaning the interior of flashlight using brush and baking soda
Video | Dandlinc

Baking Soda

Baking soda is an alkaline powder, making it ideal for removing corrosion, which is acidic, or neutralizing it.

Using Vinegar

You can also use vinegar to remove the corrosion but apply it carefully as it’s a liquid.

It will neutralize and loosen the corrosion, helping to dislodge the battery.

Coke or Pepsi

Coke and Pepsi are also effective for removing a corroded battery if you’re not worried about it getting into the rest of the flashlight.

Add some Coke or Pepsi to the flashlight and lightly tap or shake it.


Getting a Corroded Battery Out of a Flashlight

If you’re finding it difficult to get the corroded battery out of a flashlight, here’s a more thorough method you can follow.

Step 1: Remove the Outer Cover

Remove the flashlight’s outer cover to get clear access to the corroded terminal and battery.

Step 2: Pour in Baking Soda or Vinegar

Apply the alkaline substance directly onto the corroded areas in the battery compartment.

You can use baking soda or vinegar alone or make a solution using the two. About a tablespoon of each should be more than enough. This will neutralize and loosen the acidic corrosion, eventually freeing the battery.

Step 3: Cover with Tin Foil

The applied solution might also become acidic after mixing with the corrosion.

You might also need to shake the flashlight. So, to be safe, cover the open part of the flashlight with tin foil.

Step 4: Tap and Shake

Gently tap and shake the battery to help dislodge the battery.

The action will also help disperse the alkaline substance to ensure it gets into the right spots. Be careful, as some alkaline substances mixed with the corrosion may still leak despite covering it with tin foil.

Step 5: Open the Cover

After gently tapping and shaking for about a minute, remove the tin foil and let the mixture drain away.

You may find that the battery has become loose. If not, pour in a bit more of the alkaline substance, ensuring it covers all of the corrosion, especially on the parts holding the battery in place. Then, tap and shake for a little longer.

Step 6: Leave Flashlight to Dry

Once you remove the battery, use a soft cloth to clean the entire compartment.

You can also use a small toothbrush to help clear the areas from the corrosion particles. Once clean, leave the flashlight to dry.

If you’re lucky and the alkaline substance did not get further inside the flashlight circuitry, it should still work with the corrosion removed from the terminals and a fresh set of batteries.


A Sure Way to Get a Corroded Battery Out of a Flashlight

If the corroded batteries have been inside the flashlight for too long, and the batteries refuse to come out easily despite applying the above methods, here’s a sure way to get them out.

Requirements

  • For safety: rubber gloves, goggles
  • Alkaline solution: white vinegar
  • Tools: bottle brush or toothbrush, dowel rod, drill, hammer
  • For cleaning: water, tissue, towel
  • You should work on a hard flat surface.

Step 1: Wear Safety Equipment

Wear eye protection and a pair of gloves for protection.

Battery corrosion is highly caustic and can burn the skin.

Step 2: Gather Everything Together

Gather all the items you need for this task on a hard flat surface. A tabletop will do.

Step 3: Set the Dowel Rod

Set the dowel rod on top of the flashlight, as shown in the picture below.

Don’t put your fingers inside the flashlight; you may get chemical burns. Allow the applied solution some time to dissolve and remove all the corrosion. About 2 or 3 minutes should be enough.

Then, rinse the compartment and use tissue to clean it thoroughly. Allow it to air dry before using the flashlight again.

Step 4: Tap the Dowel Rod

Lightly tap the dowel rod with a hammer to exert downward pressure on the battery inside.

This may help to dislodge the battery, and you will not need to proceed further except for cleaning the flashlight, i.e., skip Step 5.

Step 5: Use a Drill

This step is only necessary if the dowel rod fails to dislodge the battery.

It will damage the battery by creating a hole in it, but if you’re not bothered by that, it’s a sure way to get the corroded battery out.

Use a power drill with a long drill bit. Drill straight into the battery’s exposed end until the drill bit holds the battery securely.

Then, pull the drill, and the battery should come out this time. You might need to wiggle the drill a bit and hold the other end of the flashlight, but as long as the bit is firmly inside the battery, it should come out while pulling.

using a drill to hole the interior of the flashlight
Video | Mr. Kongable

Step 6: Remove the Corrosion

If you want to use the flashlight again, you must also remove the corrosion inside it.

Use the method described earlier to remove it. Use baking soda or vinegar solution and a small brush to scrub the corrosion.

Don’t put your fingers inside the flashlight; you may get chemical burns. Allow the applied solution some time to dissolve and remove all the corrosion. About 2 or 3 minutes should be enough.

Then, rinse the compartment and use tissue to clean it thoroughly. Allow it to air dry before using the flashlight again.




References

Video References

Dandlinc

Mr. Kongable

World According to Ted

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About Alex Robertson

AvatarCertifications: B.M.E.
Education: University Of Denver - Mechanical Engineering
Lives In: Denver Colorado

Hi, I’m Alex! I’m a co-founder, content strategist, and writer and a close friend of our co-owner, Sam Orlovsky. I received my Bachelor of Mechanical Engineering (B.M.E.) degree from Denver, where we studied together. My passion for technical and creative writing has led me to help Sam with this project.

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