How to Get Corroded Batteries Out of a Flashlight?

Last Updated on May, 2024

Corrosion is the CANCER of flashlights! When battery corrosion happens, you have to be careful and quick to address the matter if you want to SAVE your flashlight. 

This article will tell you exactly how to get corroded batteries out of a flashlight. Everything you will need to do will be listed for you. Hence, keep reading this word to word to figure out how to get corroded batteries out of a flashlight. 

Quick Summary

Corrosion can damage flashlights and cause them to malfunction.

It is possible to remove corroded batteries from a flashlight and clean the battery compartment to remove corrosion.

A combination of vinegar and baking soda can be used to dissolve battery corrosion and loosen stuck batteries. Gloves and eye protection should be worn when dealing with battery acid.

Can You Remove Corroded Batteries From Flashlight?

Corroded Battery inside a flashlight

Yes, you can remove corroded batteries from a flashlight. Stuck batteries will need more attention, and swollen batteries can be harder to remove. Though you can remove corroded batteries from a flashlight, some batteries will be harder to remove than others. 

That being the case, a normal type battery with a bit of corrosion due to a broken battery seal is not something that should be too difficult to work with. 

Following the steps and advice provided in this article, you will master removing corroded batteries. 

A corroded battery could have battery acid leakage, and battery corrosion can ruin the whole battery compartment.

Hence, it is important that you not only remove the corroded battery from the flashlight but clean the battery compartment to remove the corrosion, which otherwise may cause your flashlight to malfunction. 

When dealing with alkaline batteries, you want to carefully remove the battery as per these instructions and clean the alkaline battery leakage properly.

How to Remove a Stuck Corroded Battery?

To remove lodged corrosion, you will need a few things. For this example, let us assume that you are dealing with lodged corroded alkaline batteries. 

What You Will Need?

Baking soda on the table
white vinegar on the table
Tin foil
Rubber gloves on the table
a human holding a eye protection glass
  • Baking soda solution
  • Vinegar (white vinegar)
  • Tin foil
  • Rubber gloves and eye protection

Step-by-Step Process

For alkaline batteries that may have gotten stuck due to corrosion, you don’t want to start jamming it with a fork, hoping it will fall out. You want to use a carefully calculated scientific reaction to remove the stuck battery. 

First, you take the baking soda and combine it with vinegar (a tablespoon is preferable). The baking soda and vinegar react together to formulate the dissolving of rust and corrosion.

It is this property of baking soda in combination with vinegar that provides the right chemical reaction to remove the corroded battery from the battery holder. 

The battery corrosion may have caused battery acid leakage in the battery compartment. Hence, before even opening up the battery compartment, you have to get your hands in some rubber gloves.

This is for basic protection, as battery acid can damage the skin. So wear gloves and put on some eye protection! (A battery leak can be dangerous to the skin.)

You can now remove the battery holder’s cap and reveal the corroded battery stuck in place. Flashlights that offer limited access to the battery of the flashlight make it more difficult to remove a stuck battery. If the battery is inbuilt, you may need technical expertise to expose the battery.

You then want to take the baking soda and vinegar combination and pour it into the battery holder. The combination of vinegar and baking soda will not work to react with the corrosion and dissolve it. 

However, you aren’t done yet. Take the tin foil and cover the open end. The tin foil is also a part of the requirements for the reaction. You need tin foil, so don’t forget about it. 

With the tin foil held against the open end of the battery holder, shake the combination of vinegar and baking soda by shaking the flashlight (gently shake). This will allow the vinegar and baking soda to seep into hard-to-reach spots inside the battery holder.

The batteries will be loosened by the reacting chemicals, which work to dissolve battery corrosion. With the battery corrosion partially dissolved and the battery loosened, you can now remove the tin foil and allow the corroded contents of the battery holder to fall out. 

You are now ready to clean the flashlight, air dry it, place new batteries and learn how to prevent battery corrosion. 

Things to Remember

Remember, wearing gloves should not be sidestepped. These reacting chemicals and the resulting byproducts are dangerous when in contact with skin; hence when removing corrosion, you should use gloves and, if possible, also use some form of eye protection. 

If your battery is really jammed into place, you can try to drill it first with a cork screw or a coarse lag screw threaded into the battery.

Make a small pilot hole (drill), which should be enough to do the trick. (Don’t pull.)

a human holding a Stuck Corroded Battery flashlight

Batteries corrode when they are left unused for a long duration of time. If you aren’t using your flashlight yet, don’t place new batteries in there again and let it corrode AGAIN… 

When dealing with an alkaline battery, one of the byproducts of the reaction could be hydrogen gas. The gas buildup could cause a pressure buildup, leading to the rupture of the battery seal, which would result in potassium hydroxide leaking out.

Hence to prevent damage to the skin, ensure you are wearing gloves. Gloves and eye protection are both very important. 

After removing and cleaning the flashlight, you want to check if the flashlight is working. If your flashlight DOESN’T work, first check the light bulb (the bulb), which may need changing.

Before placing the new set of batteries, you want to air dry completely to ensure there is no chemical left on the flashlight. 

But before allowing it to air dry, give your flashlight a good clean.

How to Clean Corroded Batteries of Flashlight?

What you need is lemon juice. Lemon juice has the right acidity to remove and clean corrosion. Hence, get your hands on some lemon juice and clean the inside of the battery holder for spots with corrosion. 

You have to clean the battery case too, which too could have corrosion on it. Gently shake the flashlight with lemon juice in the battery compartment to remove corrosion buildup inside it. 

You can cover the open end with your hand when shaking to clean the flashlight or replace the cap, whichever you prefer. 

The old battery would have left scars on your flashlight, and if the corrosion is heavy, you will want to use a wire brush to gently scrape the corrosion off. 

A vinegar solution can also be used instead of lemon juice to remove corrosion. 

Once the corrosion has been removed, use a soft cloth to dry the inside and let the flashlight air dry. You want it to properly dry on the inside, not just the flashlight casing. 

Clean the removable bottom and safely remove all the removable parts of the battery holder and clean the flashlight properly. You can use a small brush if you prefer. 

The acid in vinegar and lemon juice is what will react with the corrosion to dissolve it. Before using clean water, you want to use an acid like vinegar to remove the corrosion.

Remember to wear gloves when cleaning too; you don’t want to get corroded rust on your skin.

Why Do Batteries Leak and Corrode?

Batteries leak and corrode when they have been left unused for a long duration of time. Hence frequent battery changes could prevent battery corrosion. 

The chemical change that occurs in many flashlights left UNUSED will lead to natural corrosion buildup over time. 

The pressure buildup in the battery could have led to rupture, leading to a leak inside, which would have left behind a mess inside the flashlight. This mess inside is what will lead to corrosion. 

When dealing with corrosion, you want to use a neutralizing agent, which is the safest and easiest way to deal with battery leaks and corrosion.

Battery leaks and corrosion are a natural phenomena. It is what happens to batteries when they are left UNUSED, inside the device (flashlights) for too long.

Related article: Are Flashlight Batteries Recyclable?

What Do Corroded Batteries Do to Flashlights?

Corroded Batteries on the table

Corroded batteries could seriously hamper the performance of a flashlight. Your flashlight may never be able to recover from a bad amount of corrosion left unattended for too long. 

Corroded batteries break flashlights. The longer you keep corrosion unattended, the more likely that it will permanently damage the flashlight. 

The corrosion that is built up inside a flashlight could lead to the damaging of the battery compartments of the flashlight. Corrosion in the battery compartment may mean that even if you replace the batteries, the corrosion may cause your flashlight to not work. 

Hence it is important that you remove corroded batteries carefully and quickly and not allow the corrosion to take more of a toll on your flashlight.

If your flashlight stopped working, here’s what to do.

How to Get Dried Battery Acid Out of a Flashlight?

The best way to deal with dried battery acid is by relying on a neutralizing agent such as vinegar or lemon juice. 

Dried acid should be gently cleaned with vinegar. Even if the acid is dried and attached into place, rinsing and gently swiping with vinegar or lemon juice should do the trick of cleaning that dried battery acid right out. 

How to Store a Flashlight to Avoid Battery Corrosion?

flashlights on the chair

When dealing with corrosion, the one thing to keep in mind is the fact that corrosion happens when the battery is left UNUSED for a long duration of time. 

Hence, if you are not using your flashlight, it is best to remove the battery until you need to use the battery again. Keeping the battery removed from the flashlight completely saves you the trouble of having to deal with corrosion. 

Secondly, you don’t want to over-drain your batteries and overuse them. This could lead to battery leakage, which will, in turn, lead to corrosion. Hence, frequently changing batteries when necessary is a good idea to prevent corrosion from building up. 

Dos and Don’ts of Flashlight Care


  • Do take care of your flashlight. When not using the flashlight, take the batteries out. 
  • Do safely remove the compartments of your flashlight for inspection of corrosion.
  • Do periodically clean your flashlight for corrosion. The more corrosion builds up, the worse it is for your flashlight’s health. 
  • Do replace batteries when necessary to prevent battery leakage due to overuse. 


  • Don’t leave batteries in your flashlight left unused. 
  • Don’t use water and a brush to clean the corrosion.
  • Don’t shake or scrub too hard when trying to remove and clean corrosion.

How to Prevent Battery Corrosion in Flashlights?

flashlights and Batteries

The best way to prevent battery corrosion in a flashlight is by ensuring that you don’t leave your flashlight batteries in the flashlight battery compartment UNUSED for a long duration of time. 

The longer your flashlight goes UNUSED, the greater the chances of corrosion. Hence, when not using your flashlight, it is highly recommended that you remove the batteries and store them separately to prevent battery leakage and corrosion from damaging your flashlight. 

This is the best way to prevent corrosion in flashlights. Other than this, if the flashlight is being extensively used, you want to periodically check the batteries for leakage and corrosion and change batteries whenever it becomes necessary. 

Final Thoughts

Corrosion can be a horrible nightmare if you love your flashlight. Maybe you forgot to take the batteries out and store them separately or you didn’t know. Regardless, now you know how to deal with corrosion and how to better care for your flashlight. 

Corrosion left unattended can be very damaging to a flashlight. The sooner you realize there is corrosion buildup in the battery compartment; you want to deal with it. The more promptly and safely you get this corrosion out, the more the chances of your flashlight surviving.

Remember, corrosion is the cancer of flashlights and even a small amount of corrosion may be detrimental to the performance of your flashlight. 

Follow the steps provided in the article to not only remove the lodged corroded batteries but also CLEAN the flashlight prior to reuse. 


Yes, battery corrosion can ruin a flashlight if it is not cleaned and attended to in a timely manner. It is important to clean corrosion before it builds up in order to avoid damage to the flashlight.

Yes, vinegar helps dissolve battery corrosion when used in combination with baking soda.

Yes, corroded batteries can be removed from a flashlight by using vinegar, baking soda, and tin foil.

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Dillon Morrison
I have been involved in the flashlight community since 2007. My brother has a flashlight shop from where I have tested and reviewed more than 600+ different types of flashlights. You can find more about me here.

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