Nancy asked: A battery corroded in the bottom of a flashlight. How can I remove it without ruining the flashlight? This is a small, plastic flashlight that uses 2 AA batteries. I left one batter in the bottom for two year, and now it is corroded. New batteries do not work in this flashlight. How can I clean out the corrosion without damaging the working mechanism of the flashlight? Thank you.
Corroded batteries can be a real nuisance to remove and clean up. But when it comes to saving the flashlight, it is often worth the effort. The first step is to remove the battery while keeping it as intact as possible. Then, it’s time to tackle the mess left behind. Here’ s what to do:
You Will Need:
- Rubber gloves
- Bottle brush
- White vinegar
- Dowel rod (small enough to fit in the flashlight, but as large as the diameter of the battery)
- Drill (optional)
- Piece of wood or hard surface
Steps to Clean Out the Battery and Corrosion:
- The first step is to put on gloves and eye protection. Battery corrosion is very caustic and touching it could give you chemical burns.
- Remove the corroded battery. If both ends of the flashlight are removable, this will be quite easy. In this case, just place the flashlight on a piece of wood or other hard surface.
- Place a dowel rod in the flashlight and on top of the corroded battery.
- Tap the end of the dowel rod with a hammer to knock the battery loose.
- Remove the battery and dispose of it properly.
- If both ends of the flashlight cannot be removed, it will be slightly more difficult to remove the old battery, but it can be done. One method is to use a drill.
- Use a drill with a long bit and screw it into the end of the battery.
- Once the bit is secure in the battery, pull it out. It may take some maneuvering, but the battery should come out with it.
- Next, you will need to remove the corrosion from the interior of the flashlight.
- First, inspect your flashlight to determine where the electrical parts are. Usually they are located right around the bulb, not near the battery compartment.
- If the electrical parts are located near the bulb (separate from the battery compartment), you can use a mild acid (vinegar) to loosen the corrosion and scrub it away. This works on both alkaline and acidic batteries. (Skip to step 16 if the electrical parts are not separate from the battery compartment.)
- Pour some white vinegar into the battery compartment. You only need a little; just enough to wet the corrosion. Don’t be surprised if it starts fizzing; that means you had alkaline batteries.
- Use the bottle brush to scrub the inside thoroughly. If you don’t have a bottle brush, you can use a cleaning cloth wrapped around a piece of wire, such as an unfolded wire hanger if needed. Do not put your hand into the flashlight; you may get chemical burns from the corrosion.
- If necessary, allow the vinegar to soak in the flashlight for a few minutes, but no more than five minutes total.
- Rinse thoroughly with clean water.
- Dry it as much as possible with a soft towel and allow it to air-dry completely before use.
- If the electrical parts on your flashlight are not separate from the battery compartment, do not pour vinegar into the flashlight as it might seep into the electrical area. Instead, wet a cloth with the vinegar and wring it out so that it is only damp, not dripping.
- Wrap the damp cloth around something sturdy like an unfolded wire hanger or a stick.
- Put on rubber gloves.
- Use the cloth to clean out the corrosion.
- Rotate the cloth to a clean area as you remove the corrosion.
- Continue wiping out the corrosion until it is gone.
- Use another cloth that is damp with plain water to wipe out the inside to remove any remaining residue.
- Allow the flashlight to air dry fully before putting in new batteries.
Additional Tips and Ideas
- Battery acid should not come in contact with the skin. Protect your skin with rubber gloves while cleaning corroded batteries.
- Some have found Coca Cola effective for removing corroded batteries. Simply soak the battery in the cola then tap lightly until the battery falls out.
- If the battery is not too badly corroded, it may be possible to remove it with vigorous shaking.
- Baking soda has also been found effective for removing corroded batteries. Simply pour some soda into the flashlight, then shake it slightly to distribute the powder. Next, tap the sides lightly to dislodge the battery and remove it.
- The primary goal is to remove the corrosion, not to neutralize it. If you have alkaline batteries, using vinegar will neutralize the corrosion (which is just an added bonus) and the chemical reaction will help to jar the corrosion loose so it can be removed. For acid corrosion, the vinegar will dissolve it so that it can be removed, which may be a more effective method. If you want to neutralize the acid corrosion, you would have to use an alkaline material, such as baking soda dissolved in water.