Sometimes you don’t get around to using an old flashlight that you have. Maybe it gets mislaid for a while or maybe you just don’t need it. Then you go to use it and it doesn’t produce any light. If it has a battery compartment, when you open it, there is white fuzzy stuff. Since I was expecting this from the moment the flashlight didn’t work, I usually open it over a rag or a strong paper towel. I don’t open it over a food-related surface.
You’d rather not get that white fuzz on your hands, so many people would grab a pair of rubber or plastic gloves. Whatever you do, don’t rub your eyes, as battery residue can cause chemical burns.
If you caught the corrosion before it got too bad, the battery may just come out if you tap on it, and you can dispose of it carefully. Otherwise, removing the light section at the end of the flashlight may let you push through. Corrosion does take up some space.
Before you get rid of that rag or paper towel, if there is still white stuff in the flashlight, get a toothpick and wrap something (like a small piece of toilet paper) around it, or use a q-tip. For a larger battery, an old toothbrush is a good tool. Slightly moisten whatever you are using and then wipe out the flashlight. Sometimes people moisten with white vinegar. People also use moistened baking soda at times.
Then let the flashlight air-dry.
When you put new batteries in, with luck you’ll be back in business.
No luck? You can repeat the process, but at a certain point if it’s a cheap flashlight, just get rid of it in a plastic bag in the trash.
Be sure to clean up the area and wash your hands thoroughly.
To Avoid Corrosion in the First Place
If you don’t expect to use a particular flashlight for some time, take its batteries out and put them in a bag with a label or note saying which flashlight they are from. This could be the case for a light you only use when you go camping, for example, or one you keep in your car.
Using rechargeable batteries helps with this problem, but rechargeables can in many cases also corrode.
Disposing of the Batteries
If there is a place in your town or city where you can recycle batteries, then bag up the corroded one or ones apart from any that are just used up. You can use a bag, one that won’t spill any of the corrosion out.