Corroded batteries can ruin a Maglite and prevent the light from functioning properly. Maglite flashlights are quality tools that are both reliable and bright in normal working conditions. Removing corroded batteries and restoring the light is worth the effort and requires only a few simple steps. With some prying and cleaning, you can have a quality flashlight back in service.
Remove Battery Corrosion
In most cases, alkaline batteries that rupture are the cause behind corrosion and swollen batteries. The process to remove battery corrosion is simple but tedious. Ideally, you remove ruptured or damaged batteries before they corrode, swell and become stuck in the flashlight. Alkaline batteries have some natural off-gas, but exposure to extreme temperature swings increases internal pressure on the batteries, which can lead to rupture. If you store batteries in a car, keep them in the most temperature-stable location available. The same principle applies indoors. Major temperature swings increase the odds of rupturing a battery and lead to the need for mag light repair. There is no Maglite warranty for battery leak because the battery is a separate component from the flashlight.
Removing the Batteries
When batteries leak, corrode and swell, they tend to get stuck in the light. Put on protective gloves to avoid contact with any leaked chemicals. Start by unscrewing the battery cap and pulling the batteries with needle nose pliers. You should be able to grip the first battery and pry it loose by twisting to break the corroded material loose. Be careful not to flex or damage the battery tube itself. It can take a few tries to break through the corrosion. If the batteries remain stuck, use a stiff wire brush to clean away the corrosive materials. Adding electrical grease or white vinegar while scrubbing helps clean and lubricate the area. After cleaning, use the pliers to pull the batteries from the Maglite.
Restoring Internal Components
After the batteries are removed, scrub the spring and the metal contact point with the wire brush and white vinegar. Remove all visible corrosive material from the two metal points of contact. Also, clean the battery tube until it shines and shows no sign of corrosive material. Dry the light completely before attempting to use it again. A thorough cleaning is typically sufficient to get the light working again. Place new batteries in the tub and test the light. If it fails, continue cleaning or consider replacing the light bulb. If the bulb was not previously burnt out, however, it should be working properly. It will often dim before burning out completely.