Can You Fix an Electronic Device After the Battery Corroded?

Batteries are amazing things when you stop to think about it. They're lightweight, relatively inexpensive, and an absolute necessity for most of the electronics that make up our lives. Unfortunately, all good things come to an end, and with batteries that end can get pretty messy. Almost everybody's had the experience of finding a device filled with battery corrosion after a few months forgotten in a drawer or at the bottom of a toy box. A battery leak in an electronic device is sometimes the kiss of death, but often the device can be cleaned or repaired.

The white stuff you find on batteries happens when they sit for too long and get old, or sometimes when you've accidentally mixed different types of batteries. In the average battery compartment, you're going to see a form of potassium, because that's what generates the current in mainstream alkaline batteries. As the battery's name tells you, this is an alkaline chemical. Cleaning it up is the first step in figuring out how badly your device is damaged.

The first step is to get your old batteries out of there. It's best to wear disposable gloves while you're doing this because the chemicals are caustic. You should also protect your eyes – you don't want this stuff in your eyes – so if you don't have safety glasses, even putting on a pair of reading glasses or sunglasses helps. Gently pry the batteries out without applying enough force to break them, and then bag each one separately for disposal. If you're not sure where to take them, check the website of your local municipality or waste management company.

Now, set out a few layers of newspaper or a disposable plastic tablecloth under the device, to protect your tabletop or counter. Rub away as much loose corrosion as you can with a dry cloth, and then pour out a splash of white vinegar into a small bowl and set it within easy reach. Take a cotton swab or a corner of your cleaning cloth and barely moisten it with the vinegar. Swab it gently over all the visible battery corrosion. You'll see a bit of fizz happening, which is the acidic vinegar reacting with the alkaline battery corrosion. After it dies away, wipe the corrosion again with the dry cloth. Keep going until you've removed as much as you can. You might have to use a toothbrush or a toothpick to pick away at some of the crusted-on parts. For the last layer of corrosion, you can use a pencil eraser to buff it away. Be careful not to use so much vinegar that it leaks into your device. Dribbling acid onto a delicate circuit board isn't going to do you any favors.

After you've cleaned away all the visible corrosion, let the device dry for several hours or overnight. Then you can put in a new set of batteries and see if your device works. If it does, all is well. Chalk it up to experience, and hopefully, you'll remember to take the batteries out the next time you put something into storage. If it doesn't work, then you need to dig a little deeper. You can often repair battery leak damage, but it depends on your level of skill and motivation. To put that another way, it depends if the cost of buying a replacement outweighs the time and effort of the repair.

If the terminals in the battery compartment are badly corroded, they may not be able to conduct electricity anymore. If you can, remove the circuit board that holds the battery holder. You may see some corrosion on the back, which you can remove in the same way you cleaned the battery compartment. If you have a multimeter, test the terminals by setting the meter to continuity and touching one lead to the battery terminal and the other to where the terminal is soldered onto the board. If there's no circuit, remove the old terminals and solder in a new set. You can find those online or at electronics repair shops. You should also look to see if any of the solder joints on the board appear to be corroded. If so, re-solder them. If none of these steps work, it's sometimes possible to order a replacement circuit board for your device. You'll have to make your own decision about the cost and level of effort you're willing to put into the repair.