Under normal circumstances, a battery simply runs out and needs a replacement, but there are occasions when we are betrayed by this technology, and its consequences are… flaming, so to speak. There is little to do with a device that has caught fire; however, the middle ground is a battery that leaks electrolyte, and it requires our immediate intervention. Fortunately, battery leaks are not that difficult to clean, and with a bit of luck, it is possible to detect them before they ruin the device.
From those explosive problems we've seen in the past, I think we are now more attentive to how our batteries behave, especially those with lithium-ion technology. The explosive character of these batteries gives them a much more media-friendly profile, but the truth is that their alternatives are not perfect either. The corrosion of alkaline batteries is relentless, and acid-based units can eat up anything in their path if we don't keep a close eye on them. The good news is that in most cases we can clean the spills relatively safely. It all starts with correctly identifying the battery and having access to basic, very low-cost materials.
How to Clean Alkaline Batteries
Alkaline batteries are often considered the most stable on the market, but it's not uncommon to find a remote control or toy ruined by batteries we forgot to remove. Every cleaning process seeks the neutralization of fluids, so corrosion in alkaline batteries (caused by potassium hydroxide leakage) requires an acid.
For cleaning alkaline batteries, the ideal candidates are vinegar and lemon juice. For minor incidents, a swab dipped in vinegar should be more than enough to neutralize the electrolyte, clean the battery compartment, and the contacts.
In contrast, if the corrosion has caused considerable damage to the contacts, we'll need a deeper restoration (combining vinegar with an abrasive material like sandpaper), or outright replacement of the device. Contrary to what other guides say, nickel-cadmium and nickel-metal hydride batteries have an alkaline electrolyte, and they are also cleaned with vinegar. The difference is that they demand more careful handling. Cadmium is well known for its toxicity, and it is recommended to use gloves to avoid skin contact.
How to Clean Lead-Acid Batteries
On the other side are lead-acid batteries, similar to those found in any car. Emergency lights and uninterruptible power supplies (UPS) depend on this chemistry, and although in general their batteries are sealed, the possibility of a spill never completely disappears.
The electrolyte of these batteries is dominated by sulfuric acid, and when it comes to neutralizing it, our main ally is baking soda. Personally, I have had great success with 10-20% solutions, and the idea is to repeat the process until we see no more reactions. Patience; this is not a race.
What About Lithium Batteries?
Finally, we come to lithium. I must confess that I have never observed a lithium-ion battery with a leak, and the images we can appreciate here show them swollen from gas accumulation. In the first case, the suggestion for cleaning the electrolyte (based on lithium salts and some organic solvent) is a piece of cotton or a cloth of that material, barely damp with distilled water.
Now, if the battery is swollen, we need to be very careful when removing it. Under no circumstances should they be punctured, no matter how great the temptation. The only destination for a battery in that condition is the recycling center, and even there they are dangerous. Do not throw the battery in a trash can, and warn those in charge that the battery has gas accumulated. Why? Simple: the battery has become an explosion and fire risk.
In Summary
Almost all damage caused by faulty batteries can be repaired with a good cleaning and a proper replacement, and by far, lithium-ion batteries are the ones that require the most attention to detail. To finish, most non-rechargeable alkaline batteries go in the regular trash (unless the battery itself indicates otherwise), but all others need to be disposed of specially. Good luck!
