When a lithium ion battery fails, things can go south very quickly. If you open up your phone to find a battery swollen to twice its size, proper care and handling is critical for both your safety and the safety of others.

What’s a Swollen Battery?

The vast majority of modern portable electronics, including laptops, smartphones, tablets, ebook readers, and fitness trackers are all powered by lithium-ion batteries. As far as compact batteries go, they’re pretty great. They have high energy density, low self-discharge, and a very tiny memory effect: all features that make them perfect for inclusion is everything from MacBooks to Kindles.

Unfortunately there’s no such thing as a free lunch, so to speak, and all that high-density energy goodness comes with a trade off. Compared to its predecessors, the lithium-ion battery is less stable. Lithium is more reactive than previously used compounds, the batteries have very small partitions between the cells and the outer covering, and the entire battery is pressurized.

When lithium-ion batteries are over heated, over charged, or simply failing due to old age, it’s possible for the inner cells of the battery to outgas a flammable electrolyte mixture. This is where the swollen battery effect comes from: the batteries are designed to contain, as a fail safe measure, that out gassing so that it doesn’t cause a catastrophic fire.

If the swelling is minor, you might simply notice that something seems a little off with your device: the back of your smartphone might seem slightly distorted, the frame of your Kindle might have an unusual gap, or maybe the trackpad on your laptop seems sort of stiff. We were recently preparing a pile of old smartphones for recycling, for example, and when we removed the back of the phones to double check for microSD cards, one of the batteries was swollen and the back of the case popped off like it was spring loaded. We happened to have a spare identical battery on hand for comparison.

Although it’s not extremely dramatic to look at, the little smartphone battery has clearly failed and the center of the battery is swollen to roughly 150-200% the size of the healthy battery and the case could no longer be safely closed.

On the other end of the spectrum you’ll find extreme examples where the expansion of the battery outright rips the surrounding electronics open. In the photo below, courtesy of Reddit user iNemzis and /r/TechSupportGore, you can see how the expansion of a MacBook battery was so powerful it actually ripped the trackpad right out of the frame of the laptop.

Now, before you panic, we do want to emphasize that for the most part lithium-ion batteries are really safe. There are multiple safety measures built into them (like over-charging protection circuits, temperature gauges, and so on) and even though the batteries in both of the above photos have clearly failed, they did not burst into flames. The safety measures worked and no one was hurt.

Let’s take a look at how to safely remove and dispose of a swollen battery and, in turn, what you can do to prevent swollen batteries before they start.

How to Remove and Dispose of a Swollen Battery

Although lithium-ion batteries generally don’t fail catastrophically and hurt anyone, you still need to treat them with the kind of respect could-explode-and-burn-you objects deserve.

Do Not Charge or Use the Device

Once you notice the battery is swollen or compromised in any way, you should immediately stop using the device. Turn the power off, and above all else, do not charge the device. Once the battery has reached such a point of failure that the battery is swollen, you must assume that all safety mechanisms in the battery are offline. Charging a swollen battery is literally asking for it to turn into an exploding ball of noxious flammable gas right in your living room.

Remove the Battery

When it comes to removing the battery, there is one very important rule: don’t further compound the problem by compressing, distressing, or compromising the outer casing of the battery. If you puncture the swollen battery, you’re in for a bad time as the compounds inside will react with the oxygen and moisture in the air.

If your device is user-serviceable and you can easily open the case or a service panel to remove the battery, then doing so is in your best interest: it will prevent the expanding battery from (further) damaging your device and it will prevent any sharp edges inside the battery compartment from piercing the protective layer around the battery.

Once you have removed the battery, you should do two things immediately. First, insulate the contacts of the battery (if exposed) with a piece of electrical tape. The last thing you want is for something to short the terminals out. Second, store the battery in a dry cool place away from flammable things until you can safely transport it to a disposal facility.

If your device is not user-serviceable, and you can’t easily remove the battery, then you should take the device to a service location, specialty battery shop, or an authorized battery recycler (see below). There you should find someone with the tools/skills to help open your device and remove the damaged battery.

The same general rules apply even when you can’t remove the battery yourself: take the whole device and store it in a dry cool place to minimize any further degradation of the battery cells and keep it away from anything flammable.

Dispose of the Battery at an Authorized Recycling Center

Whether they are damaged or not, lithium-ion batteries should never, ever, be thrown away. Not only is the battery the kind of environmental hazard you don’t want sitting in a landfill, but even a brand new lithium-ion battery is a fire hazard if it is punctured or shorted out in the trash can or garbage truck. The risk of starting a fire in your own home and injuring yourself or starting a fire in a sanitation truck and injuring the workers is simply too high.

Lithium-ion batteries–new, used, or damaged–should only be disposed of via authorized recycling centers. To locate recycling centers near you, your best bet is to use a recycling location index like Call2Recycle or to call your local city/county hazardous material disposal center.

When disposing of a swollen lithium-ion battery, we strongly encourage you to call ahead and ask if the facility is equipped to accept a damaged battery and to check what the protocol is for bringing the battery in. Do not simply toss a swollen battery into a general battery recycling bin at your local big-box electronics store.

How to Prevent Swollen Batteries

RELATED: Debunking Battery Life Myths for Mobile Phones, Tablets, and Laptops

You may have read the preceding sections with interest, but thought “Well I don’t have a swollen battery right now but I definitely don’t want one in the future”. In your case, then, the goal is to keep your batteries happy and avoid premature battery failure.

Fortunately for you, you can accomplish this by following the same rules for extending the general life and happiness of your lithium-ion batteries.

Keep Your Batteries Cool

Lithium-ion batteries hate heat. While it’s impossible to keep them perfectly cool all the time, you should make it a habit to avoid leaving your electronics where they’ll get roasted. Don’t leave your laptop in your car on a scorching hot day, don’t leave your phone charging on the kitchen counter where the afternoon sun bakes it, and otherwise do your best to keep the battery cool.

When you aren’t using your devices or spare lithium-ion, store them in a cool and dry area of your home.

Use a Quality Charger

Overcharging is a serious threat to the health of your batteries. If the official battery charger for your laptop costs $65 and the generic knock-off charger you found on eBay costs $9, you might want to reconsider. Quality parts and safety certifications cost money and what you save on the charger you could lose on a damaged laptop and battery (at best) or in a fire (at worst).

Replace Old Batteries

If you notice that your battery is no longer holding a solid charge, then you should consider replacing it. If you used to get 5 hours off your laptop battery and now you get 30 minutes, that’s a good sign that the components of the battery are degrading. Not only will replacing the battery give you that nice multi-hour battery life back but it will ensure that you’re not using a battery on the verge of failure.

Don’t Leave It Plugged In

You don’t need to constantly charge your battery. It isn’t good for the battery, it introduces additional heat, and your batteries are happiest when they aren’t too hot and aren’t too full.

This doesn’t mean that you can’t leave your laptop plugged in while in the midst of a marathon work session, but you don’t need to leave it plugged in all day, every day.

By following some simple rules to keep your batteries healthy and then properly disposing of them when they fail, you’ll avoid injury to yourself and your electronics.

Profile Photo for Jason Fitzpatrick Jason Fitzpatrick
Jason Fitzpatrick is the Senior Smart Home Editor at How-To Geek. He has over a decade of experience in publishing and has authored thousands of articles at How-To Geek, Review Geek, LifeSavvy, and Lifehacker. Jason served as Lifehacker's Weekend Editor before he joined How-To Geek.
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