Here’s why your gadget batteries start to swell over time

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Of the many laptops that have landed on his desk in the past two months, IT specialist Gareth Belton says he’s seen seven or eight with swollen batteries.

The 22-year-old, who works for a small farming business in central Maine, said none of the batteries were that old – maybe three to five years old by his count.

After discovering another bloated battery that he would eventually store in a yellow, fireproof safe, Belton shared his findings with r/spicypillows, a Reddit community of more than 60,000 members who post images of batteries used in laptops, phones, mp3 players and game consoles that have swelled well beyond their original size.

“I would say it happens in about 10% of the laptops I deal with,” Belton said. “I’ve seen it in phones, but more rarely.”

Reports of battery swelling have become more common as our addiction to rechargeable gadgets deepens, and the results can be alarming to say the least. It’s not uncommon to see batteries soar to the point of splitting the device they were once sealed in. (Imagine the consumer electronic version of a Chestburster from “Alien” and you’re on your way.)

But don’t jump to conclusions: as surprising as this swelling may be, it’s not always a sure sign of danger – it’s just that the battery won’t last as long as it used to.

Here’s what you need to know about why it’s happening, what you can do to minimize the chances of seeing a swollen battery, and what to do if you already have one.

Are swollen batteries dangerous?

They can be, but that’s not a sure thing.

“Swelling is definitely not good, and it’s an indicator of diminished performance,” said David Mitlin, battery researcher and professor at the University of Texas at Austin. “But that doesn’t instantly mean the battery will catch fire.”

Even so, swollen batteries can cause problems. They could, for example, damage other parts of a device as they grow. A smartphone’s fragile screen can crack if an expanding battery puts too much pressure on it. In a laptop, meanwhile, a battery that has started to swell could push his trackpad out of place or otherwise mess up the computer body.

In other cases, a swollen battery could prevent you from using a gadget as intended. Washington Post tech columnist Geoffrey A. Fowler found a Samsung Galaxy Note 8 in his collection with a battery that had expanded to the point that it burst through the glue that holds the back glass plate in place . (We asked Samsung for a comment but did not receive a response.)

If you have found a swollen battery in your home, or a device containing one, there are a few things to keep in mind. First, do your best to stop using the battery or the product it contains. Don’t charge it either.

Some products, such as cordless phones and some cameras, allow their rechargeable batteries to be easily removed. If safe to do so, carefully remove the battery and store it in a fireproof container. If you don’t have one on hand, Belton recommends placing the battery in a bucket of sand. From there you need to contact a local battery recycling facility, who will know the best way to handle it.

But not every gadget in your life has a battery that you can whip out yourself. If you discover a swollen battery in a product like this, contact the manufacturer for advice. However, if you ultimately have to deal with it yourself, a battery installation should be able to help you figure out your next steps.

What causes batteries to swell like this?

In a nutshell, the gases – exactly which depends on the specific materials inside those batteries. But to understand where these gases come from, we need to look at the chemistry that makes a rechargeable lithium-ion battery work.

Long story short, when you charge one of these batteries, the lithium ions flow from one end to the other and move in the opposite direction when the battery is used to power something. These ions move through a sea of ​​goop called the electrolyte, and as you charge and discharge the battery over time, this goop begins to break down and produce gases as a byproduct. Once enough of these gases have built up, your gadget’s batteries may begin to visibly swell.

So if this degradation is a natural part of how these rechargeable batteries work, why don’t they all swell at some point?

The answer, according to Mitlin, is that not all rechargeable batteries are created equal. Companies invest a lot of money in researching and developing additives that go into electrolytes to try to minimize this degradation. And the way a rechargeable battery is designed also plays a role here.

“All lithium-ion batteries will shape-shift in some form,” said Venkat Viswanathan, professor of mechanical engineering at Carnegie Mellon University. “It’s a law of nature.”

According to Viswanathan, some rechargeable batteries have hard metal shells that resist internal pressure buildup and don’t deform much. But others, like the “pouch” batteries found in devices like laptops and smartphones, have more flexible sides and are more likely to bulge as gases build up inside. .

How can I prevent this from happening in the first place?

Well, you can’t always stop that. It’s just something you’ll have to get used to. That said, there are a few things you can do to minimize the risk of running into a bulging battery in the future.

Don’t let your gadgets get too hot

High temperatures can accelerate the rate at which electrolyte sludge breaks down, which could contribute to gas buildup inside a battery. And even if that heat doesn’t cause the battery to swell, Mitlin says, it will definitely impact how well the battery performs on the road.

Luckily, many of your gadgets include features to keep them from running at high temperatures for long periods of time. Your phones, for example, will notify you when they get too hot – once that happens, they’ll start to disable certain features and reduce the brightness of their screens. In the worst case, they will turn off completely until they cool down.

Laptops are generally more heat resistant because they have built-in cooling systems, but with summer fast approaching, you need to make sure you don’t leave any of your devices in a hot car or under the sun for very long. long time.

Keep an eye on battery charge levels

Keeping a battery at a high state of charge is a great way to wear it down more, so do your tech a favor: don’t leave it plugged into a wall outlet all the time. The reverse is also true: For slightly different chemical reasons, this all-important electrolyte sludge also degrades when a battery is completely dead, according to Viswanathan.

That’s right. Keeping your gadgets fully charged and completely dead can contribute to battery swelling over time.

His advice: Once your gadget’s battery reaches 100%, unplug it and use it as you normally would. Then once you hit the 10-20% range, charge it again.

We know that’s easier said than done.

Usually, if your laptop falls out of your hands, the first thing you worry about is whether its screen is still in one piece. But Viswanathan says these types of drops could lead to situations where one part of the battery is more charged than the others. This could lead to battery bloat, as well as other less than pleasant results.

Some devices, like some laptops, are more vulnerable to it than others because of where their batteries are stored. If your laptop has a battery that you can remove yourself, it may be useful to keep it in a protective pouch when in use. Ditto for phones and tablets: a good case should prevent everything, including the battery, from getting too damaged.


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