Help, my laptop battery is bloated! Now that? (2023)

Lithium-ion batteries perform amazingly for their size. They are strong enough toleave our laptops running for hourson a single charge they are at the heart of the latest smartphones and even power high-end electric vehicles like the Tesla family. But Lithium-Ion batteries have their limitations, and with the performance of laptops in recent years, we're dependent on our devices longer than ever before. And this has implications for batteries: they are inServiceAlso more than ever. And that sometimes means showing the limits of technology.

Maybe this has happened to you before: a laptop or phone you've had for years suddenly stops working, or maybe it's just showing signs of internal physical inflammation. The phone's screen starts to bulge, or its seams come apart, or the laptop's keyboard develops an unsightly bulge. This could be due to a large bubble that has gradually or suddenly formed in the battery. But why is this happening and what can be done about it?

We spoke with some engineers and experts from computer manufacturers and related companies to find out what you need to know about swollen batteries and what to do if you have one.

What makes my battery swell?

Bloated batteries are the result of two things: energy density and heat. Bloating is the result of too much current flowing uncontrollably in a battery cell, leading to a buildup of heat and gas. This happens when a battery's materials degrade or are subject to physical stress or damage over time.

A given laptop battery is made up of many different cells and problems can only occur in one or more of them. Laptop batteries are often referred to as four-cell or six-cell, for example, referring to the battery's internal structure. (Some laptops, usually commercial models, offer a choice of battery capacity/number of cells at purchase, but this is less common than in the past.) The fact that laptops rarely come with removable batteries (in the sense that you can replace them without opening the case) exacerbates the problem.

Bloated battery (right) vs. new AC adapter (Photo: Tony Hoffman)

"The reason these batteries swell is because the electrolyte that separates the layers between the shells breaks down, and when it breaks down, it turns to gas," says Arthur Shi, senior technical editor atiFixit.com(opens in a new window). “Now that the electrolyte is gone, things are no longer insulated and start to short out, causing a hot spot further down the line. This can eventually lead to thermal runaway, which means it can even start a fire.”

The most common cause of a swollen battery is overcharging. According to Shi, keeping the battery in a high state of charge can cause it to become stressed and deteriorate more quickly.

"In an application where a system is plugged in 24/7, after a few years the likelihood of the battery becoming full increases," said Phil Jakes, principal engineer and chief technology officer at Lenovo. “The other thing that drives it is heat. Batteries don't like to get hot, and there's a chemical process that happens when a battery gets hotter than 100 degrees."

Another common cause is mechanical damage to the battery. This could be due to an impact on the laptop or damage from moving it around (or mistaking it for other components in the area). Hitting a hard surface and denting the case can cause a bloated condition, as can exposure to excessive temperatures. Additionally, damage to your device's exterior can be transferred to the battery, causing it to overheat and swell.

Signs of a swollen battery

Well, the signs can be subtle or impossible to ignore. As the battery expands, your device may slowly change shape. For example, your laptop's keyboard may bulge out, or you may notice that the device suddenly wobbles when you place it on a flat surface, and the bottom of the case bulges a little when you look at it from the edge. Or it could be something as confusing as certain keyboard keys that are difficult to press.

If your laptop is easy to open (i.e. has simple screws on the bottom of the case) you can remove the bottom cover and in many cases check the battery's physical condition that way. If it looks puffy or round, it probably means it's swollen. Most importantly, be careful when checking the battery for swelling, as the cells are pressurized. Wear eye protection and do not push or force the cells.

That bloated battery really caused the trackpad to pop out of this laptop's keyboard deck. (Photo: Tony Hoffman)

A swollen battery isn't always immediately obvious when it happens or initially. It depends on how much space you need to expand in your laptop case. On thin laptops, this is usually little or nothing. The size of a swollen battery can range from a small bulge to one big enough to turn your laptop into a rocking chair or even remove your trackpad. (Yes we did.)

How do I fix and prevent a swollen battery?

Once a battery starts to swell, it can continue to run less efficiently. Or your laptop keeps working when plugged in, but dies or quickly shuts down once the cable is unplugged. Finally, don't ignore it; Sooner or later the battery stops working properly and once the swelling starts it is irreversible. The only solution is to change the battery.

Of course, according to the experts we spoke to, there are ways to avoid this or prevent it in the first place:

• Don't leave your device plugged in all the time. Batteries are cyclic and must be discharged and recharged to function effectively.

• Store your laptop in a cool, dry environment. Hot, humid weather conditions increase the stress on batteries and can shorten their lifespan over time.

• When purchasing a new battery, buy from reputable manufacturers. It's usually best to buy a replacement from the original laptop manufacturer rather than the cheaper third-party compatible option.

• Replace the battery when it is old or dead and when the laptop allows you to replace it yourself. Manufacturers test their batteries to last up to three or four years, and in a perfect world, batteries wouldn't degrade, but they do. If you see signs of a damaged, swollen, or dead battery (in which case it will only last a short time), replace it now, not later.

Not everything is pessimism. Manufacturers like Dell and Lenovo have been working on smart battery technology in their laptops for years, allowing the battery to track usage throughout the day to avoid overcharging.

Take Dell, for example. “The battery continuously monitors how you are using your system and puts it into different modes,” said Rick C. Thompson, a distinguished engineer and technology strategist at Dell. "If the user lets us control the battery through context-based charging, we don't fully charge it. We charge it from 80% to 90% and only recharge it before the start of the next day."

How can I replace my laptop battery?

Battery accessibility in modern laptops (i.e., the ability to get into the case and change the battery) varies greatly. Most laptops are built differently internally, with subtle variations, and some simply come with batteries that aren't interchangeable because the case is designed not to open. With Apple MacBooks, some Ultrabooks running Windows (especially some Microsoft Surface Laptop models), and some Chromebooks, having batteries that you simply don't have access to change is sometimes an issue. So the first step is to talk to your laptop tech support to see what your options are. If your battery is swelling, now is the time to take action.

To assess the swollen battery situation, do the following:

• Make sure you can access the battery yourself. Contact your laptop manufacturer's support line or your product's online resources to discuss your options through "official" channels. Some popular models have online (unofficial) tutorials that also walk you through the battery replacement process.

• Find out about warranty coverage and whether it is still valid. (If you haven't paid for an extended warranty, after several years, the answer is probably no.) Note that if you're confident enough to change the battery, it could void your warranty, if any. Also, sometimes a laptop battery is covered by a shorter warranty than the main laptop itself.

• Be realistic about what it takes to get the job done. If you want to try to solve the problem yourself, don't use any old tools. You may need a special screwdriver or two (Philips screws are common on laptops) and sites like iFixit sell them.special tool kits(opens in a new window)for Mac and other machines. Depending on the product and manufacturer, a swollen battery can be the kiss of death for some laptops. “The battery may have a UL rating or a rating that determines whether it can be repaired by a service center or customer support engineer,” says Thompson.

• Most importantly, at the first sign that the battery is swelling, back up all important data as soon as possible and stop using the laptop.

What should I do with my swollen battery?

The only thing you can do with your old, bloated battery is throw it away. With Li-Ion batteries, care must be taken to avoid damage to the battery when handling or removing it from the PC. Never remove the battery with metal tools or bend it when swollen. (A metal tool can puncture the outer skin and start a chemical reaction—we've accidentally done this when replacing old smartphone batteries and started some very small fires.) Swollen batteries also contain gases you don't want to breathe.

If you replace the battery yourself, be sure to pack it away as soon as you remove it. Do not throw the battery in the trash or anywhere else. This is environmentally friendly and poses a health risk to plumbers who may come into contact with the battery. Always dispose of batteries, inflated or otherwise, at an authorized battery disposal facility. Your system manufacturer can advise you on disposal processes and locations. Also, a quick Google search should lead you to a suitable place to dispose of batteries. You can also contact your local government and waste management authority for instructions.

Depending on where you live, big box retailers might also be the easiest route. "I recommend people take them to Best Buy or local [technology] retailers or even Home Depot that have [battery] recycling bins," says Jakes. "Even good lithium batteries wreak havoc in the waste stream."

Enjoy your devices and the performance that Li-Ion batteries and your new smart upgrades offer, but know that they should be treated with care and respect. If not, it could be more than a battery that needs replacing.