There are multiple reasons why a lithium-ion battery may swell. There is usually one underlying cause for this to happen, though. Batteries usually swell because gas builds up, creates pressure, and expands them.
With that in mind, we must consider the more common causes for a battery to store gas. Manufacturer defects can happen. If the battery maker doesn’t make the battery correctly, gas can slowly build up during the charging process. This essentially means simply charging your phone enough times could be an issue, especially considering juicing up your phone also creates heat.
Heat commonly speeds the process, too. You should probably make sure not to leave a phone in the sun too much, or next to very hot items.
Additionally, physical damage to the battery can be a very common cause of battery swelling. Have you ever dropped your phone? Maybe you accidentally punctured the battery? This could be why your battery is swelling. Not to mention, batteries get old, too. Chemical reactions can change, and parts weaken.
By the way, this shouldn’t be a common occurrence. Unless there’s a severe manufacturer defect, most batteries should last the couple or few years most users keep a device.
How to know if your phone battery is swollen
It’s much harder to tell if your battery is swelling these days, as handsets with removable batteries are becoming very scarce. We never really see our batteries anymore. This makes it harder to identify a swollen or damaged battery.
The easiest way to tell if a battery is swollen is by inspecting the device (or battery, if you can). Are there any bumps? You may notice an unusual wobble when you lay it on a flat surface. Also, look for warped shapes or signs of the phone disassembling itself. Smartphone backplates start to come off as the battery’s swollen shape puts pressure against them.
While not as safe, the smell can also signify a swollen battery. We wouldn’t advise that you actively try to inhale chemicals, but this is something you may have accidentally noticed already. Does your phone smell odd? People describe a bad battery smell as metallic, and sometimes even sweet.
Even simple things like battery performance can be a dead giveaway. If your battery is charging too slowly, or the charge isn’t lasting as long as it should, this may be a cause of concern.
What to do if your phone battery is swollen
So you’ve found something odd with your smartphone’s battery. Is it safe to use a swollen phone battery? Definitely not! A swollen lithium-ion battery can be very dangerous. The pressure can make gases escape, and the battery can even catch fire or explode, especially if pierced.
Your first step should be to turn off the device immediately, and keep it off. Don’t plug it in or mess with it, either. Leave it in a safe place and keep it there, preferably away from anything that can burn.
A swollen lithium-ion battery can be very dangerous!
If it’s possible, and safe to do so, you should probably remove the battery. Just be careful not to mess with it too much in the process, and try to avoid smelling any fumes it may give off. We actually recommend taking the phone to a professional instead. Technicians will have the necessary knowledge and tools to do this easily. They can also find a suitable replacement for you. This will likely incur some charges and require replacement purchases, though.
If your phone is still under warranty or has insurance, your best bet is to go with the carrier, retailer, or company handling the coverage.
How do I stop this from happening in the first place?
Well, you won’t always be able to stop this. That’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 stumbling across a bulging battery in the future.
Don’t let your gadgets get too hot
High temperatures can speed up the rate at which the electrolyte goop decomposes, which could contribute to gases building up inside a battery. And even if that heat doesn’t make a battery bulge, Mitlin says, it will definitely take a toll on how well the battery will work down the road.
Thankfully, many of your gadgets include features to prevent them from running at high temperatures for long periods. Your phones, for instance, will warn you when they get too warm — once that happens, they’ll start to shut off certain features and dial down the brightness of their screens. Worst-case scenario, they’ll shut themselves off entirely until they cool down.
Laptops are generally better at dealing with heat because they have built-in cooling systems, but with summer right around the corner, you should make sure not to leave any of your tech in a hot car or under the sun for very long.
Keep an eye on batteries’ charge levels
Keeping a battery at a high state of charge is a great way to put extra wear on it, so do your tech a favor: Don’t keep it connected to a wall outlet all the time. The opposite is also true: For slightly different chemical reasons, that all-important electrolyte goop also degrades when a battery is fully dead, according to Viswanathan.
That’s right. Keeping your gadgets fully charged and fully dead could contribute to battery swelling over time.
Advice: Once your gadget’s battery hits 100 percent, unplug it and use it as you normally would. Then, once you get down to the 10 to 20 percent range, charge it again.
Try not to drop anything
We know it’s easier said than done.
Usually, if your laptop tumbles out of your hands, the first thing you would worry about is whether its screen is still in one piece. But Viswanathan says these kinds of tumbles could lead to situations where one part of the battery is getting more charged than others. That could lead to battery swelling, as well as some other less-than-pleasant outcomes.
Some devices, like certain laptops, are more vulnerable to this than others because of where their batteries are stored. If your laptop has a battery you can remove yourself, it might be worth keeping it in a protective sleeve when you run around with it. Ditto for phones and tablets: A good case should help keep everything, including the battery, from getting banged up too badly.