Of the common signs your battery is failing, a swollen battery is the most urgent and dangerous. Battery swelling happens due to a little thing called outgassing, which occurs when a battery gets overcharged, damaged, or simply old. Under those circumstances, the chemical reaction that keeps your battery running breaks down and, just like the name suggests, outputs gas. The battery casing is built to contain that nasty gas—so, inevitably, it bloats up.
From the outside, a swollen battery can manifest as a hazy white screen (due to pressure on the display). You might also notice a separation between the screen and the phone body, or “squishiness” of the screen (no separation between the phone and the screen, but your screen moves a bit when you pinch the edges of your phone). You can also detect a swollen battery by smelling your phone—not by holding it right up to your face like a flower (the toxic fumes are way worse than allergies, trust us), but by using a wafting motion from a short distance away. And if you want to triple-super-check, then you can also open your phone up and look to see if the battery’s wrapping looks loose or wrinkly, or if it looks round and is rising out of its recess.
Warning: It’s important to know that your battery is at risk of catching fire if it’s already reached a swollen state. Do not try to replace the battery if your device is unusually hot, smells really bad, or is already on fire. It can wait! If this all sounds a little too scary, and you’re not feeling totally comfy with the repair, that’s okay too—replacing a swollen battery can be intimidating. Take a deep breath, power down your phone, and then put it in a fireproof container and take it to a repair professional.
If your bravery has prevailed, and you want to do the replacement yourself—right on! Here are a few things you should do before the repair to ensure your safety: Make sure your battery’s charge is as low as possible by letting it drain to near zero percent—this greatly reduces the risk of a fire. Also, be sure to maximize the ventilation in the area where you’re doing the repair, to reduce exposure to those aforementioned fumes. And, your chemistry teacher is still right—wear eye protection (ideally full safety goggles). It’s also a good idea to wear protective gloves to prevent skin contact with the chemicals inside your battery.
Be sure to work on a non-flammable surface. In case a fire does break out, it’s a good idea to have a bucket of sand at the ready so you can douse it. You can also do the repair outside if it’s cool and dry, but if you’re inside, make sure to have an exit plan to outside in case your battery starts smoking or catches fire.
Wherever you repair, and whatever the temptation, do not expose the battery to water or moisture—the lithium in the battery can react with the water and cause more problems than you started with.
I’m going to reiterate that to make sure it really sinks in: DO NOT expose the battery to water or moisture—because the lithium will react with the water, potentially causing a fire.
Okay, now you can finally start to remove the battery. For the most part, you can just follow the repair guide for your specific device. We also recommend using a ‘lil solvent like iFixit’s adhesive remover, high-concentration isopropyl alcohol, or acetone. The solvent will reduce the need to pry against or flex the battery. But—and this is a big but—solvents are flammable, so use them as sparingly as possible, and acetone may cause damage to plastic parts. Only use dull, plastic tools to avoid puncturing the battery—punctures can release its toxic contents or start a flaming reaction. And, if things get a little smoky, take the device outside or place it in your fireproof compartment until it calms down. And then take a deep breath (away from your device and its fumes)—and try again. You got this.
Yay! You removed the battery! Now it’s time to dispose of it. Don’t throw it away or put it in water, please—recycle it. We’ve got an entire post telling you exactly how to do it, so please, please dispose of it safely.
After you’ve swapped in a new battery (we recommend using one of our kits, of course), here are some tips to take better care of it this time ‘round: Let your phone run out of battery slowly, and charge it slowly. This limits stress, lets the chemical reactions complete more fully, and keeps the device heat down. That means you shouldn’t have your phone hooked up to its charger when it doesn’t need to be, and try not to stop and start charging at short intervals. But most importantly, don’t drop the phone! Screen cracks are obvious, but drops can jostle or even puncture the battery completely invisibly, and that can be much more dangerous.
Unfortunately, lithium-ion chemistry isn’t perfect—all batteries are consumables, which means they get old. And like us, when batteries get old, the processes that keep them running start to degrade. But where we get wrinkles and breathe out CO2, batteries produce toxic gases and bloat themselves up to contain it—until they explode. So if you can replace your battery before it swells up, by all means do, but in case you don’t beat the bloat to it, we hope these tips help you feel more empowered to remove it safely.