Hello fellow readers and fixers! Now, chances are you’ve seen a battery that looks swollen to the point that it’s about to pop. The techies among us refer to swollen batteries as ‘spicy pillows’. In fact, there’s even a whole subreddit that showcases pictures of swollen batteries!
Batteries come in various shapes, sizes and chemical compositions. They power all kinds of everyday things that we take for granted. But we often associate spicy pillows with “pouch” lithium batteries. These are the ones that power laptops and mobile devices.
Today, we’ll discuss what the term actually means, and how and why batteries can puff up overtime. We’ll also explain how you should safely handle a swollen battery.
What are ‘spicy pillows’ anyway?
Spicy pillows refer to the way lithium batteries in various mobile devices fail. These batteries are typically either lithium-ion (Li-ion), or lithium polymer (Li-Po) batteries. They rely on chemical reactions to produce energy for operating those devices.
Sometimes, something goes wrong that causes the battery to enter ‘thermal runaway’. This is where a battery gets too hot, as it can’t cope with the excessive current flow and dissipation. In turn, the heat damages the layers in the battery, causing gases to form inside. The gases make the cell(s) gradually inflate until it looks like a pillow. Hence, the term ‘spicy pillow’.
What causes batteries to become spicy pillows?
There are three main reasons why batteries become swollen:
- Age: As batteries get older, chemical reactions are more likely to go wrong when the battery charges. When this happens, flammable gases form inside, damaging the separators between layers inside the battery. In the process, this makes the cell(s) of the battery expand.
- Physical damage: Manufacturers usually make the outer casing of batteries for mobile devices using thin materials. If we don’t install them correctly, or drop or hit them in anyway, we risk rupturing that casing. As a result, this exposes the chemicals in the battery to the air, causing it to inflate, ignite or explode.
- Manufacturing defects: Sometimes, little flaws develop in the making of batteries. These flaws make the layers inside the battery less likely to properly remain separate while in use. As a result, this makes them more likely to become swollen while charging.
What makes spicy pillows dangerous?
Swollen batteries present a fire hazard, in that they can catch fire without warning. Flammable gases can escape out of the casing, due to splits or cracks created by the excess pressure. Gases may also vent and catch fire if the battery has sustained a puncture.
They are also an explosion hazard. Lithium is an alkali metal that violently reacts when exposed to air or liquid. That’s why we carefully store it in a vacuum, inert atmosphere, or in mineral oil or other inert liquids. Explosions can also happen due to bad product design. An infamous example of this happening is the Samsung Galaxy Note 7. Samsung recalled this smartphone from sale, after a small number of phones exploded. This was because the 3500mAh battery had no wiggle room in its recess, in case it became a spicy pillow.
Fortunately, batteries have safety measures built-in to minimise the risk of fire or explosion. As long as you protect it from heat and physical damage, it’s unlikely to vent gas or catch fire. Thus, spicy pillows are not inherently dangerous as long as you take proper precautions.
How do I know if I’ve got a spicy pillow?
You can find out if your device has a swollen battery by looking at the device or the battery itself. There are three main ways you can do this:
- Are any parts of your device out of alignment? Batteries exert pressure on neighbouring parts, pushing them aside as they swell up. You can see that this happens if there’s any gaps between parts of the case. It also happens with the displays on smartphones and tablets.
- Is any gas escaping from the battery? Gases from the battery are especially poisonous, and inhaling them can damage your lungs. Therefore, never directly sniff or inhale deeply from near the battery! Instead, keep a safe distance and gently waft the area near the battery towards you. If there’s a sweet, metallic smell, then gas may be coming out of the swollen battery.
- Does the battery itself look swollen? If you can easily access the battery without disturbing it, you can check the physical condition of it. Loose or wrinkled wrapping, a more rounded shape, or any lifting from its recess, are clear signs of a swollen battery.
What should I do if I’ve got a spicy pillow?
As soon as you notice a spicy pillow, don’t charge the battery in the device! Instead, disconnect it from the device if possible, put it into a fireproof container and take it outside. If your device has a sealed battery, try to discharge it as much as you can. Leaving your device turned on uses up power stored in the battery. This reduces the chances of a fire or explosion. You can back up any important data on the device to an external drive or microSD card while it discharges.
If your laptop or smartphone has an easy to remove battery, then you can simply remove the battery from it. On older smartphones and some newer ones, you simply pull off the back cover and remove the battery. For batteries inside laptops, the base cover on most of them has screws. You can unfasten these with a Philips screwdriver. They connect to the motherboard with a short cable from the battery itself. You unplug the cable, the remove the screws holding the battery to the chassis.
However, most smartphones and tablets have sealed batteries held in place with adhesive. If yours has a sealed battery, then we recommend taking the device to a repair shop. Technicians in repair shops typically have the necessary tools to safely remove swollen batteries. They will also help safely dispose or recycle them for you.
What not to do with spicy pillows?
First of all, never ever deliberately puncture a battery! Punctures can cause the battery to swell up, expel gas or catch fire. This video demonstrates what happens when a battery sustains a puncture:
Also, you should never put swollen or defective batteries in household waste. That’s because they may damage the environment if they go into landfill! Instead, take them to your nearest recycling centre or in-store collection facility. Just in case, you can cover the contacts or connectors with some tape. This keeps them safe while you take them there. You can find out where your nearest recycling centre is here.
Quickly summing up…
For more information, iFixit has a useful guide on how to handle a swollen battery. It’s useful for those of you with suitable tools and who really know what you are doing. Spicy pillows are very unlikely to blow up on you as long as you handle them safely. So until next time, keep calm and keep on fixing – oh, and remember, no popping pillows!