Why phone and laptop batteries explode – and 6 ways to keep yourself safe

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ZDNET Highlights

• It is rare for rechargeable batteries to cause problems for the user.
• Rechargeable batteries are blamed for approximately 1,500 fires and 5,000 overheating incidents each year.
• Do not use any gadget that is damaged or showing signs of overheating.

Rechargeable batteries are everywhere.

Stop what you’re doing and think about all the things in your life right now that contain rechargeable batteries – laptops, smartphones, tablets, power banks, smart doorbells and surveillance cameras. And don’t forget to count your wearables: smartwatches, earbuds, and smart rings all have rechargeable batteries.

Then there are the batteries we put in our mouths and suck on – the batteries inside e-cigarettes and vapes.

Also: I tested solid-state portable batteries for a week – now lithium-ion seems outdated

And don’t forget that portable power station you have in your garage. That thing is literally a box full of rechargeable batteries.

I’m betting you have quite a few.

Right now, there are about half a dozen within my reach, and even more that live in my home, office, or car. And I’ve probably forgotten about that old smartphone in the back of the drawer or that old – possibly missed – power bank in my backpack.

For the most part, rechargeable battery powered devices behave incredibly well. This is actually a good thing, because most of us are happy to sleep every night with a charging smartphone just a short distance from our heads, and cramming ourselves into a plane to spend several hours at 40,000 feet surrounded by hundreds of different devices – all of varying quality and state of repair – that happen to have a rechargeable battery.

Also: Best Power Banks of 2026: Expert Tests and Reviews

But things can – and do – go wrong.

How dangerous are rechargeable batteries?

I pulled data from some sources, and it seems that rechargeable batteries are responsible for about 1,500 house fires and about 5,000 “overheating incidents” each year. E-cigarettes also cause hundreds of injuries each year, most of which, thankfully, are not serious or life-altering.

And every year, a story makes the news about a smartphone or wearable’s battery failing. Fortunately, most people walk away from such incidents with their hands folded and their eyes working. However, this does not change the fact that it could have been much worse, and we must remain alert and know what to do if we come across a battery that has gone bad.

A modern rechargeable battery holds a lot of power in a very small space. Most of the time, batteries do what they’re supposed to do – release that energy slowly and in a controlled manner. But if ever something causes the battery to release that energy suddenly, there is a risk of explosion and fire.

As someone who has witnessed many battery fires (some intentional, some unexpected), I have a healthy respect for how much energy we carry around in our pockets.

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Make no mistake, a faulty lithium-ion battery is incredibly dangerous, and also can do explosion. And when I say explode, I don’t mean the little pop of a party popper (although some explode in exactly the same way). An angry battery pack can go off with a huge bang, and it has so much energy that it shatters the equipment wrapped around it, sending a shower of shrapnel.

But you don’t have to worry about an explosion and the resulting shrapnel, as chances are you’ll find yourself in the middle of a spray of molten lithium metal and a thick, acrid cloud of suffocating toxic smoke.

And this enthusiastic chemical reaction is probably not going to happen when you’re outside, surrounded by fresh air, away from flammable materials, and when you have a fire extinguisher nearby. Oh no, it will happen when you least expect it. Perhaps when the device fits perfectly in your pocket, or when it’s on charge in the car and you’re driving at 65 mph on the highway.

Or when it’s on your nightstand, right next to your head – when you’re in deep sleep.

Why do batteries catch fire?

Again, thankfully explosions and fires don’t happen that often, but when things go wrong, it’s usually for one of the following three reasons:

1. Manufacturing Defect

A bad batch of batteries, a problem on the assembly line that caused a component to be damaged, or the use of the wrong components can cause all devices to fail.

Interestingly, while the media blames device fires and recalls on manufacturing issues, this is actually very rare due to the myriad of safety checks conducted by reputable manufacturers.

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2. Defective designs and counterfeit products

You usually only see this with cheap, poorly made devices. Some of these are made by manufacturers who don’t know what they’re doing, and others are made by firms who are clearly scrambling. Unfortunately, this stuff is flooding popular online outlets, and it can be difficult for the average person to tell the difference between a well-made product and a poorly made one as many times the devices carry counterfeit regulatory markings.

Many cheap and counterfeit products do not have the safety features that are included in products from reputable manufacturers.

3. Products damaged during use

The most common reason for products being unsafe is the end users. Throwing devices around, getting them wet, charging them with the wrong charger, and leaving them out in the sun to cook are all bad ideas.

Also: I changed these 7 settings on my Samsung phone to extend battery life by hours

Quality devices will include safety features to prevent overheating, overcharging, over-discharging, short-circuiting, and recharging from the wrong charger. Although these features work to protect damaged devices from becoming vulnerable, nothing is foolproof.

What can you do to protect your family from dangers?

I don’t expect you to have access to thousands of dollars worth of testing equipment; The truth is that you can recognize most threats without it. In fact, I can usually identify about 90% of unsafe products just by visual inspection.

By following a few simple rules, you practically eliminate all common causes of fire and explosion.

1. Buy designated brand products from reputed retailers. Yes, you might be paying a few dollars more for a good quality charger, cable or power bank, but it’s your life and the lives of your family members we’re talking about. Avoid too-good-to-be-true deals, social media deals and dubious marketplace sellers. If you suspect that you have purchased a cheap, poor-quality device, stop using it.
2. If an appliance is damaged in any way or shows any signs of overheating, swelling or distortion, stop using it. This applies to chargers and cords (even frayed charging wires can be dangerous). I recommend checking equipment annually and replacing damaged items immediately.
3. Do not allow devices to get too hot, especially while charging. Don’t charge the smartphone in your pocket or sports bag, and don’t leave it on the dash of your car while it’s baking in the sun.
4. Do not leave charging devices unattended. Well, most of us do, so at the very least, I suggest you don’t place charging items on or near flammable objects. A small lithium battery can instantly set a wooden table or piece of bedroom furniture on fire.
5. If you discover that a device has been recalled, follow the advice provided. Don’t be one of those people who think they can beat security.
6. If in any doubt seek professional advice.

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Don’t underestimate how quickly lithium-polymer batteries can catch fire and how dangerous they can be. Below are some videos that show how bad it can get:

What should you do in case of fire?

And if you are unlucky enough to encounter a burning electrical appliance:

• Don’t pour water on the fire! This will make matters worse and may lead to further fire. use only a suitable fire extinguisher Or fire blanket.
• Evacuate the building.
• Try to avoid breathing smoke.
• Call the fire department. Don’t be a fool or try to be a hero.
• Seek medical attention for any injury, no matter how minor.

I want to reiterate that electronic devices are overall extremely safe and not something you should lose sleep over. By purchasing a known brand name from a reputable outlet, and taking care that the equipment has not been misused or damaged, you are much less likely to have any problems.