Did you know that the smartphone you keep in your pocket has the potential to burst? A lithium-ion battery is the same no matter what device it's in, and they all carry identical risks.

What are these risks? Can your smartphone battery explode?

Smartphone Battery Explosions: The Facts

Smartphones are typically very safe. Yet, there is an association between smartphones and smartphone batteries exploding and smartphone fires. So, yes, your phone battery can explode. No, it isn't likely to happen.

Modern lithium-ion batteries, today's preferred rechargeable batteries for everything from smartphones to Teslas, can be highly explosive. Have a look at this thermal video of a lithium-ion battery cell during the thermal runaway process (which we'll discuss in detail in a moment):

The point of explosion is sudden and extremely hot. But outside of a lab where people apply an extremely hot source to the battery, how do smartphone batteries explode in the real world?

Here is the sequence of events that happen inside a lithium-ion battery before and during an explosion:

  • One area of the battery starts getting too hot due to a short circuit in the charging circuit or some other external cause.
  • The chemical reaction inside the hot area begins generating its own heat, which spreads to other areas in a process known as electrolyte overheat.
  • Eventually, this building heat causes the electrolyte to give off steam, which bursts the battery casing.
  • Very flammable, hot liquid (not unlike napalm) escapes and usually burns or melts the surrounding phone casing and whatever the phone is next to. The explosion and subsequent heat can start other fires.

This reaction, known as "thermal runaway," sounds horrendous, but there's one fact that should set your mind at ease: manufacturers are constantly implementing new safety features in lithium-ion batteries that reduce the likelihood of this happening, or at least reduce the damage caused when it does.

Additionally, thermal runaway is a chain reaction, and once it starts, it's difficult to stop, which is why the safety features are so crucial.

Smartphone Battery Safety Features

Some of the newer safety features manufacturers have integrated into lithium-based batteries include advanced sensors for better heat management and improved electrolyte compositions that are less likely to catch fire. These are in addition to the existing features like:

  • Non-flammable additives are added to the electrolyte and battery coatings.
  • Built-in circuitry that protects against current surges.
  • Circuit interrupt devices open the circuit if the cell pressure exceeds safe limits.
  • Fail-safe safety vents release gases if the cell expands beyond a higher safety limit.
  • Thermal fuses break the circuit when temperatures reach a safety limit.

So for a healthy battery installed inside the average phone, the worst-case scenario before the battery ever reaches this nightmare "thermal runaway" scenario is a message that the phone needs to shut down. Or the battery may simply stop working.

Still, some situations could still cause a battery to explode.

1. Dropping and Damaging the Battery

As mentioned above, everything will work fine so long as you are dealing with a healthy battery. One problem that can negatively affect a battery's health is physical damage from drops.

When this happens, most people will rush to a local repair center to get their screen repaired. If the phone still works, they don't even give a second thought to what damage the battery might have sustained.

Unfortunately, a drop can alter the battery's internal mechanical or chemical structure. These changes could cause any fail-safe circuitry to fail in extreme stress conditions.

How can you tell if a smartphone battery is damaged? Open up the case and take a look at the battery. If any of the following conditions exist, consider replacing it immediately:

  • Swelling
  • Deformation
  • Frequent, unexplainable overheating

However, it's important to note that with most modern smartphones, opening the case will void your warranty, especially if you attempt to tinker with a non-removable battery. Checking your warranty and contacting your smartphone repair service is advisable.

In many situations, you can avoid explosive battery failure by paying close attention to signs of existing battery damage. For a smartphone battery to be safe, all its built-in safety features need to function properly. So it's important never to use a battery with visible signs of damage.

You can also monitor potential changes to the battery using an app. There are several ways to check battery health on Android, while iOS users can check battery health right in the operating system.

2. Hot Temperatures and Environments

While there may be safeguards built into your battery to ensure that it sheds excessive heat or shuts down when too hot, it's important to keep the battery away from those temperature limits in the first place.

Many elements contribute to your phone naturally heating up, including:

  • Running intensive graphics that put a heavy load on the GPU
  • Using apps that put too much demand on the CPU
  • Widgets that constantly run while you're multitasking with the phone
  • Regular connectivity checks when your cellular or Wi-Fi connection is spotty
  • Long phone calls
  • Doing any of the above while the smartphone is charging

Normally any of these uses are fine, but if you're somewhere where it's hot, you could run into trouble. For example, using a phone in direct sunlight at the pool while listening to Spotify and browsing the web makes an already straining smartphone struggle to cool itself.

Even if this doesn't cause the battery to explode, it can contribute to aging and make it difficult to extend your smartphone battery life. Furthermore, charging your phone under these conditions can further contribute to overheating. The phone naturally builds heat during charging.

There are many ways to keep your phone cool and avoid these problems:

  • Remove the phone from its case when you're charging it.
  • Keep the phone out of direct sunlight whenever possible.
  • Don't leave your phone in a hot car for extended periods.
  • Don't charge the phone in a pocket, inside a bag, or any other place that can trap heat.

We've offered many ways to avoid overheating an Android phone and tips to keep your iPhone cool. Following these is an important part of being a wise smartphone user.

3. Using the Wrong Charger

A smartphone charger is a smartphone charger, right? You plug it in, and it delivers the juice to your battery. However, using the wrong charger is one of the fastest ways to damage your smartphone battery.

Many manufacturers ship a specific smartphone charger with your device (or, at least, they used to). But even if your new iPhone or Samsung doesn't arrive with a charger in the box, you should still pay attention to the type of charger you use with the device. Different power ratings, amperage, resistance, and fast-charging support can all make a difference to the charging quality and, consequently, your smartphone battery's health.

You can buy non-OEM chargers, but you need to ensure they meet all specifications required by your phone and comply with established standards like USB-IF. Cheap knockoff chargers use materials with sub-standard quality or an incorrect gauge of wire that lacks appropriate overcurrent protection. If you don't invest in a quality charger that complies with USB standards, you can run into charging problems at best. At worst, you're risking not only the destruction of your expensive phone but possible injury to yourself.

4. Getting Your Phone Wet

Lithium will ignite and burn when in contact with water or water vapor. Smartphone batteries are well-sealed, so that kind of contact shouldn't happen normally.

Many modern phones are waterproof or water-resistant. However, a smartphone with a damaged battery dropped into water accidentally is a recipe for disaster.

5. Battery Punctures

Lithium reacts to both water and oxygen, so puncturing a lithium-ion battery will produce a reaction. This could be anything from a little smoke and a terrible smell to a full-on explosion.

And the reaction is rapid.

Obviously, this means there's always a danger if a smartphone gets punctured during an accident or any other violent situation.

Your Smartphone Battery Is Very Unlikely to Explode

But never say never!

It's important to keep in mind that the battery inside your smartphone has the capacity to become a dangerous hazard under extreme conditions.

So the idea is to avoid those extreme conditions. Store, charge, and treat your smartphone in a way so that should anything ever happen, you are protected from serious injury.