Technology Explained

Why the Heck Were Samsung’s Batteries Exploding Anyway?

Derek Walsh 18-11-2016

The Samsung Galaxy Note 7 became infamous shortly after its launch in August this year when reports emerged of phones overheating, setting on fire, and even exploding.


Even though there were only 35 incidents out of more than a million phones sold, Samsung issued a full recall-and-replace order Samsung Recalls the Galaxy Note 7, Google Kills Project Ara... [Tech News Digest] Samsung recalls the Galaxy Note 7 over faulty batteries, Google shelves Project Ara, Apple is removing dysfunctional apps from iTunes, Instagram adds pinch-to-zoom, and why YouTubers are freaking out right now. Read More … until the replacements started exploding, too. Samsung has since issued a full recall on all remaining Galaxy Note 7 devices and even suspended production Samsung Kills the Galaxy Note 7, Because Boom! If you're currently in possession of a Galaxy Note 7, then you may soon be holding a very rare item in your hands. This is because Samsung could be planning to kill it off entirely. Read More .

Samsung Galaxy Note 7
Image Credit: Photomans via Shutterstock

But the Galaxy Note 7 is not the first device to be recalled for this reason, and it probably won’t be the last. In 2011, Apple recalled a batch Apple is Offering Free Replacement For 1st Generation iPod Nano [News] As rare as it is for Apple to publicly admit a malfunction, this one is too big to overlook. According to Apple, the batteries of some first generation iPod nanos may overheat and become a... Read More of its first-generation iPod Nano devices. In 2007, Nokia recalled 46 million phone batteries, and there have been more than forty other such recalls since 2002.

In this article, we’ll explore just what the heck is going on and whether or not you need to worry about this with your own smartphone.

Why Do We Use Batteries That Explode?

All of our portable electronic devices (i.e. phones, tablets, laptops) use Lithium-ion batteries. Pound for pound, Lithium-ion batteries provide far more energy than other types of batteries — around twice as much as Nickel Metal Hydride (NiMH) batteries and around six-times as much as the lead-acid batteries used in cars.


This is important in an industry where weight (or lack thereof) is a huge selling point. We all want our phones to be as light as possible yet still last at least a full day without recharging — and at the moment, Lithium-ion is the best technology we have that lets us do that.

Lithium-ion battery
Image Credit: Coprid via Shutterstock

But Lithium-ion batteries have a few disadvantages, too. They have a short shelf life, only lasting about 2–3 years from the date of manufacture, and that’s regardless of whether they’re actively used or not. If they fully discharge, they’ll never work again. And occasionally they explode.

To understand why this happens, it’s necessary to know a little about how Lithium-ion batteries work internally.


Like all modern batteries How a Battery Works and 3 Ways You Can Ruin It The modern battery is featured in so many of our favourite technologies that you could almost be forgiven for not spending time learning about their workings. Read More , they store and release energy through controlled chemical reactions. A current flows between two electrodes (an anode and a cathode) through chemicals called electrolytes. Lithium is highly reactive, which is what gives these batteries such a high energy density — but it also means that if something goes wrong, the results can be catastrophic.

So, What Can Go Wrong?

There are a few things that can go wrong with a Lithium-ion battery and they all involve overheating. If one part of the battery gets too hot, then it can lead to a chain reaction known as “thermal runaway” — the whole battery gets hotter and hotter until it ignites or explodes.

Because of this, Lithium-ion batteries have an on-board computer to ensure they don’t overheat. If this fails then overheating can occur, especially on a hot day or when the device is being heavily used. Overcharging can also lead to overheating, but again, the battery’s internal computer should prevent this. Unfortunately it may fail to do so, whether due to a manufacturing error or because the computer itself has sustained damage.

Burnt out smartphone
Image Credit: wk1003mike via Shutterstock


The anode and cathode also need to be kept separate or the battery will short circuit, redirecting energy to the electrolytes. In a Lithium-ion battery the electrolytes are highly flammable, and fire or explosion is all but inevitable if this occurs. Why would the electrodes ever touch? Again, maybe because the battery sustained physical damage or because of a manufacturing error (e.g. a defect in the material that separates the electrodes, the introduction of a foreign conducting material, etc).

Misusing or abusing the battery can also cause an explosion. Piercing the battery with a sharp object can cause a short circuit, while connecting it to an incorrect charger can cause it to overcharge or charge too quickly, which can lead to a build up of lithium on the electrodes, a short circuit, and ultimately an explosion.

What Went Wrong for Samsung?

It’s not yet clear exactly what the issue was with the Galaxy Note 7. The company has blamed “a very rare manufacturing process error” which caused the anode and cathode to come into contact. Further investigations are underway. Samsung has stated that none of its other products are affected by this issue, and there have not been a significant number of incidents involving their other products.

Remarkably, some people have decided that the Galaxy Note 7 is such a good phone, they’re going to hold onto theirs Some Idiots Are Keeping Their Exploding Samsung Phones In case you missed the news, the Samsung Galaxy Note 7 is dead. And yet some Galaxy Note 7 owners are refusing to give up on their favorite smartphone. Idiots. Read More  despite the risk. This is, to say the least, a rather reckless approach, and while the risk is small, it’s unnecessary to take it. There are plenty of good alternatives 5 Non-Exploding Samsung Galaxy Note 7 Alternatives Looking to avoid a fireball in your home? You may need some Samsung Galaxy Note 7 alternatives. We've rounded up five of the best Note 7 alternatives which range in cost from $360 to $610. Read More on the market, including some of Samsung’s other products.


Should You Be Worried?

Although the consequences of an exploding battery can be catastrophic, it’s an extremely rare event.  You’re more likely to be struck by lightning  — which would probably also cause your phone to explode! But there are some steps you can take to reduce the odds even further:

  • Only use the original battery, or one from the manufacturer, or a reputable brand.
  • Don’t leave your device in hot areas, particularly while charging. Keep it out of direct sunlight, and make sure it can dissipate heat effectively.
  • Have a protective case for your phone to avoid puncture damage if you drop it. But take the case off if the phone gets too hot. The phone will almost certainly shut down before the battery gets hot enough to ignite, but the heat can still shorten the life of the battery.
  • Do not use a cracked or swollen battery. Remove it from any device and do not attempt to charge it.
  • Dispose of old or damaged batteries responsibly. Take them to a recycling center, or to a electronics retailer who will be able to dispose of them properly.

Until there’s a breakthrough in battery technology Battery Technologies That Are Going to Change the World Battery tech has been growing more slowly than other technologies, and is now the long tent pole in a staggering number of industries. What will the future of battery technology be? Read More , we’ll be using Lithium-ion batteries on a daily basis. And the vast majority of us will never encounter a problem more serious than running out of power. If the Samsung debacle has you concerned, take care and know that you have pretty much nothing to worry about.

Did you buy a Galaxy Note 7? If so, are you one of the mavericks who’s keeping theirs? Have you ever encountered a battery explosion? Let us know in the comments section below.

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  1. David Clark
    November 28, 2016 at 2:25 am

    Tucking a skinny phone like anything made in the past 5 years in an ass pocket is totally begging for issues of a huge variety. Really, folks.

    • Derek Walsh
      November 30, 2016 at 3:02 pm

      True. It's generally a bad idea to keep a phone in your back pocket, and sitting on a phone - particularly a very thin one - could cause the battery to short, with painful consequences!

  2. Vys
    November 23, 2016 at 2:46 am

    Just a quick curiosity surge, but if the problem is entirely due to the batteries, why doesn't Samsung just provide free battery change? We all know that we should only use original batteries, but Samsung is the manufacturer, their replaced batteries should be perfectly compatible with the devices.

    • Derek Walsh
      November 23, 2016 at 11:52 am

      It's not clear at the moment, but given that there were problems with the replacement batteries too, Samsung obviously wasn't able to solve it. At this point, consumer confidence in the product has gone, so Samsung may feel it's better to write off the Note 7 completely rather than spend time and money fixing the battery manufacturing process.

  3. Jay
    November 21, 2016 at 12:05 am

    When consumers require more technology in a smaller package the battery suffers from anorexia. The battery has been designed too small for the load the phone and all it's functions produce simply to make more space for the increase in technology.

    • Derek Walsh
      November 21, 2016 at 4:05 pm

      This is true. The need for thinner batteries means the anode and the cathode are closer, which increases the chances of them connecting, whether due to the presence of impurities or an external force.

  4. Ronald DeRemer
    November 20, 2016 at 12:15 am

    I think the life is more than 2-3 years. Many EV's using LiIon batteries are lasting much longer.

    • Derek Walsh
      November 21, 2016 at 4:13 pm

      The batteries used in electric vehicles can last upwards of five years, depending on usage. The ones used in phones and laptops will rarely last more than two or three years.

  5. Alex
    November 19, 2016 at 5:36 am

    I had a Note 7 for just 11 days untill the first recall was issued, I had the hope than the problem will be solved but, I better came back to the Note 5 with has no issues (instead of the S7 replacement, is not the same as a Note). And yes, I'll buy the Note 8, but a couple of months after release to avoid any other recall.

    • Derek Walsh
      November 21, 2016 at 4:07 pm

      That seems like a sensible option. There are no reported problems with any of Samsung's other products, and the Note 8 is likely to have the most extensively tested battery in history!