An alarm blares in your ear, and you turn over, slapping
the off button as you swing yourself out of bed.
You slip into some workout clothes, pocket your AirPods, and rub the
sleep from your eyes, before snatching your phone off its charging dock.
It’s been charging all night, and you can feel how hot it’s gotten.
Weird, you think, but you put it out of your mind.
When you get to the gym, you make a beeline for the treadmill.
You pop your headphones in and put on
your workout playlist before zoning out.
After a short time, you detect the acrid
stench of smoke limps into your nostrils.
You stop running, confused, thinking it
may be the treadmill, or is it your phone?
Suddenly, you notice your left ear is hot.
Which is very strange.
Before you realize what’s happening, you hear a
deafening BANG, before the world vanishes in black.
When you awake, all hearing from your left side is shot, and
doctors explain, in loud voices so you can hear them, that
one of your AirPods shorted and exploded inside your ear.
But how does that even happen?
And are we all sticking ticking timebombs into our ears?
On February 8th 2018, Florida resident Jason Colon was working
out at a local LA Fitness when he felt his ears heating up.
He also smelled the acrid scent of burning.
Suddenly, one of his Apple AirPods turned
off, music still blaring out the other.
Jason took out both pieces, and found that
the right earbud was smoking slightly.
He set them down before going to find gym staff, but when
everyone came back, they found the earbud had burst, cracking
the casing, leaving scorch marks on the white plastic.
After finding out what happened to his earbuds, Jason shuddered
thinking about the damage if he hadn’t taken them out.
“I don’t know what would’ve happened to my ear, you know,
but I’m sure that since it hangs down I mean it could’ve
been my earlobe, you know my earlobe could’ve got burnt.
It was the craziest thing I ever went through.”
After the incident, Jason suggested that it could’ve
been caused by a malfunctioning battery in the earpiece.
An Apple spokesperson assured the public that they take these kinds
of malfunctions seriously and are working out the issue already.
But not everyone is as lucky as Jason with their sparking AirPods.
On May 19th, 2020, 23 year old Chinese man Zheng Tang, suffered
injuries on his right ear when his AirPods heated up and burst.
Information on the accident was posted on Chinese social media
site Weibo, and included what claimed to be a report from
the First Affiliated Hospital of the Zhengzhou University.
The report alleged that the skin of Zheng’s
right ear canal was ruptured by the explosion.
Luckily, Zheng’s ear improved after a couple days of
treatment with anti-inflammatory drugs, however he
still has to deal with some hearing loss and pain.
Upon revisiting his doctor, they found some
swelling in his ear, and some fresh blood.
Not only that, but they also noticed a crack on
his right ear canal about 1 centimeter in length.
That said upon inspection of an image of the damaged
AirPods, no clear fire damage can be seen, and only a small
crack can be observed where the shaft meets the earpiece.
Apparently, the earbuds were bought in a mall for about 180 US dollars,
or 1276 Yuan, and like Jason Colon’s incident, Apple assured the
public that they’re conducting further investigations into the problem.
AirPods aren’t the only technology with
a history of bursting into flames though!
You might remember the Samsung Galaxy Note 7 debacle back in 2016.
Since the release of the device, the United States Consumer
Product Safety Commission found that Samsung received
reports of 92 overheating batteries, 26 burns, and 55 reports
of property damage including fires in cars and garages.
However Samsung has only acknowledged 35 of these incidents.
After the incidents, the CPSC demanded
Samsung recall more than 1 million units.
There was a class action lawsuit, however it was thrown
out in court on the argument that Samsung did their
due diligence to protect consumers by issuing a recall.
According to Wired, the exploding phone issue was due to
compounding problems from two different battery suppliers.
Batteries sourced by Samsung SDI did not have enough room between
a heat-sealed pouch around the battery, and its internal parts.
This defect made it easier for the battery
to short circuit, potentially causing a fire.
Other batteries sourced by Amperes Technology Limited were
missing key insulation tape, which could keep the heat down,
and some of the cells inside the battery had sharp edges
that could puncture the wall between the two sides, again,
increasing the risk of short circuiting and bursting into flames.
Samsung tested over 200,000 devices and 30,000 batteries at a
massive charging facility specially built to fix this problem.
D.J. Koh, Samsung Mobile communications chief, notes that a
team of 700 engineers conducted internal testing, while other
organizations conducted their own independent tests as well.
Ok, well AirPod and smartphone batteries
can explode, but like, that’s all, right?
Right?
Well, when Steve Paffett was woken in the middle of the
night in March 2018, his business’s intruder alarm blaring
in his ears, he was horrified to find that Allplas, his tarp
and netting store in Letchworth, England, was lit ablaze.
Paffett watched helplessly through his CCTV app on his
phone as flames licked at the ceiling above an office desk,
leaping from the HP laptop he’d left charging overnight.
“It was awful” he said, “I was watching a bonfire on my office desk”.
Fortunately, Paffett’s insurance was enough to cover some of
the damages, but much of his stock was damaged beyond repair.
Now, he warns others against leaving
lithium batteries charging indefinitely.
Paffett said “I don’t think anywhere near enough of
us are aware of the potential ‘bombs’ we have indoors.
I was sat at that seat earlier that day and I swear
it would have taken my face off or killed me.”
HP issued a recall for the batteries in January 2018, but
it’s unclear if Paffett was aware of the recall and the
danger, which highlighted inefficiencies in how consumer
protection groups communicate key information like recalls.
Laptop and phone fires are one thing, but that’s the worst of it, right?
So not only are the Lithium batteries in our handheld
devices going up in smoke, but new electric motor
vehicles likewise make use of Lithium batteries.
They’re a little bigger than the ones in our phones though.
Tesla-fire.com tracks different incidents of Tesla EV fires,
and you’ll be happy to hear that of the 182 incidents that
the website confirmed, 50 of them were spontaneous combustion
of the battery while the car was parked and shut off.
Woo safety!
Incidents like those on a California
freeway in January 2023 are all too common.
A Tesla spontaneously burst into flames.
The Sacramento Metropolitan Fire District said that nothing unusual
took place leading up to the fire, but the battery cells underneath
the suspension burned long after firefighters began soaking the flames.
All in all, the fire department was forced to use
over 6000 gallons of water to put out the inferno.
Likewise, some E-Bikes are suffering from the same issues.
Since the beginning of 2023 in New York City alone residents have
seen at least 30 fires, 40 injuries, and 2 deaths as of February 27th.
In 2022, E-bikes were behind 216 fires, and Lithium-ion
batteries became the fourth leading cause of fire
deaths in New York City according to the FDNY.
The amount of fires from E-bikes is climbing, primarily
because we’re importing more E-bikes year by year.
The US imported about 1 million in 2022,
880,000 in 2021, and only 450,000 in 2020.
In all odds, we’ll continue to see this number
increase as E-bikes, and electric vehicles continue
to grow in ubiquity in North America and beyond.
Ok, so it’s obvious that Lithium-ion
batteries have some… fire issues, but why?
First, let’s cover how batteries work.
The first “battery” was made in 1780 by Alessandro Volta.
Volta, volt, get it?
He spoke to another scientist, Luigi Galvani, who found that
if you hung the bottom half of a frog from an iron or brass
hook, the legs would twitch if touched with another metal.
He believed that this was caused by the
movement of electricity inside the animal.
Volta was impressed, but he believed that the movement was
caused by the metal, not inherent electricity inside the frog.
Volta conducted more experiments and discovered that stacks
of silver and zinc, wrapped in cloth and soaked in saltwater,
would transmit an electric current if you put wires in each end.
Batteries today work a little better than the Voltaic Pile, but they all
still work using the same chemical reactions as they did 300 years ago.
All batteries have a negative side—an anode, and a
positive side—a cathode, as well as an electrolyte
substance with a semi-permeable barrier between each side.
When the anode and cathode are submerged in the electrolyte,
a chemical reaction occurs that attracts negatively
charged electrons from negative to positive, which in turn
attracts positively charged ions from positive to negative.
Electricity, at its very simplest, is the
movement of electrons from one place to another.
So as electrons go from anode to cathode,
they can power your device as they go.
However, there needs to be an equal
exchange so the charge can balance out.
This is where the electrolyte comes in,
the salt water from Volta’s experiment.
The electrolyte allows for the transfer of positively
charged ions from the positive side of the battery to the
negative, through that semipermeable barrier we mentioned.
When the charge on each side of the battery is
equal, and all of the electrons have moved from
negative to positive, then the battery is done.
It’s “dead”.
Most batteries we encounter on a day to day basis are alkaline
batteries, which means that the electrolyte inside is corrosive.
This is why the old batteries in your XBox 360 controller burst and
leak, leaving that gross residue your mom told you not to touch.
There are lots of different kinds of batteries, and the
main difference between them is what materials are used.
Different anodes, cathodes, and electrolytes can impact the
voltage, longevity, and rechargeability of certain batteries.
We typically use one of 3 different kinds of batteries day to day.
Alkaline, which is the oldest, Lithium Ion, the newest type, and
finally, Nickel Metal Hydride Batteries, which were invented in the 60s.
The main benefit of Nickel batteries at the time is that
they were rechargeable, whereas Alkaline batteries are not.
However, Lithium Ion batteries charge way faster, hold more
charge, and they can be charged many many more times than Nickel.
They’re far more expensive, however the benefits
vastly outweigh the cost, so they’ve become the
main way we store energy for our devices today.
Lithium Ion batteries became popular in the early
1990s as many major tech companies adopted their use.
In a Li-ion battery, the negative anode is made out of carbon,
and the positive cathode is made out of lithium cobalt oxide.
Unlike alkaline batteries, lithium ions
can move both ways through the electrolyte.
When you charge the battery, those same lithium ions move
back to the positive side, creating a new charge differential
which attracts electrons to their original negative end.
Li-ion batteries are the best batteries
we have so far, but they’re not perfect.
They’re starting to degrade as soon as they leave the factory, and
they’re only good for 2 to 3 years regardless if you use it or not.
Not just that, they’re extremely sensitive to hot temperatures,
degrading much faster than they normally would when they get hot.
On top of that, if you fully kill the battery, that
is, run it until it’s dead dead, then it’s ruined.
Li-ion batteries also need microcomputers which
control the transfer of power, ensuring that the
battery does not totally discharge itself by accident.
This adds to the cost though.
And lastly, there’s a small chance if the battery
is damaged or fails, that it can burst into flames.
None of this explains why batteries explode though.
There’s a chemical reaction going on, but
how does that result in a flaming inferno?
The problem is that these batteries create the perfect
environment for fire, aka, heat, fuel, and oxygen.
The ingredients in the electrolyte are “organic
solvents”, and they act as a fuel source.
The cathode in Li-ion batteries contains oxygen.
And finally, these batteries generate
heat, and there’s our final ingredient.
Ok, but if all Lithium Ion batteries have all 3 ingredients
for fire ready to eat, why don’t they all combust all the time?
Well, it helps to know why they do explode in the first place.
The vast majority of Li-ion batteries are made to fit into tiny compact
spaces, so the components of the battery need to be even smaller!
These parts are extremely fragile, and encapsulated
in very thin partitions which can be pierced easily.
If these partitions are damaged, then
a spark can occur, triggering a fire.
Fire increases heat, which speeds up the chemical
reaction, which creates more fire, which increases heat,
which speeds up the chemical reaction, which creates more
fire, which increases the heat, and you get what I mean.
Sweet, sweet thermal runaway.
The catastrophic end of this story is that when the heat
generated inside the battery cannot be dispersed in a controlled
manner, it’ll find a way to do so in an… uncontrolled manner.
BOOM!
That said, Lithium Ion batteries have been designed with specific
safety features to ensure that these explosions don’t happen.
All batteries are pressurized, so they
need to be contained within a metal casing.
If thermal runaway begins, these metal casings are equipped
with pressure sensitive holes which can release excess
pressure to, ideally, prevent a catastrophic failure.
If the pressure inside the battery increases to over
3,000 kilopascal, which translates to 435 pounds per
square inch, then the valve will begin venting pressure.
Of course, if the thermal runaway “runs” faster
than the vent can release pressure, then…
Boom, again.
Remember the semi-permeable barrier in the electrolyte?
Well, in Lithium Ion batteries that barrier is made
up of a material called polyolefin which acts as
a fuse shutting down the battery in an emergency.
When the battery heats up too much, specifically 130 degrees
celsius, this barrier melts, preventing ions from moving
back and forth, disrupting any potential for thermal runaway.
One last safety mechanism is called a
Positive Temperature Coefficient, or PTC.
It’s a grouping of materials that increase
their electrical resistance when they heat up.
Conductivity is how well electricity flows through a material,
and resistance is how well a material can resist that flow.
Copper wire is conductive, and the
insulation around the wire is resistant.
PTC is a material that loses its conductivity as it
heats up, to avoid any cascading failures because
of an effect called “Elevated self-discharge”.
See, all batteries, since they’re based on
chemical reactions, lose their power over time.
If the battery is old, used, or stored in a hot
place, the rate of self-discharge can increase.
Elevated self-discharge can occur under those
conditions, but it can also occur after a short circuit.
PTC cuts off that major electrical short before the
heat can increase to the point of thermal runaway.
Because these materials increase resistance as they heat
up, the moment temperatures begin to rise, they cut off the
flow of electricity anywhere there isn’t supposed to be.
Now, of course, sometimes everything goes wrong all at
once, but there are little things we can do to not only
keep ourselves from, well, spontaneous combustion, but
also generally maintain the health of our devices better.
It’s best not to allow any devices that use Li-ion batteries to
fully run out of power, or to continue charging after it’s full.
One, both these things will hinder your battery’s
effectiveness, and two, overcharging increases heat
which, as we know, can trigger thermal runaway.
It’s also best not to store devices that use these batteries
in close proximity, like in a bag all bundled together.
This doesn’t necessarily increase the initial chance of fiery
disaster, it just makes the first disaster turn into multiple.
If you see any deformities like cracks, dents, protrusions, or
other damage on a battery you should immediately discontinue using
it, and dispose of it safely according to local waste guidelines.
However, the majority of Lithium Ion batteries are contained inside
devices and are literally inaccessible to consumers safely and legally.
Tampering with a device to check if the battery
is safe, will most likely void your warranty, and
risk damaging the battery if it isn’t already.
So, unless your device has clear instructions for the
removal of a battery, do not attempt to remove them.
And lastly, do not store batteries in
places exposed to high temperatures.
Some places are obvious, like a hot car in the summer, but some
are more mundane, like laying your laptop on top of a blanket
on your bed so the fans can’t cool the internal mechanisms.
I’d be Li-ion if I said that these batteries never explode, but if we
try to pay attention to recalls, and treat our electronics right, it’s
easy to keep ourselves safe from fiery cell phone and AirPod explosions.
We just need to be mindful of the hottest new
tech trends, and just how hot they can really get.
Based on our last video we put a poll on
Twitter asking, “Are you afraid of needles?”
One Twitter user commented, “I’m not afraid of
needles, but I certainly don’t like them...”
Hmm I see your ‘point’, you're just not ‘sew’ into it.
65% of you aren’t afraid of needles it ‘seams’.
Well that’s a lot of you who haven’t seen our video about a girl who
had a needle disappear inside her and wasn’t found until 10 years later!
Click the video on your screen if you’re
piercingly curious to hear more about that story.