I’m sure most people have heard about the Samsung Galaxy Note 7 phones catching on fire as it has received quite a lot of media attention. I bought one of these phones due to the fact it has USB-C with USB 3.1 speeds, it’s waterproof, and it’s an all around great phone. Shortly after owning the device, a recall was announced as the batteries were deemed faulty–there was a manufacturing defect and the plates in some batteries were bent–the fault was observable under an X-Ray. Since then, a second recall has been announced and at the time of writing this, Samsung hasn’t explained why; I read somewhere that they don’t know what the fault is but I don’t know how true this is. I believe I know what the fault is.
If my theories are correct, the statistical anomaly would be explained
If you’re unwilling to read all of this, then my theory is that the explosions are related to a fault within the phone causing it to crash, e.g. faulty RAM or a faulty CPU. The crashing creates heat, and this is escalated by the fact the heat dissipation is relatively bad due to how crammed the electronics are and the insulation provided by the glass front and back. Normally it wouldn’t matter because thermal throttling sets in, but this might not work perfectly when the phone crashes.
If my theories are correct, then it would also explain why we have not heard about anymore fires after the recall has been announced. Phones that were behaving unreliably and were altogether a nuisance would have been returned. Whereas the devices that seem to be working flawlessly, people are less likely to return.
There might still be the odd phone that catches on fire but I would really, really like Samsung to look into the devices that have been crashing and see what happens.
If anyone knows anyone that’s had a phone catch on fire, please ask them if it had been rebooting or acting strange prior to the incident where it burst into flames.
The Apple iPhone 7’s are at it as well
I have read of a few cases where the Apple iPhone 7 has “exploded”. Some people on internet forums find this endlessly hilarious and it’s somewhat saddening. In my opinion, the fires are more than just a fire; they highlight something much bigger than one little “explosion” (I’m using quotes because I think of bombs as explosions.) The Samsung Galaxy Note 7 was far from the first phone to catch on fire, in fact, the original Apple iPhone did too.
Please excuse my verbosity with this article, but in order to explain I am someone that knows a little about this subject, I have to tell a somewhat convoluted story.
As a radio controlled 3D helicopter pilot, I have seen these types of fires before. I don’t fly these helicopters anymore, but long before the Apple iPhone was invented, us hobbyists would seek ways to make our helicopters either more powerful or lighter weight. My attitude was there’s no replacement for displacement, but making a lighter device does generally give better options for 3D flight. I digress…
The larger, 6 foot helicopter of mine in the photograph above, used a nitro based fuel engine, but when your servos (the little motors that move things) have to pull multiple kilograms due to the wind resistance (these things fly quite fast–if you’re lucky, you can get about 100mph out of them), you still need quite powerful batteries. More specifically, you need a battery that can deliver a high-ish voltage and a high current. There are also some helicopters that use electricity to power the rotors, such as the little one in the photograph.
Long before the Apple iPhone was created, I’d seen sheds burn, helicopters turn into balls of flames and batteries fail due to misuse. Radio controlled hobbyists are pretty obsessed with batteries. The chargers are considerably more fancy than anything you’ll find for a phone, for example you can select the exact voltage and the amperage for each cell. The batteries themselves are, I believe, built to a higher standard and people give a lot of thought into these devices. If you think an Apple iPhone 7 costs a lot, you wouldn’t enjoy crashing a $5,000 helicopter.
People soon learned to treat their batteries carefully when mishaps happened. We had learned to charge them correctly, to store them correctly, to discharge them correctly, and most importantly, to physically put them in a logical place on the helicopter. With my radio controlled helicopter, I used velcro so the battery could move. I placed it in foam, and I made sure it wasn’t flush with the very front of the helicopter. If I could learn as a youngster, then I believe these large companies should be able to learn from this too.
Phone’s are designed with such small tolerances; are crashes taken into consideration when heat dissipation is measured and analysed? What if the phone has crashed and it is being charged?
With an ideal flight, excluding the centre of gravity change, the battery could be almost anywhere on the helicopter. With a crash, it made a huge difference.
Not all Lithium batteries are created equal
There are multiple types of Lithium batteries. Typically when we say Lithium Ion, we mean something different to a Lithium Polymer battery; technically speaking, they’re both Lithium Ion batteries. There’s also a newer battery called Lithium Ion Phosphate (LiFePO 4.) Lithium Polymers can deliver an incredibly high current but they are more volatile than a standard Lithium Ion battery. Not only can they deliver a high current, but they can also receive or be charged by a high current. It is likely that they are used for this reason; companies can state their phone charges extremely quickly, and in my opinion, this is their first mistake.
One thing that remains true with these batteries is if you over-charge, short, over-discharge, charge at the wrong temperature, crush, bend, apply too much heat or generally mistreat these Lithium batteries in some way or other, they will catch on fire.
The customer is partly to blame
The customer doesn’t want a large charger that can apply a specific voltage and current to specific battery cells; the customer wants a small charger that can charge the battery quickly and be unplugged easily. These inferior chargers change the rate at which they charge based on the internal resistance of the battery; the internal resistance changes based on how charged the battery is. So long as the device charges okay, the average customer won’t care. So long as the device is cheap to make, the manufacturer is happy.
The customer doesn’t want a large water cooled phone with o-rings and counter-sunk screws; they want a lightweight device, that can be used as a desktop computer, a DSLR camera and can make phone calls to aliens, while taking a dive in the ocean. Excuse the exaggeration, but my point is that we crave these tiny devices that can do so much. Many people think of these phones as good build quality, but since when was glue considered “good build quality”? It’s the equivalent of using duck-tape to seal a pipe. I want waterproofing but I want it to be done properly e.g. o-rings instead of glue.
Lithium Ion Phosphate batteries are slightly more stable than Lithium Polymers; they can deliver a high current but you won’t be able to charge the phone quite as quickly. In my opinion, these should be considered. People won’t be able to brag about the “charge your phone for 2 seconds and get 80 days battery life” but is that really needed? The customer may not know better, but I believe the manufacturer should.
My theory regarding why the Samsung Galaxy Note 7’s have been catching on fire
I do not have proof of what I am about to write and I do not want to get sued for writing any of this; it is just a theory of mine:
I believe the latest smartphones are crammed to the point the batteries literally don’t have room to breathe. That’s fine under an ideal circumstance, but if the phone has a problem unrelated to the battery, it can equate to the battery catching on fire. The glass front and back makes sense because it’s pretty and it doesn’t prevent magnetic induction from working, but it is an insulator and for that reason, I think it is potentially terrible.
The first Samsung Galaxy Note 7 of mine would crash, and when it would crash, it would get extremely hot–almost as if the CPU was running at 100%. I believe if the phone were to crash, get hotter and hotter because of the glass insulation, and the battery were to expend, then I think the battery would catch on fire. I didn’t allow this to happen, but I did feel it get piping hot when it were charging.
A manufacturer can implement cut-off technology, thermal throttling and whatnot, but what happens if those features fail? A device shouldn’t rely on fail-safes like that, but instead, it should be fool-proof.
To prove my theory is correct and the fires are related to phones that crash, in my opinion, Samsung should sort the recalled phones into two groups–those that have been crashing (this might be down to a CPU or RAM fault rather than a battery fault), and those that haven’t. From there, they should begin to examine the faulty phones and watch what happens when they crash. Measure the temperature of the phones and draw objective conclusions rather than X-Raying a battery and assuming that same fault is why specific phones have been catching on fire.
I believe certain design changes need to happen to phones. It’s no good just saying “the batteries are to blame!”, that’s like blaming the fuel in a car. Yes petrol is volatile, yes Lithium batteries are volatile and yes there was a manufacturing fault, but I believe there’s a design fault too and this should be addressed. I must re-iterate, when I say this is a design fault, I do not necessarily mean it’s a fault within a fully functional device; it’s simply that when the ideal circumstance hasn’t been met, the margin for error isn’t enough.
In my opinion, future phones should be built with a removable metal back. The back should house the battery cells and it should act as a form of heat sink–glass does the opposite. I don’t like the LG method of having a metal back and a separate battery–it’s bulky.
The software should report the average temperature of the device under a given load, to the manufacturer, and if the temperature is wildly off from other phones, the manufacturer should contact the customer.
I think we’ve started to notice these fires more recently because devices have became a lot more powerful and the sealing has meant greater heat buildup. USB 3.1 (I accept this doesn’t apply to Apple iPhone 7 phones) has only just started to get introduced into phones. I need this feature because I need a device that can clone SD cards, and USB 3.1 speeds are the best for this.
I think my ideal phone can still be made, so long as the glass back is removed, better methods for heat dissipation are implemented and Lithium Polymer batteries are exchanged for Lithium Phosphate batteries.