Wednesday, October 12, 2016

Why Does The Samsung Galaxy Note 7 Catch Fire?

The problems with Samsung Galaxy Note 7 phones, among the most feature-rich phones on the market, spontaneously catching fire have made a lot of news.  The problems first hit the news in August, not long after the phone first hit the market, and my reaction was that it must be some defective batteries or a problem with the charging circuit.   Samsung announced a global recall, so I figured they were on top of the issue.

The thing is, lithium ion batteries catching fire or exploding isn't that unusual.  Li-ion batteries have major advantages over other battery chemistries, so they're literally found in everything.  If it's a run of bad batteries, why aren't other company's phones catching fire?  That implies that it's not really a battery problem, it's a system problem.  Which is to say it's a Samsung problem.

The story is hard to pin down, so I've been bouncing back and forth between engineering sites like EE Times, business sites and those for the technically-inclined consumers, like C/NET.  Samsung, like most companies in this situation, is trying to balance being 100% open and responsive to customers, while not saying things that would discourage new customers and all the while realizing there's nothing they can do to please some customers.  At first, they thought the batteries were being pinched too hard in the slim case of the Note 7, as seen in the bottom video at the C/NET link, (originally posted in mid-September) but that cause seems to have lost some of the blamestorming it was subject to.

The company replaced the returned phones with units thought to be fixed in some way, but as of a couple of days ago, it has been reported that some of these supposedly known-safe units have already caught fire.  Today, the company warned users not to use any phones, even these replacements, and said they were shipping fire resistant glass shipping containers to return the phones.

Unfortunately, there is no clear answer I can give you as to why these particular phones are an issue.  It's being reported that the relevant Samsung engineers are virtually locked into the building until they solve this, and have been unable to reproduce the problem.  Each phone that catches fire tends to gather news coverage, but there really haven't been many.  C/NET says they can account for 112 phones catching fire.  That's less than .01 % of the phones sold.   

I've got to tell you this is a hard kind of problem to fix.  I can also guarantee that the first thing that's going to be found is actually not the cause but a dead end.  The problem is only going to happen once (after that, the phone is destroyed); they'll need to simultaneously test a lot of phones because it only happens to a small percentage of the product, and it doesn't happen immediately.  It's not new phones on their first charging cycle, and the phones were only out a few days before the first fires were reported, so it's not old, worn out batteries.  While one might expect the problem to show up during charging, there are several reports of the phone just catching fire while sitting on a table or desk or something.  I would say it's going to take time to get this resolved.  The best thing they could do would be to find a way to make an infrequent, rare, disastrous failure happen more often. 

EE Times relayed an interesting idea
Attributing an unnamed source who has spoken to Samsung chiefs, the Financial Times reported, “Problems with the phone appeared to have arisen from tweaks to the processor to speed up the rate at which the phone could be charged.”
Samsung's Note 7 comes in two versions, with one using Samsung's own Exynos 8893 processor and another based on Qualcomm’s Snapdragon 820 processor.
That makes me wonder if the way the code executes in those two processors isn't different somehow.  Since Samsung decided to cancel all production of the Note 7; if not killing off the latest model phone then putting it into a medically induced coma, that seems to indicate Samsung is relatively sure the problem isn't simply defective batteries.  It seems that the Korean giant realizes it must look elsewhere — other than batteries — to explain the alarming phenomenon of its smartphones bursting into flames.
The Samsung Galaxy Note 7 taken apart with the battery being lifted out of its normal position. From IFixit.


  1. Isn't there a line in the BenchTech's Prayer: "And save us Lord, from the intermittent fault, and the error hard to duplicate"

    1. For sure. Then there's the one that sunk into my brain so deep it's like tattooed on it: "Problems that go away by themselves come back by themselves."

  2. I'm almost clueless on this subject, but the notion of it being software programming for the way the battery gets charged (and perhaps the rate at which it self-discharges due to construction and chemistry) sounds like the most logical possibility.

    I do know that Samsung makes lithium ion batteries. I routinely use - and prefer - 18650 batteries made by Samsung for Xtar, and have been using them for over a year now. The only issue I have had with them happened recently, when one I was using in a flashlight was discharged so completely that none of a variety of chargers (Xtar, Nitecore, and Klarus) could recharge it. My fault, not the battery's, and no harm was done to any of the chargers or the LED flashlight it was in (why I hate side switches on my flashlights - they are so easy to unknowingly depress, even when in a belt holster or pouch, running your battery down and often heating it up to a very hight temperature - but below the temp at which paper or clothing will ignite).

  3. This suggests a companion question:

    Why do Amazon's various Kindle products not catch fire?


    1. Troll. Let Amazon do their own marketing. What an A$$.

  4. As Reg says "My fault, not the battery's" or, I suspect 'the phone's' is the true 'reason'.

    C/NET 'claims' to have identified 112, but as far as I'm aware it's still '7' out of all those millions. (And we all know just how honest, upright, incorruptible and ... impartial all those tech journalists are ... don't we? And please don't notice the 'donations', 'freebies', 'hiring practices' or 'junkets to exotic locales' of 'certain' companies, let alone the 'sensationalism' of every 'journalist' who reports on even the cookery/needlepoint/stamp-collecting situation).

    The relevant point is that Samsung engineers "have been unable to reproduce the problem" (no matter what they do to them even though their jobs and livelihoods depend on doing just that) and neither have any independent engineers or (desperately trying) tech journalists either.

    Me? I'm a curmudgeonly, paranoid cynic (I don't even believe me half the time) but ...

    As you say " ... why aren't other company's phones catching fire ..."? The point is, I guaran-damn-tee that they are ... but no-one is reporting them internationally, repeatedly in the headlines. Why, is the 'real' question, no? (Because, they are almost all likely to be due to the deliberate tampering or the idiot effect, and the 'journalists' want to 'protect' their favourite companies).

    I'd like to know if there are any 'congruencies' in the 'owners of those (7) 'spontaneously' combusting phones (in particular their 'allegiances', previous 'phone experiences/preferences', 'financial supporters' and ... IQ's). I mean, it couldn't be an industrial competitor doing this could it? They wouldn't do something like that, even if Apple was about to be wiped out by the universally judged 'ultimate phone' as against the i7's Meh! (or 'someone' shorting stock options ...'Soros' cough, cough). Hey, if nothing else, the numbers who fell for that 'charge your iPhone in the microwave' certainly exceeded 7 worldwide, didn't it? (And remember all those Volvo brake/accelerator 'mythical' linkages that caused scores of accidents ... but only to cars owned by incompetents, blithering idiots and/or 'fame seeking' individuals - and notice the frequency went up when those impartial journalists raised it as a tech doubt, instead of laughing at/feeling sorry for the idiots, with 'copycats'? Hmm, just like the, very similar, 'ecig batteries spontaneously combusting' scam, definitively proven to have been a 'put up job', no?)

    Nope, I'd truthfully still probably buy a Note 7 even now (if I didn't accidentally, it's a talent really, regularly drop phones off cliffs, in rivers, in beer glasses , and once ... OK possibly twice ... in a toilet, making a £600+ phone a stupid choice. And no, I neither buy Samsung or Apple products ... I'm cheap too!)

  5. My bet is industrial espionage. It is possible Samsung "rushed" the product to market and caused it's own problems but I doubt it. The product leapfrogging that goes on is short-lived and not worth the risk of taking a little additional time to get it right, especially when the market is not upgrading so much, i.e. slower sales overall.

    Each phone/user/circumstance then becomes a criminal type investigation. With all the pinging going on between cell towers even with phones are turned off, surely some activity trace could be run on what each phone was doing when said event occurred. Call me skeptical on this one.

  6. Able brought up something I hadn't considered - the idiocy of some owners who either do something stupid ("Hold my beer and watch this") or even intentionally test their own equipment to destruction. I swear that, other than getting a floor mat stuck under/around/jammed next to a pedal (actually happened to me once, in a guy's little Chevy sedan), there should have been _zero_ accidents from a gas pedal becoming stuck in those Toyota vehicles that killed or injured a few people. I'm sure a bunch of people jumped on the bandwagon in hopes of getting rich (only the lawyers succeed at that) from a class action suit.

    I tried various scenarios in my 2010 Toyota Tundra, and was always able to shift out of gear or shut the engine off (keeping the keys in the ignition so that I could steer the vehicle).

    I think that situation was contrived, and I wonder if that isn't the case here, with some fools playing around with their new Samsung toy, trying to see what they could do with - or TO - the device.

  7. To paraphrase, "Is Lithium, is not safe".

    or alternatively, "But why did the nitroglycerin explode??"

    It would be great to hear what actually happened. But, people want LONG runtimes. People want fast processors. People want small and light.

    That means super high energy density. Which is inherently dangerous.

    1. Is that a paraphrase of a movie quote? Cause I could swear I recognize it...from something...
      My wonky long-term memory aside *lol* you make an excellent point. Lots of energy in a teeny tiny usually a recipe for 1: a good time, or 2: very bad things.