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Engineers Explain Why the Galaxy Note 7 Caught Fire (digitaltrends.com)
Engineers with manufacturing technology company Instrumental tore apart a Galaxy Note 7 to try and figure out what may have caused some devices to overheat and explode, causing Samsung to recall and eventually cancel all Galaxy Note 7 devices. In their damning new report, the engineers discovered the root of the problem appears to be that the battery is too tightly packed inside the body of the Note 7. Digital Trends reports: They discovered the battery was so tightly packed inside the Galaxy Note 7's body that any pressure from battery expansion, or stress on the body itself, may squeeze together layers inside the battery that are never supposed to touch -- with explosive results. Batteries swell up under normal use, and we place stress on a phone's body by putting it our pocket and sitting down, or if it's dropped. Tolerances for battery expansion are built into a smartphone during design, and Instrumental notes Samsung used "a super-aggressive manufacturing process to maximize capacity." In other words, the Galaxy Note 7 was designed to be as thin and sleek as possible, while containing the maximum battery capacity for long use, thereby better competing against rival devices such as the iPhone 7 Plus and improving on previous Note models. The report speculates that any pressure placed on the battery in its confined space may have squeezed together positive and negative layers inside the cell itself, which were thinner than usual in the Note 7's battery already, causing them to touch, heat up, and eventually in some cases, catch fire. Delving deeper into the design, the engineers say the space above a battery inside a device needs a "ceiling" that equates to approximately 10 percent of the overall thickness. The Galaxy Note 7 should have had a 0.5mm ceiling; it had none.
This is bad. Very bad. If substantiated, the lawsuits against Samsung are going to be epic.
Why are there not physical insulators between the "risky" parts instead of merely air gaps? I'm not a psychical* engineer, so am I missing something? Do physical protection layers reduce cooling or something?
* I don't mean I'm virtual, but that I don't engineer physical stuff. Software.
Table-ized A.I.
Theory sounds plausible but doesn't carry much weight without experiments that demonstrate the internal battery components actually making contact as a result of the factors they describe.
....and this was not caught during testing because?
Correction, I meant "physical engineer". But if you were a psychical engineer, you'd know that already.
Table-ized A.I.
>"...what may have caused some devices to overheat and explode,..."
To my knowledge, NONE of them "exploded". Those that had actual problems had overheating which led to a fire. That is not an "explosion". That word was used by the media to stir up tons of inaccurate hype.
>"...causing them to touch, heat up, and eventually in some cases, catch fire."
Exactly.
If only Samsung had brought in Mr. Whipple to help educate the public.
What about stop making stuff super thin?
If this was the case then a slightly physically smaller battery would have solved the problem. They could have achieved this quite easily, even if it meant sacrificing capacity. And given they started by recalling the phones and replacing the batteries but there were still problems I would suggest they are wrong.
Hopefully this provides some motivation to stop equating thin with better.
Nah, who am I kidding, people are stupid.
As in most cases, going to extremes is rarely a good thing.
Not just minimum. Below minimum or none at all.
Intolerant tolerances will not be tolerated!
You have the right to remain sentient. If you give up the right to remain sentient, you will be elected to public office
So it's not a design flaw, merely people have been handling them wrong. Well, all's forgiven then, we have precedent that bad gripping by users is user fault, not company. Time to dismiss this as non-news.
If this was the case then a slightly physically smaller battery would have solved the problem. They could have achieved this quite easily, even if it meant sacrificing capacity. And given they started by recalling the phones and replacing the batteries but there were still problems I would suggest they are wrong.
Did you even look at the linked report? These engineers have the benefit of hindsight. They knew that the initial attempts to fix the problem failed; it's mentioned in the very first paragraph of the linked report. They said that sources from within Samsung had various theories as to the cause, so whatever fix that Samsung did it was the wrong theory. Just because Samsung got it wrong (twice) doesn't mean that these engineers were wrong.
Your post mirrors what was in the second paragraph of the report:
It's amazing that you can claim that what these engineers deduced wrong when you haven't even read even the first two paragraphs of what they thought. RTFA.
If they found the problem, it means that they can reproduce it. They were entirely unable to make their test unit fail due to the tight fit, nor were they able to observe that an increase in pressure of a phone in the off condition (under which at least one of the fires occurred in the v2 Note 7) *led to* a runaway thermal condition.
They're basically just speculating because they are looking for some clicks. This is about as conclusive proof as Trump has of 3 million illegals voting in California.
Is it just my observation, or are there way too many stupid people in the world?
You darn Social Tolerance Warriors! The Mobile Media has lied to you snowflakes! That's not fire, that's his hair.
Table-ized A.I.
Korean person: "No-no! Americans VERY heavy!"
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
Software "engineers" at best.
This is the company in question. https://www.instrumental.ai/te...
It's a small startup of 9 people with no history. None of the people are even listed as mechanical engineers. They're all software engineers (which isn't a recognized profession, by the way) and business people. Not a one among them has the authority to make any claims about the Note 7. None of them have the actual experience with the Note 7 to do so either - they had a single sample that they couldn't actually do anything with other than write the blog post and fish it out to tech sites for hits and to get their name out there.
People should bare in mind that this is at most an educated guess made by disassembling a single unit and speculating about limits of current tech battery design.
They were not hired by Samsung, they are not an official body of investigation, and they didn't have access to anything in the design in manufacturing process.
It's quite possible that they are right, but they are not explaining anything there, just speculating.
Now, it'd be extremely sad if the Note 7 was killed because of such a design oversight, because quite honestly, that's borderline amateurish. It could happen, as similar problems happen in most brands. Just that Samsung made the omission in the worst component possible.
We have examples of problems in antennas, cameras, lenses, connectors, shoddy speakers, crappy GPS chips, poor materials used in bits and pieces, among several other stuff... the difference is that if you have something wrong with battery, the consequences might not be only working poorly, ending up in glitches and whatnot. The consequence might be an explosion. Which is probably the worst thing hardware can do. :P
Anyways, the device is as dead as it can be. Which is plenty bad, because it'd probably be a best seller otherwise. Hopefully though, the lesson is learned by all manufacturers. It simply isn't worth sacrificing battery security to make the device thinner, or to shove extra mAh in there.
The worst part is that I can bet all you want that fans of the Note line would definitely not be bothered much with having a smaller battery or a slightly thicker phone. It's all about the stylus and screen size.
Back to the topic, I'd wait for further investigation for a final conclusion. Disassembling a single device and taking guesses is not that much better from theories that have been thrown around so far.
...Dilbert quote.
Much like testing for certain medical diseases, sometimes you can only determine a cause by exclusion.
When you eliminate the impossible, what remains are failures that can occur even with a battery that is neither charging nor discharging. The most likely causes, then, involve some form of physical damage.
LiPo packs change size during normal charging and discharging just a bit. That's why there are tolerances build into the design. With insufficient tolerances, bad things happen (TM), and even if the tolerances are sufficient to avoid self-puncturing at their maximum size, it is possible that flexing the case in just the right way while the pack is maximally swollen could still puncture the pack. So this is at least a plausible explanation, whereas most other theories aren't.
With that said, even if we assume that these folks are correct, it does not absolve other aspects of the design. Not all failures have only a single root cause. For example, IIRC, overcharging a LiPo pack can cause unusual levels of battery expansion from hydrogen buildup, which when combined with normal levels of flexing in a case that has insufficient tolerances, would result in the pack perforating and venting with flame.
Check out my sci-fi/humor trilogy at PatriotsBooks.
I don't understand the obsession with thinness.
Ever since my phone was less than 4cm thick I have been quite happy. What is this need to keeping shaving millimeters off?
If I had a DeLorean... I would probably only drive it from time to time.
Because unlike geeks who are often happy with purely functional devices, many consumers also want their phones to be sleek and stylish. And there are many, many more of them than there are of us. It's the same reason phones don't have SD cards or replaceable batteries anymore. We're no longer the target audience.
I've heard these people also tend to buy very expensive clothes that are no more functional than clothes that cost 1/10th the price. Crazy, huh?
Irony: Agile development has too much intertia to be abandoned now.
Phones have been sleek and stylish for years already.
Fashion isn't logical.
Irony: Agile development has too much intertia to be abandoned now.
On the other hand, you have EEs like me.
Engineering runs a spectrum. From near cookbook, long practiced, design processes owned by PEs to prototypes hacked up with three opamps, a FPGA, a breadboard and a coat hanger.
Design of consumer product batteries is 'near cookbook long practiced'.
Even I could do it. Samsung wouldn't have given me the authority to tell the PHB they _needed_ volume Y for X mWh. I guarantee there was an Engineer or ten that knew this was a bad idea, but couldn't penetrate the layers of management between him and the person dictating required features.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
They're all software engineers (which isn't a recognized profession, by the way)
You're not a real engineer unless you roll the petard up to the castle gate! These new-fangled train drivers aren't real engineers at all!
Socialism: a lie told by totalitarians and believed by fools.
Looks like I made a politically incorrect joke and got someone offended.
What has the world become...
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
It is, but not logical in that way. Fashion demonstrates that you can do something other people can't - whether it's spend more money, wear something that is inconvenient because you don't have to work, etc. What it's definitely not is about "getting something done efficiently". Quite the contrary, and hence the assumption of a lack of logic.
To paraphrase, a mobile can never be too expensive or too thin.
People perceive high-density products as high-quality, and low-density products as cheap plastic crap. Numerous products have included weights for this reason... take a look inside your mouse. People want their phones and laptops to be light so they don't have a brick in their pocket or backpack. Light * high density = low volume. They don't want to reduce the screen size, and bezels are already minimized, so the only option to reduce volume is to make it thin. Of course, once they make it thinner the advertising department will hype that feature, but the real driver is density.
Phones have been sleek and stylish for years already.
But this one is really hot off the shelves. An absolute blast to use.
Sounds disgustingly bulky to me. I'd rather burst into flames then have that gross nonsense packing my pocket. Ick!
What I don't get is that this is Samsung. This is a company that makes tanks and arguably produces some of the best conventional weaponry the world has seen.
They have engineers that know what they are doing. I know this sounds sarcastic, but Samsung has a very good rep in general. It makes me wonder how this happened, especially with a product that has so much visibility to the world. They would have been far better off making up the slight gap for battery tolerances by throwing in some expanded KNOX management features for the enterprise, or perhaps a model so people can have an unlocked bootloader to get more of the geek developers onboard.
And yet if you put an iPhone 4 next to a more modern phone, the iPhone 4 will look chunky and dated.
Only because you're the kind of person that believes the marketing hype about thinner == better.
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?