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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.
Different concept. Res ipsa loquitur means "the thing speaks for itself." It means no interpretation of a fact or piece of evidence is necessary. You're thinking of the concept of "strict product liability:" when a product causes damages, one does not need to prove actual negligence, just that the product caused the damage.
TANSTAAFL
Testing probably missed it because even with the thinner design it was a rare occurrence. Failures in 1 out of 200,000 phones is a big deal when you ship enough, but not so easily found in lab sampling. That said, the testing should mimic conditions beyond any expected in normal use and have a higher failure rate.
Air _is_ an insulator. Its the same idea as double pane windows.
Double glazed windows have a vacuum (or sometimes a noble gas) between the panes. If air gets in between the panes condensation starts to appear in cold weather. If that happens the window has to be replaced; they can't be repaired economically.
If God forks the Universe every time you roll a die, he'd better have a damned good memory.
These idiots have no idea what caused the fires. They haven't shown a single case where they can identify that the pressure on the battery causes thermal runaway. Remember that several phones failed while idle (not charging) and one failed while turned off (the guy on the plane). This "explanation" is just a couple of guys trying to Monday morning quarterback.
Is it just my observation, or are there way too many stupid people in the world?
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.
I thought that was in the Bible. Or maybe the Torah.
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.
None of what you said has ANYTHING to do with what I wrote, nor what was in the article. Did YOU read the article, or did you just jump straight to the TEAM link at the top to "play the man, not the ball"?
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.
Thanks for the link. Very helpful. If you read the article, you know that it says in the second paragraph (why don't I have to read beyond the first screen?):
We can use the link you provided to find out who "Sam and I" are, and with its helpful embedded linkedin links, find out what just how unqualified they are to comment on the Samsung phone:
Anna Shedletsky
Samuel Weiss
Oh dear. I certainly hope that those two experienced mechanical engineers spent more time examining the Note 7 problem than you spent attempting to trash their reputations. I guess Slashdot pest isn't a recognised profession either.
Yes, that's the translation of the latin, but it's use in law is correct as to "accident implies negligence". Please read beyond the first sentence in Wikipedia.
Double or triple pane windows usually have argon as the fill gas as both its higher molar mass and smaller molecular size than the diatomic major molecules in air increase its insulation ability because of reduced thermal conductivity. It's also naturally water free if provided from liquid argon which is generally available. FYI, the thermal conductivity of a gas is proportional to the square root of molar mass and inversely proportional to the square of the molecule's diameter. At least that's true for real gases at atmospheric pressure which behave nearly like ideal gases
In a time of universal deceit, telling the truth is a revolutionary act. George Orwell
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'