yashsingh1/xdaforums huggingface dataset:
[Note 7 Questions & Answers] CerveCesar:
READ CAREFULLY: Please read the entire article before making an un-informed jugdmement. I'm an electrical engineer from Michigan U. With almost 2 decades of experience on the field. And have put a lot of effort on displaying this information. This analisis is not to be used outside this forum and is only meant for conversational purposes. Feedback from other engineers is encouraged.

1.-Problem: Note 7 explodes or catches fire randomly.

2.-Conditions: New and Replacement units. With or without charger or cases attached.

3.-Comparison: Its predecessor the Note 5 has not reported fires. Its twin the S7 has not reported fires.

4.-Analisis based on Phone Design, Battery Supplier and Battery type.

5.-Pictures attached show the similarities on the Note 5 and 7. The most visible one is: SAME BATTERY SIZE, SAME LOCATION, HEAT SHIELDS AND BATTERY TYPE.

6.-The battery supplier is discarted, because there is no link on fires just limited to 1. And fires also present on replacement phones.

7.-Heat from chargers and Larger Screen are discarted, because Note 5 has the same screen size and type AMOLED. And fires occurred with or without the charger being plugged in.

8.-Fires occurred while phone IN USE or just put away into pocket while hot. Or charging and HOT.

9.-PICTURES: Show same battery size. However different battery chemical composition. Li-Po vs Li-Ion

10.- CONCLUSION: Samsung chose to have a less heat resistant Li-Ion battery with 15% more charge in the same battery space Vs the more expensive Li-Po battery. There is an interesting article from Android Authority here http://www.androidauthority.com/lithium-ion-vs-lithium-polymer-whats-the-difference-27608/ Ignition ocurs when the overheating of the charger+Screen heat and the lesser resistance to high temps of the Li-Ion are combined. Note 7 has larger screen than S7 therefore more heat accumulation. The thinner foil and other notes are not accurate, since the S7 has the same battery type from the same suppliers. Save and share this information, you will see Samsung show this study when things settle down and people have all new phones. Samsung is a larger multi-corporation than any other Company including APPLE and will recover its Customers.

For your time. I Thank you
[Note 7 Questions & Answers] CerveCesar:
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[Note 7 Questions & Answers] rcobourn:
Okay, I call BS before you even get to point 1. WTF is Michigan U? Nobody who went to the University of Michigan refers to it as Michigan U, because it is too easily confused with Michigan State University. The reverse is also true.

Meanwhile, your point 8 assumes facts not evidenced, rendering your argument invalid.
[Note 7 Questions & Answers] PhoenixJedi:
I disagree also. The very low number of bad phones can be explained by a pair of other things also. USB-C has a KNOWN issue. Faulty non-certified cables have been known to damage devices. The phone sold SO MANY units that it could be very explainable that all of those people who had exploding units used a faulty USB-C cable they got from a cheap source.
[Note 7 Questions & Answers] richie_b:
so y didnt sammy just replace the li-ion with a smaller 3000 mah li-po and call it a day and let everyone enjoy the phone
[Note 7 Questions & Answers] CerveCesar:
The problem with the response. Is that some devices burned while inside the owners pocket. Yes, the USB type C has issues, but it does not apply directly to these fires. This is why I did not take it into consideration ?Thanks for the feedback
[Note 7 Questions & Answers] PhoenixJedi:
You could be right. However, it could have burned while in the owners pocket AFTER a cable had already damaged the power system.
[Note 7 Questions & Answers] CerveCesar:
I don't think your ignorant comment deserves an answer
[Note 7 Questions & Answers] QuickSh0t:
Point of note / Hypothesis

I have a Note 7 I received it 2 days before the first recall. I had it plugged in initially to charge and I noted the high heat on the lower portion of the phone pre recall. I turned off fast charging and although I never leave it alone when charging just for security and peace of mind there has no longer been any notable heat since I turned off the fast charge. I have reported these results to Samsung but those I have spoken to are idiots that don't understand I'm trying to help them and refer me to turn in my phone and exchange it for another device type ..... Not liking my options ..

I believe the issue is that the battery itself cannot handle the 2.1 amp charge the usb type C allows for with fast change enabled. Without fast charge on you get the charge performance of a usb 2.0 charger it takes longer but it works just fine. I have had no issues since . Now that puts the blame on poorly utilized batteries of charge controllers in the phone itself.

I have heard some rumors about a battery switchout option not via Samsung that can be done however I'm awaiting details on it.
[Note 7 Questions & Answers] CerveCesar:
Good point, The 2.1 amp charger changes from about 5volts regular charge to 12volts for fast charge. I think this is the problem you found with the Overheating Issue ?
[Note 7 Questions & Answers] nomailx:
The problem was sooo simple, and all the engineers in Samsung couldn't figure that out. Instead they'd rather risk a complete decimation of their company by refurbishing the exact same batteries to the replacement models?

Are you serious right now?
[Note 7 Questions & Answers] richie_b:
agreed ....just change the darn battery type to Li-Pol or drop to 3000mah ...it got quick charge to compensate
[Note 7 Questions & Answers] CerveCesar:
I'm not exactly sure what you mean.

However, I feel the engineers at Samsung rushed to blame 1 supplier after the first 23 or so fires and came up with a bad call. It happens, we are human. As for my study, I really believe that Samsung will announce this at the right time. Remember: Engineers will not make an official statement at any company. That is the responsibility of the management. They have to take many things into consideration; Including the information provided in a lawsuit by an attorney. So the less people know the better it is for them. Do you agree?
[Note 7 Questions & Answers] rcobourn:
You got the first part of that right.
[Note 7 Questions & Answers] QuickSh0t:
Yep S7 Edge and S7 not going boom , difference those don't have USB type C Charging therefore less voltage even with a quick charge operation on the device.

Of course one must consider differences in battery manufacturer , composition and amperage limits in input as well... edited because it would be ignorant to leave it out :P
[Note 7 Questions & Answers] CerveCesar:
Not 100% the S7 limits at 3000mAh the Note 7 3500mAh same chemical type?
[Note 7 Questions & Answers] Belimawr:
has been a couple of reports of S7's going pop in the UK recently. obviously not on the scale of the note in the US but there has been a couple, the sad fact is some batteries will always fail. to me it is more likely this recall is just because people have lost confidence in the device due to a couple failing since the first recall. would be interesting to be in samsung to see what is actually going on behind closed doors.
[Note 7 Questions & Answers] aznmode:
I don't know if this has to do with using type C or the percentage of failure would be higher. I'm sure almost every average user was using the default charger and cable and left it default to fast charge.
[Note 7 Questions & Answers] sonhy:
some good points and some bad points for a good thunking session. nice to see some reasonable negative discussion :)

I believe its the usb-C port! but I also believe in UFOs :p

but just remember not to rely on second hand information and those that cannot be confirmed, like claims of phones firing up in pockets without warming and were used properly; internet reports of figures; but yet ignore the overall stats. At this point id say samy would be the only one with actual real evidence and data.

millions of units were sold and used, probably all heavily used when they first got them, heated up the phones and fast charged while hot (i always do when I get a new a phone) , yet a very very very small number have caught on fire. that makes it tough for me to believe it's the battery & heat causing the fires.
[Note 7 Questions & Answers] DeMi-GoD:
If this was the problem, wouldn't you think more would have caught fire? 96 out of 1.9 million in the US...

---------- Post added at 12:34 AM ---------- Previous post was at 12:33 AM ----------

Btw, I always fast charge my note 7, many times while I'm still using it and most of the time it doesn't get warm in the slightest. It's by far the coolest running phone I've ever had.
[Note 7 Questions & Answers] CerveCesar:
Is that the Original or the replacement model?
[Note 7 Questions & Answers] DeMi-GoD:
I have the replacement model.
[Note 7 Questions & Answers] Claudio Santos:
Seriously nobody have thought it to be a software malfunction ? ..
[Note 7 Questions & Answers] CerveCesar:
Maybe you have reduced the factory screen brightness and other sources of heat that affected those who's phone caught fire with during hot August. When it came out
[Note 7 Questions & Answers] DeMi-GoD:
Maybe tonight I'll fast charge my phone with max brightness while gaming, sitting next to the fireplace, and see if anything happens.
[Note 7 Questions & Answers] Aimara:
ermm charging next to a fireplace is not a good idea
[Note 7 Questions & Answers] DeMi-GoD:
It's actually just an electric heater that looks like a fireplace.
[Note 7 Questions & Answers] Aimara:
one youtuber did test it , over a high wattage lamp , it did does a thermal runaway
[Note 7 Questions & Answers] CerveCesar:
Excellent! That was my point. We all know the battery will ignite when overheated. The reason was not known or it was not published by Samsung. Read my study to find out the most likely cause of ignition
[Note 7 Questions & Answers] svache:
I don't know, even then I still don't think all phones are affected. I live in Hawaii, it's fairly hot still, I'm not in AC either, at times I run games that make the Note 4 turn pretty hot while charging, my Note 7 doesn't get hot at all, not even while fast charging. Like Demi-God said, it's the coolest phone by far. The previous (original) Note 7 I owned, however, did get super hot through wireless charging (regular charging not so much).
[Note 7 Questions & Answers] motfis:
How about s7edge? It is also Li-ion with 3600 mAh
[Note 7 Questions & Answers] nomailx:
Ok, let me give you the benefit of the doubt. and raise it with an even more insane theory.

Is it possible that they genuinely believed that China's Note 7 were safe, just based on the news, and decided to not even try to Solve the problem but instead put the exact same battery manufactured for the Chinese version, JUST Based on the news...??

Seems legit if you take into consideration how fast they responded with the recall, green battery icon design, immediate production of the "so called fixed" handsets, etc...
[Note 7 Questions & Answers] assass1n_02:
I have a replacement Note 7 unit and mine gets pretty warm, depending on what I do. But I do usually have my brightness pretty high. Just wondering if any of you guys use a battery temp app to check? Mine gets as high as 37.5 Celsius - 99.5 Fahrenheit especially when I'm fast charging and using the phone. Is that within normal temperature ranges?
[Note 7 Questions & Answers] Aimara:
hmmm 37 is ok
[Note 7 Questions & Answers] BozQ:
Let's not rule out the possibility of a faulty firmware/software pushing the battery.

Also, I believe the US is using different chargers from the rest of the world, yes?
[Note 7 Questions & Answers] assass1n_02:
Thats good to hear. My S6 edge would get way hotter than my Note 7 but given the circumstances I'm just keeping an eye out on my Note 7.
[Note 7 Questions & Answers] taz1458:
Considering the highest mine has gotten on fast charge while messing with it is 95, thing is yet to get hot. Like I said, I had it in the sauna before and it's still fine. Lol
[Note 7 Questions & Answers] richie_b:
+1 fast charge mine too and it just got slightly warm my nexus 5 gets so much hotter on slow charge, its just confusion ..
[Note 7 Questions & Answers] whoofit:
I'll just leave this here. https://www.youtube.com/watch?v=QDCurir7VQk
[Note 7 Questions & Answers] Boy Bisaya:
I like this thread! Really. Going forensic for what is now declared an extinct Note7. Designers sometimes call this post-mortem analysis. Thanks by the way, CerveCesar for starting the thread.

Probably my first question would be. Anybody's got a copy of the Note7 mainboard schematic? It's stupid to ask but worth a try. If someone has a copy, please share. :p

I've been trying to link the incidents to the electrical/PCB/Mechanical architecture and structure of Note7. Most of my references as to the industrial design (call it mechanical structure in layman term) of Note7 is coming from Note7 teardown from iFixit.

Let's start with the electronics. For those who are already familiar about this, please bare with me. When facing the Note7 screen, the mainboard runs from upper left area of the device just above the Vol+ control across rear camera to power button and down to somewhere in the middle of (inserted) S-pen. The lower left up area up to just below the rear camera is the battery. Now, battery from off-center towards the left. Electronics and S-pen towards the right. Now go check the photos of the charred Note7 posted in the net. Charring from most of the photos are at the left area but still, there are others that show charring towards the right.

Let's identify the heat generators. Major components that generate heat when operational are all placed on the right side area of device between the S-Pen and battery. We can find there the processor+RAM (stacked for SD variant - we call it Package on Package in Semicon packaging) and the power management IC (PMIC). Note7 and S7 Edge shares almost the same placement. I mean component location.

By comparing major components, I notice that S7 Edge has three PMIC (two from Qualcomm and one from Maxim) while Note7 only has two (both from Qualcomm). Probably iFixit just missed to mention Maxim. That's the reason why I asked for a schematic earlier. The one from Maxim is a voltage regulator, battery charger and power path controller in one. I would presume that the PMIC from Qualcomm is responsible for the component voltages supplied to processor, memory, etc. I cant find the datasheet of that right now. The absence of Maxim PMC may mean additional workload to Qualcomm PMIC which then leads to an even higher temperature inside. I wasn't able to research temperature performance between Note7 and S7 but I think it would be irrelevant as the mechanical structures are different.

Wrapping the discussion up for now, you can see in the attachment the photo I've taken from iFixit. Tell me whether that is a glue or an irregular metal edge. If glue then its fine. Irregular metal edge however would then mean a risk. Fast charging + heat + external pressure (Note7 inside pocket) could compromise the integrity of the batterypack. Fast charging could lead to overcharge (missing Maxim ???) which leads to gassing. Gas bloats the battery packaging. Bloated pack + irregular metal edge will lead to disaster.

Again, let's not conclude just from one photo alone. I am just presenting where the failures could probably originate.

EDIT: Credit goes to iFixit for the photo. :o
[Note 7 Questions & Answers] mav42:
From a cold boot or full shut down restart mine got to 75-80c then cooled down to 27-33c when running Antutu it got up to 80c when running CPU tests (around 50-60c for graphic) running normal apps like bubble witch 2, Vegas slots etc 45-50c was the norm......used app CPU temperature which has a temp overlay for testing
[Note 7 Questions & Answers] juliend:
There was no time when either of my note 7s felt hot while charging, fast charging, gaming while fast charging, nothing. What's to say those folks who's phones did melt didn't ever have them feel hot until they self destructed?
[Note 7 Questions & Answers] xda2jojo:
I am using my Note 7 daily as a Dashcam attached to a Car Windshield Mount with Wireless Charger .

I always got this:
[Note 7 Questions & Answers] br0adband:
~`

~121F on the battery temp, geez man, you're just itching to end up killing the device yourself. The usage, the fact that it's probably in direct sunlight at various points in time, wow. My battery temp at this moment is 97F and I just ran a full Antutu benchmark to see how high it might push the temp on my Galaxy S7 Active.

If it keeps working and never does have issues, congrats, but that kind of treatment is sure to cause a problem sooner or later - might not have anything to do with the reasons the device is being recalled but, even so that kind of environment is certainly not conducive to the device lasting a long time. :(

EDIT:

Did some quick research and typically the "safe range" for temps for Li-Ion batteries (which the Note 7 and my GS7 Active have since Samsung didn't use Li-Po unfortunately) is:

That isn't a hard thing overall it's just a recommendation based on usage and the technology but even so, 121F, ouch, double ouch. :D
[Note 7 Questions & Answers] CerveCesar:
Good one! However, there is not enough information on the amount of units sold and I assume if 1 caught fire, it would equal the Note 7 in sales percentage
[Note 7 Questions & Answers] CerveCesar:
I don't get your point?
[Note 7 Questions & Answers] CerveCesar:
Yes! I get mine up to 48C while driving in the sun with no a/c, wireless charging and the waze running. Original white icon. However I quickly used the low heat methods and charging to 80% to avoid overcharging the Li-Ion battery

I must add that before the update wireless charging would go 3 minutes uninterrupted. After the update its 30 seconds.
[Note 7 Questions & Answers] CerveCesar:
Hi there Bisaya. Interesting questions, I also looked to see if there was any sources of intense heat that may accelerate the ignition process and came up empty. There is a heat shield between the N7 batt and the screen. Not present on the N5. Also there is no direct connect between the Snapdragon (US) and the faster/Hotter Exynos (Korea) Since fire was present on both and US/Korea use the 120Volt Outlets. China uses the 220V. The Snapdragon is also currently used on the S7 and no problems are shown. The aluminum frame could in fact contribute to puncturing the battery if this one inflates during the normal heating process, Yes that's a great observation that I did not consider. But the N5 also has the same opening in their frame. The body of the N7 is narrower and more shallow Vs the N5. Leaving less room to heat and expand ?
[Note 7 Questions & Answers] Belimawr:
there has been some recently.....

https://www.thesun.co.uk/news/1781420/why-are-samsung-galaxy-s7-edge-phones-exploding/
[Note 7 Questions & Answers] wildwong:
It's still hard to explain why only like 100 units caught fire in a million batch...
[Note 7 Questions & Answers] br0adband:
It's more than 100 worldwide (96 reports in the US so far), why not do some research into the matter and learn some of the facts instead of just repeating what most other ignorant folks do?

And there's no guarantee that a defect will always appear and make itself known in a given situation with given hardware of any kind: car recalls typically happen when a part goes bad on just a handful of devices because public safety is more important and that's the situation here as well.

Since they can't seem to identify exactly what's causing the problem - they thought they had a good idea with the 1st recall (the battery) but that turned out to not be the issue since the newer models apparently exhibit the issue as well. It's more than likely the battery construction itself in this situation and the lack of space/incredibly tight tolerances inside the Note 7 and the revamped internal design (even the glass is different now).

We may never know precisely why this is happening and that's fine - all that needs to be known at this point is that the Note 7 is effectively dead and should be returned. If you keep one you do so at your own risk and potential liability for any damage or injuries that might happen because of continuing to own/use one.

Is that so hard to grasp for so many people? :confused:
[Note 7 Questions & Answers] lawrence750:
one thing that has crossed my mind, and so far I haven't seen mentioned..

this talk about the plates in the battery being compressed together, in relation to the steeper sides of the note 7 compared to s7 etc.

what if:

Think about bendgate. What if, this is happening to a degree(note I'm not saying the phones are being bent, just sat on or similar), which then causes the short circuit (eventually)? It's not gonna happen *that* much, because let's be honest, most people aren't stupid enough to sit on their phone.

It could have been damaged slightly, and then when heated up later by charging, an expansion occurred, thereby creating a short circuit and resulting fire.

Look back at the HTC One X - there was this issue where over time, slight pressures on the casing of the handset would eventually cause the antenna connection for WiFi/Bluetooth to compress and because of the design of the antenna connectors to the mainboard, they would get worse and worse over time (and if i recall correctly, the phone getting hot would also exacerbate the problem)

Think of it all.. I do wonder...
[Note 7 Questions & Answers] wildwong:
No, what I meant was, if it's all the "more likely" causes why it's so hard to duplicate the explosion? Like if it's a USB Type-C/Fast Charging problems, then it'd be affect much more than "more than 100 worldwide". I didn't say I will keep it and actually I got a refund already.
[Note 7 Questions & Answers] Ryland Johnson:
BINGO.

Though I understand threads like this, its a forum, what amazes me is the amount of speculation. Samsung electronics employs hundreds of highly trained highly qualified engineers from all over the world and even they, at present,

apparently

cannot replicate the problem yet here we are stuck in a thread debating the possible causes?

As you wrote this is also futile as in the USA the recall is now official. In Europe the recall is not yet official. If it becomes official here that would mean to own, sell or stock the device would be

illegal

. I have no idea what an 'official recall' means legally in the USA though?

What I do know is that keeping this device is selfish. We don't live in isolation so what we do will affect others. We are debating here a mobile phone! Is that really worth the risk? Mark my words some one in the USA is going to end up in serious trouble by keeping this device. Oddly enough that person or persons will then complain about being taken to court? If owners in the USA fail to cooperate then big brother will step in and block the phone.

With certainty Samsung will not be offering any further updates etc nor future warranty on this recalled device.

Those who are fighting to keep them are going to end up with a dangerous door stop of zero value. Bloody crazy behaviour.

With great regret the Note 7 is in the past. Get your money back and move on looking forward to March when the next flagship arrives. Keep people safe.

Ryland
[Note 7 Questions & Answers] XanaviGTR:
Just for curiousity.. after they ( Samsung) asked users to return the phone, till now, phone catching fire news seems to cease with it? Not that i hope for one... but hmmm....
[Note 7 Questions & Answers] SeraphSephiroth:
Okay lets look at statistics. It's about 0.1% of shipped units that have exploded. That's about the standard failure rate for any new product. The issue is, I think, that usually the failures in electronics and other new devices aren't so explosive. Honestly, a failure rate of even 1000 out of several million units sold worldwide wouldn't raise this much of a flag if the results weren't so explosive. I plan to keep my Note 7 as the statistics stand in my favour.