What makes a phone battery explode?

Exploding battery talk is something you can't escape right now, thanks to a problem with the Samsung Galaxy Note 7. It's good discussion to have: the more people talk about it, the less likely it is for a child to get hurt from a battery failure. As much as we hate to see a product we like experience safety issues, we hate seeing people get hurt far more.

But the Note 7 isn't the first phone to ever go through battery problems, and it won't be the last. There will always be isolated incidents of batteries failing as long as we use phones with lithium-ion cells, and the Note 7 isn't the first phone whose battery needed a widespread recall because something is wrong under the hood — as long-time Nokia fans know too well. It happens. It's never a good thing, but it's a thing. Let's talk about why it can happen.

How your phone battery works

Samsung battery

The first thing we need to understand is how exactly the lithium-ion battery in your phone works. The name gives us a hint — electricity is carried from one electrode to another using charged lithium ions.

Electricity meets chemistry meets metallurgy — that's what makes a battery possible.

Lithium-ion batteries store, transfer and release energy because of natural chemical reactions. The battery has two electrodes — an anode and a cathode. The cathode is connected to the positive (+) connection on the battery and holds positively charged ions, and the anode is connected to the negative (-) connection and holds (you guessed it) negatively charged ions.

Between the two electrodes is what's called an electrolyte. The electrolyte in a lithium battery is (usually) an organic solvent paste that has a very large number of metallic salts (in most cases, that metal is lithium) as part of its makeup. This makes it electrically conductive — electricity can pass through it. The anode and the cathode are in the electrolyte and separated by a physical barrier so they can't touch.

When you discharge the battery (when you're using your phone and not charging it) the cathode pushes its positively charged ions away and the negatively charged anode attracts them. Electricity flows out from the anode, through your device, then back to the cathode. Yes, electricity travels through a loop and isn't "used up" by the thing being powered. When you charge your phone, the reverse happens and ions travel from the cathode through the electrolyte to the anode.

Lithium is the perfect element for rechargeable batteries: It's lightweight, easy to recharge and holds a charge for a long time.

When these ions come in contact with the charged atoms in an electrode, an electrochemical reaction called oxidation-reduction (redox) frees the charged electrons to travel out through the battery contacts, which are connected to the electrodes. This continues to charge the lithium ions in the electrolyte until there aren't enough left that can hold a positive charge that's strong enough to move through the electrolyte paste, and your battery will no longer charge.

Lithium is the lightest metal — number three on the periodic table. It's also very excitable, making it easy to create a powerful chemical reaction. This makes it a near-perfect metal to use in a portable rechargeable battery. It's lightweight, easy to recharge and continues to hold a charge for a long time.

What can make a battery explode?

Samsung battery

For starters, let's define what explode means in this case. The electrolyte paste inside a lithium-ion battery is extremely volatile. It can (and will) react violently to other metals, and has a very low (180-degrees Celsius) melting point. Inside a sealed battery casing, the pressure generated can build up until the casing is ruptured, then rapidly escape. The pressure carries out extremely hot electrolyte fluids which can cause other things to catch fire. Some lithium batteries are vented with an escape hole so they won't rupture under pressure. When the battery casing ruptures and superheated liquid filled with melted metals is expelled under pressure, it causes an explosion.

There are two easy ways to make a lithium battery explode — heat, and physical damage. Let's look at both.

Overheating and overcharging

This is the most common reason a battery fails. Something goes wrong in the charging circuit and the input power continues to drive the chemical reaction. One place in the battery will eventually get too hot and, since it is still being charged, it can't cool down, causing what's known as thermal runaway.

In this case, the hot portion starts to generate its own heat, which makes other areas in the electrolyte overheat, and they cause more spots in the battery to overheat. The heat expands the electrolyte and creates steam, building pressure until the battery casing splits and forces out all the pressure and some very hot, very sticky (and very flammable once exposed to the air) gooey liquid.

A thermal runaway can happen fast enough that you don't even feel the heat before the battery fails.

When such a rupture happens, it can cause physical damage to the things that are close to it — when holding a phone, circuit boards and glass or plastic. These materials can also catch fire from the heat, which in turn makes the escaped electrolyte ignite and act like napalm — fire that sticks to things until it burns through them or burns itself out.

The thermal runaway process can happen very quickly, and things can go from "normal" to catastrophic failure inside the battery before the heat is even transferred through your phone to your hands. Thankfully, the hundreds of millions of lithium batteries produced every year have an extremely low (almost statistically insignificant) failure rate due to thermal runaway, partially because of safety measures (subscription required) like non-flammable additives to the electrolyte and coatings.

When your phone tells you that it's too hot and won't charge or run at full speed, it needs to cool down so thermal runaway doesn't happen. Listen to the little pop-up and let it cool.

Mechanical damage

Lithium batteries are designed to be lightweight, deliver high output, and be easy to charge. This means that the outside shell and the barrier(s) separating the electrodes are very thin and light, with most of the weight coming from the parts that can actually power your phone.

Because the partitions and case are thin, they're fairly easy to puncture or tear. If the structure of the battery itself is damaged in a way that makes the electrodes touch, a short circuit will happen. The instant electrical discharge is explosive, which can (and will) heat the electrolyte and create pressure to push it out through any ruptures in the battery case. It's hot, it's flammable and it's in contact with a spark. That's a recipe for disaster.

It's hot, it's flammable and it's in contact with a spark. That's a recipe for disaster.

A thin casing is also a safety precaution, though it sounds crazy. Thinner metal is easier to rupture, so less pressure can generate inside a sealed case — essentially creating a vent hole. Pushing out flammable hot liquid under pressure isn't a good thing. Letting more pressure build until it ruptures a thicker case is worse.

Other metals coming in contact with the electrolyte paste can also create a spark that leads to failure. I'll let you search YouTube yourself to see incredibly silly people puncturing phone batteries to make them explode. The reaction to foreign metal does the same thing as a short, but on a smaller scale.

What about the Note 7?

Note 7

Image credit reddit user crushader

For starters, nobody but Samsung knows why batteries in some Note 7s have exploded. They sent out a short statement (opens in new tab) through their U.K, division that doesn't really make sense. The wording "the anode-to-cathode came into contact" sounds like they are describing a short, but as written it means nothing. I won't try to interpret something that isn't clear in a case like this. But I can say what I think as an armchair quarterback who has never seen a Note 7 explode or inspected one that has exploded on his own, a situation where the anode shorts to the cathode does make the most sense.

Because people have reported the Note 7 battery failing without it being plugged in and large portions of the phones we see in pictures are not burned, I'm going to assume that it's not a thermal runaway situation, even though Health Canada expicitly says the lone failure in Canada was from overheating,

Anyone outside of Samsung can only make an educated guess about what's happening.

A thermal runaway situation isn't as "instant" as a direct short, and the excited electrolyte solution would take a longer time to exit a burst battery then continue after an explosion ruptured the case. More than just a portion of the phone would be burned, as well as other objects in the immediate area. A heat explosion also would cause the battery to swell before the flexible casing would rupture, and with no room for expansion, the swollen battery would crack the outer shell of the phone. There are videos on YouTube that show how this happens, and here is a great (albeit old) example of someone circumventing the safety measures to make it happen. Someone would have mentioned the phone swelling up before it blew, I would think.

I also don't think any foreign objects or manufacturing leftovers are coming in contact with the electrolyte. I know this is a popular theory, but if a batch of batteries (we're not even sure how big a "batch" is in this case) all have small particles in the electrolyte, we'd be seeing a lot more Note 7s exploding.

A short inside the battery or in the charging circuit combined with an electrolyte that's been treated with non-flammable additives seems more likely to me. A quick explosion that releases a small amount of pressure and fluid at once could quickly burn itself out if nothing were in contact with the phone. When the phone is in contact with something that is flammable, say the seat of a Jeep, it could cause a fire.

Of course, there could be plenty of other factors that we don't know about. The manufacturing process used to create a lithium-ion battery for a phone makes them very safe to use. But there is also a lot that could go wrong.

A preliminary report by Samsung to Korean regulators blamed a production error that brought plates within the battery into contact, triggering "excessive heat." The report noted that more analysis was needed to pinpoint the exact cause.

Initial conclusions indicate an error in production that placed pressure on plates contained within battery cells. That in turn brought negative and positive poles into contact, triggering excessive heat. Samsung however stressed that it needed to carry out a more thorough analysis to determine "the exact cause" of battery damage.

What we do know about the Note 7 and its battery

Samsung Note 7

We have no idea exactly what's happening with the Note 7 nor does anyone outside of Samsung. But we can make an educated guess based on the little evidence we're privy to. And in the end, it doesn't matter. The Note 7 has been determined by Samsung to be faulty and we're all supposed to stop using them and return them. A replacement without the issue is in production and already on its way to the sales channel. We don't need to know why it explodes to know that we should get rid of it.

Samsung recommends you power down your Note 7 and stop using it.

Samsung and your carrier (or other retailers like Target or Best Buy) have policies and methods in place that allow you to return your Note 7 without losing any money. Some offer loaner devices you can return when corrected Note 7 phones make their way onto the shelves, while others simply offer an outright refund. Either option is better than risking your hand or your face if the battery does fail.

We've compiled everything you need to know in one place, and we're also happy to answer any questions we can in the comments or on social media.

Samsung Galaxy Note 7 recall: Everything you need to know

Jerry Hildenbrand
Senior Editor — Google Ecosystem

Jerry is an amateur woodworker and struggling shade tree mechanic. There's nothing he can't take apart, but many things he can't reassemble. You'll find him writing and speaking his loud opinion on Android Central and occasionally on Twitter.

  • This is just all around bad for Samsung and not limited to the Note 7 but the trust of its future phone. Obviously this is an isolated issue with one device and doubt it will be an issue moving forward, but the damage has been done. The Airbag recall, tire blowout, etc. Companies will always survive, but it definitely tarnished the trust of consumers. I'd definitely will continue to buy Samsung because they are one of the few companies that actually admitted an issue and tried to resolve it quickly instead of saying "you're holding it wrong"
  • Did you read this? It's not an isolated incident to one device. That kid had another model explode. An iPhone caught fire in mid-flight a short time ago and another that pops to mind is an iPhone 5C that exploded in the back pocket of a 12 year old while walking to school. I've seen stories of Nexus 7's, 6P's another lithium ion having devices going pop. It's a risk we take. The Note 7 has a defect they identified hence the recall but it's by no means isolated.
  • The air bag fiasco is a little different in that the manufacturer tried a simpler and cheaper way of manufacturing the inflator, and, even though test have shown that the new process wasn't perfect and could lead to this problem, they chose to stay their course.
  • "When your phone tells you that it's too hot and won't charge or run at full speed, it needs to cool down so thermal runaway doesn't happen. Listen to the little pop-up and let it cool." What if that pop up comes up while you're sleeping or away from your phone (in the other room)? Ever since I heard about the Note 7 battery stuff, I found this app that may warn me a little better than the phone's pop up. Honestly, I think I'm going to keep this app on any phone I own, it's always good practice to be aware of the battery's temp/health, no matter the brand or manufacturer. https://www.androidcentral.com/e?link=https2F2F...
  • I wouldn't charge it at night for sure. Mine is 100% before I go to bed and when I wake up 6+ hours later, it is usually around 90%.
  • I do the same thing -- and not because I was worried about any of my phones blowing up (maybe I should be). I just do it that way. I hate having things plugged in after they're fully charged. Overnight charging seems to be a waste to me.
  • That statement in the article isn't addressed to the folks who recieve it at night, it is addressed to the folk who recieve it while on their phone and choose to ignore it. As for what if you get it at night? There is no way that it would matter because you wouldn't see it, thus rendering the message (IN THAT CASE) useless. Though, it was a widespread thing a few years back when that notification was being ignored. People asked what to do when they saw it and the general answer was "ignore it" - which was as wrong now as it was then.
  • Just samsung is a big brand there is lot of light on it...
    But even other phone likes of apple ,redmi and all have exploded...while samsung needs to get hight quality control back as their main flagship has manufacturing defects...
    Once safe units arrive all will go back to normal...luckily in india there delayed the launch...
    Thou many people in the forums have switched to S7 Edge and are very happy...soo lets see once new units of note 7 arrive samsung needs to create a buzz again for Note 7
  • This is why I like removable batteries !!!! My Note 4 battery ballooned to about 1/3 thickness more, bulging the back door off a bit, while camping in hot weather. Luckily, I was able to switch to one of my back-ups I kept in my packs.
  • Yep, the recall would have been super cheap compared to this. They could have sent a new battery and been done with it. It also would have been much less of an inconvenience for people.
  • Removable batteries can pose another issue though. If the consumer buys a low grade cheap battery for replacement and those start blowing up the focus would still be on Samsung. Nobody is going to focus on XYZ Battery Co. as the culprit.
    Damned if you do...
  • @cmdacos : I think most pre-Note 7 battery problems were caused by cheap knock-off batteries. A couple of my co-workers at my last job in fact destroyed their smartphones that way and blamed Samsung -- and Samsung had to replace the damaged units.
  • amen!
  • the s4 had a fault battery batch too but you could just contact samsung and they would send out a new battery.
  • Absolutely! I love my note 4 and will not upgrade to a newer note until they go back to removable batteries! Also the note 4 is the last one I can control TV's, blue ray players etc with because the new notes lose the IR sensor! My note 4 for the first time the other week wouldn't allow my video camera to run when I was taking pictures of the air show because it was so hot out my phone was literally burning my hand. I kept it out of the sun to cool down, changed the battery (no bulge just hot) and it was fine to take video in a few minutes. Note 4 still the best. I would buy another note 4 if this one broke.
  • Note 4 is def the best that Samsung has done *to me*. I prefer function over form any day. This phone has been through the heck and back and all I had to do thus far is dispose of one battery, no complaints from me. I abuse my phones, no white glove treatment from me and no inch thick brick-like armor cases lol. It has even handled the occasional rain or being splashed by the kids. Countless drops and only a few scratches so far.. Although I am a Sammy fan, I am eying the LG V20 to replace ALL my phones next.
  • Same here! I actually did pick up another new Note 4 recently as insurance (still have my original release one as a backup) since it's such a great device yet and ticks off all the hardware features I value! New one is now rooted and tweaked (will do the same to the back up as well). Along with a total of 6 batteries think I can comfortably wait to see what Samsung does with the Note line the next year or two. :)
  • For some reasons Samsung like to produce multiple version of phones in particular period of time, and not to Note series. It would be nice if they can produce 2 versions of Note, the first one is 'premium' version, with edge screen, glass backs or other premium materials with built-in batteries, thin and fancy design, etc. Basically what the iPhone crowds and people who use their phones as fashion materials. Or basically what changed to Note 5 from Note 4, and carried over to Note 7 now. And the second one would be focused on usability. Can just based on Note 4 design. Just put in latest processor, latest screen as many RAMs as presently expected by market, adding back removable batteries, plastic/rubbery back ( more durable, easier to grip..no phone should need case to be usable), front stereo speakers, and maybe a bit of water resistances just like Galaxy S5. Maybe IR blaster as well. Both camps are happy. Samsung wins.
  • @Pyro The cost to produce multiple versions is more of a cost savings and steam line decision. I do agree with you...they should make a "premium" version of the flagship product and then a more basic version (like you said, removable battery) with all the bells and whistles but just not as "sexy". They probably worry that the "generic" looking one will sell better and then they won't be considered a "premium" mfg.
  • Well, only thing to do is vote with your wallet and buy LG.
  • @fuzzylumpkin
    LG V20 for the win!
  • I have noticed the past couple of nights that my note 7 will have a blinking red led light when I plug it in, instead of the solid red led. Anyone know exactly what the flashing red vs solid red led while charging means? Googling it says that the blinking red just means it's not charging properly, but what does that mean, too low current? Too high current? Is it voltage related? My battery current widget doesn't show anything abnormal while the blinking red led is active... I'm stumped.
  • You need to stop charging it and turn it in for a refund.
  • This a joke? Why the hell are you still using that phone? Recall going on dude! Get it exchanged...
  • Depending on where you are some carriers do not have the replacement Note 7, while others offer a loaner phone until the new Note 7's come in.I've had no issues with my Note 7 and will continue to use mine carefully until new ones are available.
  • same here.....Note 7 (T-Mo...made in China), is working flawlessly.
  • How do you use a phone with a faulty battery more carefully? Any person with half a brain would switch to their old phone, borrow a unused phone from someone, or buy a $50 phone to use temporarily until it's exchanged. Bluestl, all the phones that exploded were working flawlessly before hand.
  • You are right....most of those were probably working flawlessly. Am I scared of my phone exploding?....absolutely not. I am not dumb to leave it in a car that is hot inside, I am not dumb enough to leave it unattended while charging, I am not dumb enough to charge it overnight. I have read that all the phones had RAPID temperature rises before they exploded or burned. I have my phone in my hand enough throughout the day (use it for work) that I would know if my phone was rapidly overheating and I would immediately turn it off. I even have an APP that tells me the temperature and lets me know that my phone is in danger of overheating....hasn't gone off once with this phone....with my LG G4......2 times a day. I am going to turn my phone in either today or as soon as they get the replacements (t-mo).
  • The only smart thing to do was NOT to use the phone until it was replaced since there is absolutely no reason for you to be using it.
  • It only became an official RECALL the other day. I don't want a cheap $50, get it set up, then 2 days later...have to do it again. There was so much misinformation out there....I could have got a S7 edge...but even that phone had a battery problem. Then, no one could guarantee that when I brought the phone back I could exchange it. Like I said, I am going to go in today and exchange it...if they have them.
  • Friend of mine puts ice pack on his and it cools down
  • Try using a non-approved charger with cheapest cable you can find.. I'm sure that'll fix your ticking time-bomb blinking problem...
  • Ensure it's a guage wire that is a larger number than 22... that will make it work.
  • That's really not funny I bought a Dollar Days phone charger my phone basically popped up in the air and to the ceiling causing a hole my landlord still wants me to fix
  • Wow...
  • I've been really liking the stuff Jerry has been writing lately. This one is probably one of the very best I've read. Learned quite a bit about lithium batteries. Will this push the development of alternative future power sources that store more power in a smaller package with less chance of combusting if something goes wrong? Sounds like the stuff of dreams, but one can hope, right?
  • http://www.ibtimes.co.uk/hydrogen-powered-phone-battery-could-keep-iphon...
    Hydrogen is completely safe
  • At least when it fails it will take the whole building with it in one shot. No one left to sue. I believe that death lawsuit damages are easier to settle than injury claims because of ongoing health care costs.
  • https://www.youtube.com/watch?v=KsjQZ2eXTxE Archer tells you all about it!
  • I agree. I'm hoping that these issues might spur research into new battery technology. Posted via my Moto X Pure Edition using the Android Central App
  • .
  • Good write-up Jerry!
    I turned my Note 7 in hoping we would get replacements soon. I could just wait for the Note 8 but I never got to see the full potential of my Note 7. I was thinking about the S7E, I heard several reports that some of those had battery issues too(fire, explosion, etc.....), but not as much as the Note. No real evidence.
  • No problem with the battery issue on my S7 Edge!
  • Very well written Jerry, a very informative read Thank You
  • Every time I read an article about these Note 7 battery issues I wonder if Samsung now regrets removing one of its formerly most popular features, the removable battery. I also wonder how much more this recall is going to cost them in the long run compared to if they could have just given everyone a replacement battery. Not to mention how much more peace of mind their customers could have had knowing that they could have just removed the faulty cell and replaced it on their own before waiting for a recall. They removed all of this convenience and peace of mind ultimately for what? A .5mm thinner device? Better planned obsolescence when the built in cell finally degrades and it is no longer fiscally justifiable to replace it. I'll concede that it probably helps make the device more completely waterproof, but that can still be done with a removable battery, it just requires a bit more effort and engineering. Honestly i think most manufacturers are trying too hard with the aesthetics of their devices these days. I have nothing against beautiful slim glass and aluminum phones for those who like that sort of thing, but personally I long for phones with flagship specs and simple tough polycarbonate bodies. I miss phones like my old EVO 4g and it makes me crazy that most phones now almost seem purpose built to be put into a case. The sad part is there are still a few manufacturers putting out simple durable devices but they never get the best hardware. If you want the best cameras processors memory, etc you are stuck with a phone that is almost entirely made of glass. It just seems insane to me. In all seriousness I'd almost be willing to wager that if a major device manufacturer were to actually step up and build a device where they skipped the fancy materials and stuck flagship guts back in to a solid durable body they would be shocked at how fast those phones would fly off the shelves. There is absolutely a pent up demand for a phone like this, and constantly fewer devices that are available to fill it. It seems every manufacturer is in a race to find the most premium materials to build their devices out of, and they have lost perspective of how people actually use them. Samsung's popularity was built on the back of durable plastic bodied phones and the only reason people keep buying them is because their customers keep coming back to the brand they know and if you want the flagship specs there's only one game in town. But that's just my 2¢. I apologize for the rant.
  • +1 this
  • I agree with you that aesthetics should take a backseat to function, but for YEARS everyone dogged on Samsung devices because of the "cheap plastic". They could never do anything to get people to shut up about it, even when the S4 and S5 actually looked premium, but maintained the plastics for functionality. So finally Samsung goes ahead and gives everyone what they wouldn't shut up about, and now we have form over function. So if you ever want to take your frustrations out on anyone, go back to the Galaxy S2, S3, Note 2, S4, Note 3, S5 threads and find any of the hundreds of people on this site who whined about plastic.
  • I completely agree. Honestly I don't get this need for so called premium materials. I want a phone that's light and functional and I would prefer a better display or more storage than a metal uni-body casing. In my opinion plastic is ideal for a phone because it's cheaper, lighter, less prone to dings, and allows for wireless charging. I like my S7 edge but I'd love it if it weren't so damn delicate. ...Joe K.
  • You're exactly right, but the problem is that the people complaining about the build quality of the older Samsung phones were the 1% of cellphone owners, the enthusiast crowd. They were trying to put Samsung up on a pedestal next to their biggest rival Apple and constantly falling short because their devices seemed less premium by comparison. The issue is that the vast majority of actual phone users don't comment on forums or phone reviews and were probably perfectly happy with their plastic phones. Honestly I know lots of people who actually complain about the fragility, or at least the perceived fragility of their newer Samsung devices and end up cocooning them in ridiculous multilayered cases to keep them safe. For what it's worth I think there is still definitely a place for devices made out of premium materials for the sorts of people who genuinely desire to have the best of the best. But your average Joe consumer would be thrilled to get a phone with the same horsepower, a more durable construction and without the stratospheric pricetag that accompanies the premium version. In this reality the manufacturer would probably be able to sell even more devices than before as they could make flagships that are more approachable and slightly more affordable and still charge a premium for those who still desire the best of the best. The sad part is that this would be almost trivial for Samsung (or most other manufacturers) to actually do. All Samsung would need to do is take something like the J7 stick the S7 guts in it and call it a P7 or something and sell it for $100 less than the S7. I guarantee they would sell like hotcakes. It would be a Win-Win situation for Samsung and consumers. The new version would be cheaper to build so Samsung keeps the same profitability but sells more devices to the thrifty shoppers who still want a powerful device but doesn't care about the premium build. While they still have their premium flagship phone out there to go toe to toe with their competition and the customer base that craves them... Although at the end of the day the ironic part will be when both the buyer of the premium phone and the plastic phone both stick them in TPU cases and ultimately have identical devices anyway.
  • I absolutely loved the design of the S3. Curvy, it was a tank of a phone. My wife dropped it out of her purse on the driveway and drove over it. It had a plastic case on it but it was totally fine. I had an extended battery that worked well with a bigger back cover that you could install over the battery. *sigh* I hate glass on the back of phones, especially when I use a case which covers it up. And, you need a case to protect the glass. *sigh* Samsung listens to the wrong consumers.
  • exactly......the nice looking $850 phone looks good until you put it in a $20 case....then it looks like any other phone.
  • S7 Active Posted from my unlocked S7 Active on T-Mobile / Hot Note 7 / or my peerless Note 4
  • The S7 Active was close to getting it right but crippled by only being released on one carrier. Yes you can get it unlocked and use it on another carrier (obviously I don't have to tell you this). But it is a convoluted process that the average consumer doesn't have the time energy or knowledge to bother with. Plus this is a purpose built ruggidized phone, which is kind of going too far in the other direction. I was referring to something that theoretically would fall somewhere in between the Active and normal Galaxy phones.
  • @Slow_S10
  • I never moved on from my Note 3, I'm not a gamer and just need basics. Batteries are stored energy, so the option to swap them in seconds or simply remove them (if they behave badly) seems obvious - if not essential. Provided Samsung guarantee reliable access to original quality replacements, its a perfect & far safer approach. In the RC world LiPos are all charged well away from devices, under observation, away from flammable surfaces, with thermal cutouts. I have 3 carefully sourced batteries for my Note 3. Often charged outside the phone, under observation. The phone & OS is obsolete, but I prefer the thermal safety & control I still have. I will consider a V20 or something mid range than meets my needs. A phone is not a fashion statement, just a tool.
  • Thank you! good rant, I agree.
  • As I was reading this, I'm thinking: gosh, Jerry must be an EE or something. LinkedIn confirmed. Really good article, thanks for being so thorough and taking the time to do it. This is the perfect article for the engineer/tech enthusiast demo. (the former does not beget the latter as much as I would expect)
  • Off subject**** Where's Phil? I haven't been on this site in months
  • http://forums.androidcentral.com/showthread.php?t=709251
    Phil's "departure" See also one of Jerry's blogs this week. About to do something exciting, apparently. We know not what.
  • buying a Sony phone
  • this whole thing about batteries is scary, now i am scared to even hold my phone . x(
  • I have a Galaxy Note Edge and it will get very hot at times. If I have it in my pocket on a hot day it will be nearly too hot to touch. I carefully pull the battery and wait until it's all cooled down before I reassemble it. A removable battery at least gives me the option to do this. I think overheating has always been an issue.
  • This also happened to my daughter's Note Edge and I noticed the back plate bulging so I turned the phone off, removed the back cover, and noticed what was bulging was actually the battery. I disposed of the battery and got her a new one and everything's been working great since. Posted from my unlocked S7 Active on T-Mobile / Hot Note 7 / or my peerless Note 4
  • Can't Samsung push some type of nag warning to these devices that can't be turned off?
  • Saw someone say this a couple of days ago and it seems like a good solution. Every time it's unlocked or every 15 minuses of use pop up a full screen notification telling them to stop using the damn thing.
  • I recently bought a Moto X Pure, but kept my Note 3. I have an extra battery for the Note 3, which was the old one. I was just looking at it, and it had a slight bulge on the side opposite the contacts. The one in the phone doesn't have this. Now, I'm wondering if this is something to be concerned about (it's not in a phone), and wondering if my Moto X battery is going to be a problem. To be honest, this battery problem is a little scary, when you think of phones laying around the house, with little ones in the house. I wear mine, due to hearing problems. Strangely enough, I was waiting on the Note 7 to come out, but when I decided that a Motorola at 1/2 the price would still work for me, I went cheap. I LOVE my Samsungs, but not $800 worth.
  • If you have a battery with a bulge in it, stop using it!
  • Yep I agree with you there I dropped my phone one time and then the ZTE phone battery was coming out from the back and started leaking
  • I had a 40 watt Lion battery go exothermic in my living room about four years ago, had to move out of the house for six weeks and it cost about $35,000 to fix.
    I was well aware of the danger from these batteries, and bought end tables with slate inlays. I also bought ceramic tiles from 6" x 6" up to 12" x 24", specifically to charge things on. That saved me from losing the house, because the fire occurred on a fireproof surface.
    I work from home, so I was here when the fire started.
    Do not throw water on a Lion battery fire, only use a tri-class extinguisher. That is another area where for foresight payed off, every room has a ten pound tri-class extinguisher, and there are larger ones up to twenty pounds located in strategic places.
    After burying the burning battery pack in yellow extinguisher powder I picked the whole table up and carried it out of the house.
    When these tings burn it is a very hot fire, and they would burn through a table and then through the floor in short order. Ronald J Riley Electrical Engineer
  • I had a 40 watt Lion battery go exothermic in my living room about four years ago, had to move out of the house for six weeks and it cost about $35,000 to fix.
    I was well aware of the danger from these batteries, and bought end tables with slate inlays. I also bought ceramic tiles from 6" x 6" up to 12" x 24", specifically to charge things on. That saved me from losing the house, because the fire occurred on a fireproof surface.
    I work from home, so I was here when the fire started.
    Do not throw water on a Lion battery fire, only use a tri-class extinguisher. That is another area where for foresight payed off, every room has a ten pound tri-class extinguisher, and there are larger ones up to twenty pounds located in strategic places.
    After burying the burning battery pack in yellow extinguisher powder I picked the whole table up and carried it out of the house.
    When these things burn it is a very hot fire, and they would burn through a table and then through the floor in short order. Ronald J Riley Electrical Engineer
  • Awesome, not for your troubles, but thank you for your insight.
  • Regarding AC's coverage, advice and returns threads per carrier: great stuff, but I am very annoyed NO ONE started a TOTAL RECALL thread, with reference to Terminators, It'll Be Back etc etc. Shame :p
  • All lithium batteries are potentially flammable. It's time to move on to a newer battery technology that offers better performance along with being non-flammable like perhaps metallic sodium from Broadbit. http://www.ksdk.com/news/local/5-on-your-side/iphone-explodes-in-st-pete... http://www.pressherald.com/2014/01/31/kennebunk_student_s_cellphone_catc... http://www.usatoday.com/story/news/nation/2014/02/01/newser-iphone-fire/... http://www.nbcphiladelphia.com/news...Phone-Caught-Fire-In-My-Pocket-303... http://www.khou.com/news/local/man-describes-how-iphone-6s-catches-fire-... http://www.nbcnews.com/tech/tech-ne...-after-iphone-catches-fire-mid-fli... http://www.fox5atlanta.com/news/66037216-story http://www.ejinsight.com/20150706-tai-wai-womans-iphone-6-plus-explodes-... http://www.fox10phoenix.com/news/1648947-story
  • I have over the years tossed metallic sodium into a pond to demonstrate that it is also very dangerous. It will briefly dance around and then explode.
    Anderson University sodium toss (explosion) - YouTube
    Clearly we need high power density batteries, but as it stands, the stored energy of the battery is dumped and then dumps the chemical energy, all in under a minute.
  • It's too bad OEMs don't make phones with removable batteries you know, in case they explode. If only there was a way for the user to just pop in another battery...
  • Question : Which material is best to protect you against such a thing (battery explode or whatnot) ?
    Would a plastic be better for the device? Or metallic device?
  • From a safety standpoint. a plastic phone with a non-removable battery would be best. Plastic will flex and crack to let a battery expand, and the pieces are probably less dangerous than bits of glass or metal if the phone does explode. A removable battery has a much thicker case. If it bursts, you are facing a much bigger explosion (because it requires a lot more pressure to breach the housing) with actual hard pieces of "shrapnel" instead of the bits of metallic foil that house an embedded battery. Every time I read about how much better this situation would be if the phone had a removable battery, I wince a little and am glad it doesn't have one.
  • Replaceable battery matter this much?
  • While having the thicker casing on a removable battery makes it more dangerous in the event of catastrophic failure would you not agree that a recall in that scenario would be faster and more simple to do (which would in effect leave a dangerous device in people's hands for less time)? That plus it would be much more cost-effective than to replace the whole device. Posted from my unlocked S7 Active on T-Mobile / Hot Note 7 / or my peerless Note 4
  • There is no way I would use an existing Note 7 with a different battery. Samsung isn't being very open about what is causing the problems (they don't have to be, so no foul) and has said three very different reasons that don't make a lot of sense from an engineering standpoint. The latest reason for the battery failures from Korea is so silly it's almost laughable. Unless I could verify the charging circuit, the overprotection circuit and the actual placement of the battery were fault free, I'd want a new phone with Samsung's guarantee that it doesn't have the known issue that the current models have. There are plenty of reasons to want to swappable battery in a portable device. Safety isn't one of them.
  • It depends on the reason. If it's only the battery, it should be ok to just replace it. If it's more than that, maybe you should replace the device.
  • I think you wanted to write this as a reply to someone else. I wrote about which material is better for this scenario.
  • This is very important information relating to removable batteries.
    So they are far more dangerous, or can cause worse injuries.
    Didn't know the casing was much thicker. This should be added to the blog. Give removables die - hard's something to think about after recent events.
  • Great article! I now have a better understanding on how these batteries function.
  • This article is an incredible write-up. I hope Samsung will go with a removable battery for the Galaxy S8 and Note 8 next year.
  • Just like laptops, software should not allow the battery to be overcharged. Dell says the batteries do not overcharge even they are plugged in. I can't understand why not Android or Samsung any other OEM?
  • They do. It just didn't do its job this time.
  • Is swelling natural? One of my PS3 controllers stopped working (woldn't charge). I opened it, and the battery had swollen to double thickness at the middle. And this is an original Sony battert. Kind of scary :-(
  • It's fairly common on older batteries that have been charged a lot of times or left in place (completing a circuit) while not completely drained. A swollen battery is never good and you should always toss it out, but unless it rapidly swells and not over time, it's not an "emergency" situation. Toss it. Buy a quality replacement and you'll be fine.
  • Yep. Bought a new one. Strange btw. The original battery was in a "holder". The new one was larger (physical and capacity) but fittet perfect if I removed the "holder". Why does Sony put in a smaller battery?
  • That could be a safety thing, too. Battery science has come a long way since Sont started making the PS3, and they might be able to make larger batteries that are just as safe (the smaller the battery, the smaller the damage if it pops) as smaller ones were 10 years ago. Or it could just be Sony is crazy :P I love Sony products, but they are a really strange company.
  • It's not just note 7s, my internet router had a bulging battery I had to replace... At least Samsung are doing the honourable thing with the recall. Now, if it had a removable one, it would be much easier (cheaper)..., just saying
  • Omg it's such a shocker that something can actually explode when on everyday triple a batteries say not to open the damn things! Why don't people know about this yet! (. This has been known since the battery was invented... Nothing new)
  • Such a nice article, i loved it and its really easy to read. Great work Jerry!
  • I know my comment is WAY down here on this one and way late probably, but this article was really well done. It sounds cocky here, but I did infact already know all of this, and thus I mention that because it is accurate. How I knew this was because of the training I recieved in the Marine Corps. I was an electiricain on the greatest fighter jet in existence, the F/A-18 Hornet (bias much?). That sucker has two massive batteries with a ton of power. Tons more power went to them. If these things were ever hot or looked like they were buldging in any manner we alerted EOD and they brought over bomb boxes and took them batteries immediately to an explosives area where they could detonate on their own. Some times they didn't... but I can tell you as I was around one (that goodness only one) that the detonation was massive. It's a thermal explosion. Thermal just... well, think of thermite. It's designed to burn at an extemely hot temerature. When not actually doing anything, it's inert and just any normal old substance. But, when it gets started through its chemical reaction there is literally no stopping it. Great write up. Truly enjoyed it. Brought me back to some good times!
  • Well several things can cause a battery to explode and I will share those with you. Microwaving; yes it will blow battery up n hot pockets will taste better. Being overweight: YES, sadly if you sit on it with your fat butt it will explode battery. Drake; any song by him will detonate phone