WARNING !!  Faulty Laptop Batteries... - Page 1
Forum section: electronics / general

author: GlennSprigg
author_rank: Super Contributor
timestamp: November 19, 2018, 12:05:18 pm
content: One of my main Laptops, (that I actually love!), is anAcer Aspire R7 571and recently it wouldn't power-up.Even with the power-cord attached, and the LED's showing power attached, & turned on. (More on thatLATER!).Disassembly, (yep... with a long flat internal battery), soon revealed the problem with the battery-bank. Photo...https://imgur.com/a/OsuHLuHThe original, which was aLithium-Ion(which is typical/ok generally), was bulging badly & about to burst!!!This Laptop was brand new, about 2+1/2 to 3 years ago. Generally, I leave the power-supply plugged in andturned on all the time. I'm not sure if this should/could cause a charging problem though ??The replacement Pack, (obtained from Interstate here in Australia), is actually aLithium-Polymertype.Researching on the Net, revealed that the Lithium-Ion packs can suffer from this, like some SmartPhones have.Where-as the Lithium-Polymer packs do not!!?? However, they also say that Lithium-Polymer has slightly less'grunt' and can often cost more. If so, then I would RATHER that !Anyway, to finish off as a side-note, from my 1st paragraph, I was thankful for YouTube before Re-Assembly !!The battery-pack has additional sensors inside, and the MotherBoard has some nefarious(?) functions thatno-one can explain, whereby you can NOT just put a new battery in and power it up !?Firstly, there is a microswitch on the MotherBoard that has to be pressed for 4 secs afterwards, with thepower-cord unplugged, and then the Laptop UNTOUCHED/operated/plugged-in for up to 20 minutes...THEN, (usually) upon 1st powering up, you have to press the Power-On button and hold it, for at least 45seconds. Upon releasing it, it will either start up straight away, or after another brief press...Evidently, it's been the Bane of many a confused & frustrated owner !!!

author: Nusa
author_rank: Super Contributor
timestamp: November 19, 2018, 04:23:21 pm
content: The full name would be "lithium-ion polymer battery". Which subset or abbreviation of those words gets used depends on the writer. Your original battery was probably of this type as well, since virtually all flexible pouch-type cells are.

author: janoc
author_rank: Super Contributor
timestamp: November 19, 2018, 05:04:28 pm
content: Lithium-polymer is the same chemistry as Lithium-ion, it is typically a misnomer meant to denote these flexible pouch cells (as opposed to e.g. 18650 cells).There exists a type of battery with an actual polymer electrolyte but those are quite rare.

author: wraper
author_rank: Unknown
timestamp: November 19, 2018, 05:15:21 pm
content: Read what's actually written on batteries. Both of them are lithium polymer.

author: james_s
author_rank: Super Contributor
timestamp: November 19, 2018, 05:18:52 pm
content: It's quite common for these to bulge, especially if they are overcharged or over-discharged. It can also happen if they are overheated, one of the guys I occasionally fly RC airplanes with left a battery on the seat of his car on a hot day and it puffed up like a balloon.

author: janoc
author_rank: Super Contributor
timestamp: November 19, 2018, 05:46:47 pm
content: It will also happen with age - the chemistry produces oxygen gas which will accumulate over time. That's why an old battery that doesn't maintain charge anymore is typically swollen as well. Then it only takes an ignition source (e.g. a small internal short) and the thing goes BOOM.OP's 3 years old "brand new" laptop could easily reach this part of the battery life if the machine was used on battery regularly. LiPos have lifetime of only about 500 charge/discharge cycles which is easily achievable in 3 years (depends on usage, of course - if the laptop is all the time on AC then the battery gets little use and can last a very long time).

author: cdev
author_rank: Super Contributor
timestamp: November 19, 2018, 10:13:36 pm
content: Do they explode? A few years ago I had a laptop battery that expanded like that and when doing research on what was happening I saw several stories about them literally exploding on people. Luckily nobody that I read about was killed, but it seems there is a very serious fire risk.This is the #1 reason electronics using people should both take care to not try to keep recharging these old batteries and also have a fire alarm in their home, one thats in good working order.

author: timgiles
author_rank: Regular Contributor
timestamp: November 19, 2018, 10:36:25 pm
content: So BS, they do explode or they dont?

author: janoc
author_rank: Super Contributor
timestamp: November 19, 2018, 10:41:18 pm
content: Quote from: cdev on November 19, 2018, 10:13:36 pmExplode (as in detonation) by itself not really but it can burst and catch on fire.Lithium has a nasty nasty property that it will burn easily when exposed to air or water (plus it generates hydrogen when in contact water -thatcan explode). So such fires can be pretty dangerous because pouring water on it will only make things worse and it generates its own oxygen so it is difficult to smother it out.You can find videos like this:https://youtu.be/gz3hCqjk4yc?t=40There is looks like the battery has exploded but it was both swollen due to intentional overcharging and the guy has damaged it - that causes an internal short, lots of current will flow, things get very hot and the battery will ignite and burst, shooting flames out. If you don't damage it mechanically it won't fail with a fireball like that, at worst it will burst and burn - like the many videos of laptop battery fires.If the battery is swollen, certainly do not attempt to charge it again and dispose of it safely.EDIT: Removed the metallic lithium mention, apparently I am bit behind the times - the first lithium batteries did, in fact, use metallic lithium electrodes, today it is more lithium oxide which doesn't ignite in contact with water. However, the electrolyte is flammable and when the battery shorts out/fails, the resulting thermal runaway will ignite it.

author: digsys
author_rank: Unknown
timestamp: November 19, 2018, 11:09:13 pm
content: Can anyone tell if my EV batteries are suffering this phenomenon? I seem to only get a few Km now.

author: cdev
author_rank: Super Contributor
timestamp: November 19, 2018, 11:29:43 pm
content: Ouch!

author: Halcyon
author_rank: Unknown
timestamp: November 19, 2018, 11:32:24 pm
content: As much as you like Acer, their gear is pretty bottom of the barrel stuff.I have an Acer Chromebook 720 right next to me at the moment with exactly the same problem.

author: Halcyon
author_rank: Unknown
timestamp: November 19, 2018, 11:36:30 pm
content: Quote from: blueskull on November 19, 2018, 11:34:33 pmYes but their "top of the line" isn't industry "top of the line".I've used their enterprise workstations as well and they aren't great compared to what HP and Dell are doing.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 01:10:50 am
content: The amount of metallic lithium in a li-ion cell is negligible. The fire is not from burning lithium but from flammable electrolyte vaporized by the self heating of the battery when a short occurs.These shorts can be caused by mechanical damage or a manufacturing defect, as well as material building up on the electrodes , when the cell is overcharged they can get thick enough to puncture the thin separators. Puffing is not really a cause of fire but one of several symptoms of a damaged or degraded cell.

author: amyk
author_rank: Super Contributor
timestamp: November 20, 2018, 01:36:27 am
content: In technical contexts, there is a difference between explosion and "vent with flame". To the non-technical person, there is not much of a difference. The former throws shrapnel everywhere, the latter is more like a gas torch.Bulging is often caused by exceeding the voltage or current limits. Fire is rare, even when the cells are punctured, unless the deformation or puncturing object causes a short. In fact bulging tends to delaminate the electrodes, reducing capacity and active plate area, and thus also short-circuit current.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 04:21:14 am
content: The only times I've seen LiPo fires were charging accidents and crashes. The charging accidents are more common than they ought to be, usually caused by defective or improperly configured chargers that allow one or more cells to over-charge. If you keep on charging a LiPo the voltage will keep rising and eventually it *will* catch fire.

author: tooki
author_rank: Super Contributor
timestamp: November 20, 2018, 04:30:32 pm
content: Quote from: janoc on November 19, 2018, 05:04:28 pmIndeed, when non-cylindrical Li-ion batteries came out, they were called “prismatic” cells (some were in plastic or metal boxes, others were the pouches). The terminology has becomereallymushy, since people use the terms variously to mean different things, erroneously believing their narrow definitions to be the sole correct ones... :/

author: kerouanton
author_rank: Regular Contributor
timestamp: November 20, 2018, 05:07:49 pm
content: Same issue with my old MacBook Air 11''. I stored for a few months since I had my new Macbook Pro, and when I retrieved it from the closet, the batteries had inflated, and literally torn apart the aluminium case...Apple support told me it was "normal" as they hadn't exploded but "only" expanded

author: Kleinstein
author_rank: Super Contributor
timestamp: November 20, 2018, 06:17:58 pm
content: The Li polymer cells are different from conventional LI _ion cells by more than just the case. They also use a different type of electrolyte / separator. The electrolyte is actually the polymer that gives them the name, not the case.Getting rid of damages Li cells can actually be a little tricky - depending on the country damaged LI cells (especially larger quantities) are considered dangerous good that might need a special permit for transportation. There usually is an except so one can bring small quantities to local disposal sites.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 06:21:36 pm
content: Quote from: kerouanton on November 20, 2018, 05:07:49 pmTechnically it is "normal" for this type of cell to expand as they deteriorate. The issue is designing the computer such that the cells can't expand non-destructively but that's Apple for you. Despite their claims of being environmentally friendly, they want you to replace your devices every 2-3 years.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: November 20, 2018, 08:09:45 pm
content: I've acquired at least four Acer laptops and netbooks from various sources. Mostly cast-offs. So far only one remains in the land of the living.A colleague bought one new and had it die just out of warranty.Presently using a Dell laptop. It's had some pretty rough treatment and it just keeps going.The early Venue tablets had some reliability probs but I think they've fixed them now.Apple are good quality but just not worth the silly money you pay for them. Plus they are hard to repair.

author: cdev
author_rank: Super Contributor
timestamp: November 20, 2018, 08:15:24 pm
content: How can somebody prevent this from happening?Some Apple laptops don't even have removable batteries.Quote from: james_s on November 20, 2018, 06:21:36 pm

author: Jeroen3
author_rank: Super Contributor
timestamp: November 20, 2018, 08:44:43 pm
content: Quote from: janoc on November 19, 2018, 10:41:18 pmJust to get one big lie out of the world.Batteries with lithium do not explode when in contact with water.(as mentioned byJames_s)In fact, the procedure for fire of or in a device with a lithium battery is to submerge it in water.Even Tesla's fire chapter in their first responders guide notes:Quote from:https://www.nfpa.org/-/media/Files/Training/AFV/Emergency-Response-Guides/Tesla/Tesla-Model-3-EV-2017-2018-ERG.ashx?la=en(yes, it is written in caps)Or what if there is a batter firein a plane?The goal is to keep the battery cool to prevent more fire, or spreading it to more cells.When there battery is spewing flames or is gassing, it has shorted internally and is heating up incredibly fast.Cool it down. Water needs a lot of energy to heat up.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 09:08:23 pm
content: Quote from: cdev on November 20, 2018, 08:15:24 pmAvoid over or under-charging the battery, avoid excessive temperatures, check them regularly for the first signs of puffing, refuse to buy products that have prismatic cells permanently installed within them, that's about all you can do really.

author: janoc
author_rank: Super Contributor
timestamp: November 20, 2018, 11:21:50 pm
content: Quote from: Jeroen3 on November 20, 2018, 08:44:43 pmI never said that thebatterywill explode in contact with water but that the metallic lithium will generate hydrogen gas which could explode (if left to accumulate). That's not quite the same thing.However, you are right that current batteries don't really contain metallic lithium in any appreciable quantities, so this is a moot point. I have corrected my original post to not mislead people.

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 11:36:35 pm
content: Technically the mechanism by which alkali metals "explode" when dropped in water is the liberated hydrogen recombining with the oxygen explosively, but I think it's still reasonable to say that the metal explodes. That requires of course dropping a lump of the metallic element into water, which is not something that's going to happen with Li-ion batteries.

author: tooki
author_rank: Super Contributor
timestamp: November 20, 2018, 11:40:35 pm
content: Quote from: cdev on November 20, 2018, 08:15:24 pmSame as an iPhone or iPad: take it into an Apple Store and they'll replace the battery. Or if the battery cannot be safely replaced in-store, they replace the whole unit for the cost of the battery replacement. (And then they do the refurbishment off-site.) Of course if it's under warranty or AppleCare it's free, since a bulging battery is considered failed, not just worn out.(And before anyone makes up crazy numbers for what the battery service costs, depending on MacBook model it's between $130-200 including installation, so the same as first-party replacement batteries for most laptops.)

author: james_s
author_rank: Super Contributor
timestamp: November 20, 2018, 11:48:42 pm
content: Unless your machine is more than about 3 years old, in which case they may declare it "vintage" and try to sell you a new one. I do like my iPhone but I don't like Apple's attitude and I also recognize that by being someone who keeps a phone or computer for 5+ years I'm not the sort of customer they are really interested in having. I've had to go way out of my way to prevent my iPhones from auto-updating to the latest iOS, left unchecked they always seem to update older devices one or two versions too far at which point they become unusably slow. I'm the sort who wants to buy a device, get it set up exactly how I want it and then lock it down for the life of the device. I don't want new features, I want it to keep working as well as the day I bought it until it is worn out or no longer meets my needs.

author: bd139
author_rank: Super Contributor
timestamp: November 21, 2018, 09:00:24 am
content: Quote from: james_s on November 20, 2018, 11:48:42 pmIf you like it or not, the device needs updating for security reasons. People (and manufacturers) who don't update their devices are as good as good as anti-vaxers and end up in botnets causing all sorts of trouble for other people and themselves.Quote from: tooki on November 20, 2018, 11:40:35 pmI've only actually had to replace the battery in one Apple product within 6 years and that's my daughter's iPhone 5 (not even S) a week ago. That had a bulging battery. Was scooped out and replaced for $10 (including tool kit and battery!)

author: janoc
author_rank: Super Contributor
timestamp: November 21, 2018, 03:02:48 pm
content: Quote from: blueskull on November 21, 2018, 12:23:41 amYou have likely never seen someone dropping a piece of sodium (easier obtainable than metallic lithium) in water and what it does. The reaction is very exothermic (to the point of generating sparks) and generates copious amounts of hydrogen gas and the matching hydroxide. At some point the burning metal will ignite the escaping gas and you get the characteristic bang. Lithium and potassium behave exactly the same as sodium. This is very much chemistry 101.Here is an explanation of why the explosion happens (including video):https://cosmosmagazine.com/chemistry/better-explanation-why-sodium-explodes-waterThunderf00t's video on the subject actually refers to exactly this. The issue there wasn't whether or not it explodes because of the explosive hydrogen reaction (that isn't in dispute - it simply does) but the fact that the escaping gasses should have stopped the reaction by insulating the metal from the water. The video shows that this doesn't happen because the metal grows "spikes" on contact with water that increase the surface area exponentially, keeping the reaction going.Now to be clear before someone jumps on me -this is notthe reason why a lithium battery "explodes".

author: tooki
author_rank: Super Contributor
timestamp: November 21, 2018, 03:33:40 pm
content: Quote from: james_s on November 20, 2018, 11:48:42 pmNope,it's at 5 years, not 3, that mainstream support ends. And the fact that Apple usually provides major software upgrades for devices up to age 5 is further proof that Apple isn't pushing for artificially short longevity. (Another form of evidence is the fact that Apple devices are used, on average, appreciably longer than competing products (on average, across all products, 4 years:https://www.techrepublic.com/article/heres-how-long-your-iphone-will-really-last/.In businesses, PCs are normally on 3-year replacement cycles, Macs on 4.)And while some iOS upgrades have led to noticeable slowdowns, iOS 12 is actually massivelyfasteron older devices than iOS 11 was. (On newer devices, the difference is negligible.)

author: bd139
author_rank: Super Contributor
timestamp: November 21, 2018, 03:48:44 pm
content: Indeed. My MBP is 2013 and still supported. Also hasn't needed a battery since new. Still get 4 hours out of it. I just sold the newer unit I bought a couple of years back because the older one is fine still. I think the iOS slowdown thing is over now. I've got a 3 year old 6s and it gets faster every release.

author: james_s
author_rank: Super Contributor
timestamp: November 21, 2018, 05:37:28 pm
content: I still use a number of 32 bit apps on my phone, so anything past iOS 10 is a non-starter for me. There's a lot of FUD surrounding older versions of software but I don't buy it, every single malware/virus I've ever seen has been the result of not an exploit but user error. Every single one, and I have cleaned up many dozens of infected machines over the years. People install sketchy stuff and get infected. I have *never* seen an infected iOS device of any generation. People have been screaming that the sky is falling for more than a decade and continuing to use old versions of various software has not bit me yet. The dangers are largely a lie perpetuated by those who have a financial interest in selling you the newest version.I have witnessed firsthand the generation of said FUD, it's a ploy to get people in the habit of buying new devices and being on the latest, "greatest" and most monetized version of everything because that's how tech companies profit. When the market became saturated and tech plateaued people stopped upgrading every year or two and companies started to panic. Just look at the way Win10 was pushed out aggressively with Microsoft spreading FUD about their own prior (and still fully supported) versions of Windows and now we have the rental software epidemic spreading like wildfire with so many products going subscription only. It is spun as beneficial to the consumer, but of course the only benefit is to the company producing it as they no longer have to come up with compelling new versions that will entice people to upgrade, all they have to do is keep the product just good enough that people keep using it and thus keep paying. It's a scam.

author: bd139
author_rank: Super Contributor
timestamp: November 21, 2018, 06:22:50 pm
content: It’s not FUD. I work in the security side of software engineering mostly and there are plenty of targeted iOS attacks.Your funeral. That’s all I’m saying.

author: Jeroen3
author_rank: Super Contributor
timestamp: November 21, 2018, 07:02:26 pm
content: Quote from: james_s on November 21, 2018, 05:37:28 pmEver seen ajailbrokeniPhone?Remember the time you could jailbreakwith a PDF?Click on some links to seewhat vulnerability they use.But please keep using ancient stuff.Back to batteries.How much elemental lithium is there in a lithium battery?

author: tooki
author_rank: Super Contributor
timestamp: November 21, 2018, 10:16:53 pm
content: Quote from: james_s on November 21, 2018, 05:37:28 pmNobody was talking about security issues — stop moving the goalpost.Most people don’t know, or care, about security. But new features, that they like.Now, as bd139 and jeroen3 said, it’s true that security updates are a real need and that real vulnerabilities have existed. But I also agree with you that on the whole, iOS has proven to be remarkably secure overall.

author: james_s
author_rank: Super Contributor
timestamp: November 21, 2018, 11:30:30 pm
content: Quote from: bd139 on November 21, 2018, 06:22:50 pmA bit melodramatic don't you think? As if a security breach on my phone is going to kill me, I'd just reset it to factory defaults and go on with my life. Jailbreaking doesn't count, if you have physical access to the hardware then all bets are off, although even then it is incredibly difficult to find untethered jailbreaks for the last several versions of iOS. Find me a case of an iOS device compromised by an external attacker, I haven't come across any. We're talking consumer machines here, not servers facing the outside world which obviously need to be kept up to date.Anyhow I have here an iPhone running iOS 10 connected to the internet, and just to make things interesting, I just fired up an ancient laptop running WinXP, also connected to the internet which I'll leave going for a few days. Oh and there's an ancient iPad running iOS 9 too. They're all behind a firewall but that's going to be the case just about anywhere. I'll offer US$500 to the first person who can pwn any of these devices and post some kind of proof here, no joke, you all now have as much knowledge about these particular machines as anyone else in the world aside from me, so please demonstrate how vulnerable they are. I've had people hand-wringing and screaming that the sky is falling and I was gonna get hacked for at least a decade now and it hasn't happened yet so I just don't buy that it's anywhere near the risk that some people claim, and it's going to take a breach to change my mind.

author: bd139
author_rank: Super Contributor
timestamp: November 21, 2018, 11:51:22 pm
content: Like I said before, your (arrogant) funeral. Enjoy Cryptolocker or something.https://googleprojectzero.blogspot.com/2017/04/over-air-exploiting-broadcoms-wi-fi_4.htmliOS 10.3.1 was first patch rev. iOS 9 is not patched:https://support.apple.com/en-us/HT207688What's your IP address?

author: GlennSprigg
author_rank: Super Contributor
timestamp: November 22, 2018, 11:31:07 am
content: Quote from: wraper on November 19, 2018, 05:15:21 pmOOPS!!!I can't believe I was that 'stoopid' haha...I think what I saw on the OLD battery was THIS part......THANKS to all, for their insight and information. That's what Forums are forUmm... I was a bit confused with the 3rd answer to this post, by 'blueskull' from China...."Please don't work on batteries if you don't fully understand it."Well, I wasn't 'working-on' or 'playing-with' batteries, but simply opened my Laptop, observed the obvious,and replaced it, with what I was told was a replacement! However, I had some tech questions about battery types.(I was an elect/tech for 45 years now retired, but modern battery design is not my fort'e.)Re: the 'Acer Aspire R7' choice, I like the Touch-Screen 'Easel' design, like a large 'Touch-Pad' when wanted.Here's a short video to show it, (in German!!). I think he said... "It is mindbogglingly goot, Yaa?"And that the Touch-Pad wasabovethe keyboard, out the way, unless needed. (I HATE Touch-Pads!!)I understand peoples concerns/opinionsShortly, I will add the most ridiculous access to remove the 'Keyboard' for this MC, that I have ever seen !!!

author: MrMobodies
author_rank: Super Contributor
timestamp: November 23, 2018, 12:39:09 am
content: When buying lithium the batteries I am paranoid.I have got a HP laptop and someone already opened it up and the reason the fan didn't work is because whoever had it didn't reconnect it properly when putting it back. There are burn marks in the battery compartment and a blown regulator on the board. The battery is a "LAP Power".Battery has a date sticker.I did find it on Amazon with very bad reviews but nothing about blowing up the board.Now I can't find it to show here but I think they changed the name to Lapcare as it looks similar and they look like Indian brands.It has a date stamp 21/01/18 from "Laptop Town BD" and I got the laptop in July and it is still on my shelf for them to collect.I suspect the battery might be responsible.Quote from: bd139 on November 21, 2018, 11:51:22 pmI know there was something like that where someone can cause certain access points to reboot and there was a window where you could join on bootup and they would try the default passwords something like admin/admin but that's all changed now.I don't trust Wifi. I once put a 3g modem in a Portacabin setup and had some dedicated access points all set with different passwords for different things.One day they were complaining of a very slow connection and unable to read their emails and do work in the office there.I went down there one day and I saw lots of traffic with only one device connected with a weak signal but all of the workers left and went in the flats to work and I was the only one there. As soon as I disconnected the access point in question the loud blasting music playing stopped which was coming over from a different lot of flats nearby.When I reconnected it the and loud blasting music turned on again.The flats it was coming from had nothing to do with the work.I had to change the passwords of course and really tighten things up and use mac address filtering.I put some firewalls in there and stuff to monitor and manage the traffic remotely.That put a stop to it.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 23, 2018, 07:28:26 am
content: It's important to understand that the term "lithium polymer" is a completely meaningless marketing term. This is really kind of a facepalm thing in the battery industry, but we need to play along, because marketing guys want "lithium polymer" batteries.This may not be exactly accurate historical representation, but AFAIK this originates from the 90's research trying to replace the liquid electrolyte present in the li-ion cells with a solid polymer electrolyte - the term "lithium polymer" was coined to describe this new battery, which was going to be significantly different (improved safety was stated as one of the big goals). This never took off, but the marketing guys wanted to reuse the name, so, bog standard lithium ion products started to be randomly called "lithium polymer". And, of course, when one player does it, everyone else needs to have "lithium polymer" as well! This is the way competition works.And see, it's workingextremelywell. Foryears, people were like: WOW, this isn't lithium ion - this is LITHIUM POLYMER!!!1So this is really kind of "emperor's new clothes" thing.Now, the way "lithium polymer" term is used today, tends to mean "pouch form factor". The internal construction is exactly the same with the electrodes and a porous separator sandwitched together, filled with a small amount of liquid electrolyte.If it's rolled up and put in a steel container (like in 18650), it's typically not called "lithium polymer". If it's rolled as a flat roll, then packed in a aluminium laminate plastic pouch (similar to ESD bag material), then it may or may not be called "lithium polymer" or "lithium ion polymer".In the end, it doesnt't matter. It's all li-ion, it's all the same.What really matters, is the manufacturer and their product quality.Given a very strict definition for "explosion", li-ion batteries don't explode, not even close. But, they can burn rapidly in an exothermic reaction (with their own internal supply of oxygen available!) that looks and feels like what some laymen call "explosion", and shoot the flammable electrolyte out as a large flame. The only way to stop this reaction is to cool down the cell at a rate higher than the rate of internal heat generation. The only way to provide such amount of cooling is using large amounts of water, and it's difficult even then. But, water has very good chances of protecting adjacent cells from hitting the thermal runaway temperature (around 160 degC) in multi-cell packs, even if you failed to stop the already combusting cell. The energy release is notthatmassive - the multi-pack fires tend to spread fairly slowly, in minutes instead of seconds, so fighting it with water is possible if you have a lot of water nearby.

author: bd139
author_rank: Super Contributor
timestamp: November 23, 2018, 07:56:24 am
content: Quote from: Jeroen3 on November 23, 2018, 06:51:00 amCor that guy was an idiot. How to change a MacBook Pro battery (I have done it):1. Fire up the MacBook and run a CPU benchmark until the battery is dead and it shuts down by itself.2. Crack it open3. Disconnect battery4. Use a craft (not industrial) heat gun on the top of the unit just to warm it up a bit and soften the advesive5. Use a credit card to slide under the individual packs.5. They come right out!He went at that with a metal scraper straight up and punctured the cells. Idiot. A monkey could have done a better job.

author: MrMobodies
author_rank: Super Contributor
timestamp: November 23, 2018, 08:16:35 pm
content: I once had a laptop battery for a Hi-Grade Pentium 4 that use to attempt charging but cut out and every time that happened it had a varnish smell.

author: cdev
author_rank: Super Contributor
timestamp: November 24, 2018, 02:23:33 am
content: Is this the Acer "Expire"?

author: amyk
author_rank: Super Contributor
timestamp: November 24, 2018, 02:44:22 am
content: Quote from: bd139 on November 23, 2018, 07:56:24 amPuncturing a cell isn't the problem, shorting it out is. They're not pyrophoric.He might've actually shorted the two terminals together too, looking at the video closely.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 24, 2018, 08:51:12 am
content: Any even remotely decent cell is fine with a short. Or not fine, they will definitely die, may vent pressure or release a bit of smoke, but they should never go up in flames due to external short, and not produce enough heat to set the neighbor cells in thermal runaway. It's the most basic protection implemented at the cell level. Only the worst offenders go up in flames due to an external short.Puncturing is harder to deal with on cell design because it creates distributed internal shorts, bypassing any simple fusing. The separator design must really work to shut down ion transfer in time at each location that's running away. Nowadays, good cellstendto deal with punctures fairly well.Large multi-cell packs in dense 2D matrices are always problematic, since the cell level protections are tested and reported by the manufacturers with a single isolated cell.

author: bd139
author_rank: Super Contributor
timestamp: November 24, 2018, 09:50:04 am
content: Quote from: amyk on November 24, 2018, 02:44:22 amWhen you puncture it you short it usually.

author: GlennSprigg
author_rank: Super Contributor
timestamp: November 24, 2018, 11:42:40 am
content: Quote from: Siwastaja on November 23, 2018, 07:28:26 am(Thank you to 'blueskull' too, for his additional answer...)'Siwastaja' ... Thank you VERY much for your in-depth and very informative response !!I now understand a lot more !!