iFixit stabs batteries – for science – so you don't have to
- Reference: 1668792673
- News link: https://www.theregister.co.uk/2022/11/18/ifixit_stabs_batteries_for_science/
- Source link:
Tech writer team lead Arthur Shi and teardown techie Shahram Mokhtari from the DIY electronics repair site [1]got together to stab some iPhones and laptop batteries, and even shot a giant battery with a nail gun – all for science, of course.
[2]Youtube Video
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The pair's objective wasn't only to show how awesome shots of batteries exploding in slow motion looks, but also to demonstrate what they said is a key part of staying safe when working around lithium-ion polymer (li-po) batteries: their charge level.
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"The batteries in our electronics tend to [6]grab headlines when they go awry, but the truth is those are extreme edge cases," Mokhtari said.
Why li-po batteries go bust
If you're not familiar with the makeup of a lithium-polymer battery, Shi's explanation in the video breaks it down pretty plainly. Think of it like a fruit rollup, packaged tightly in its cellophane plastic wrapper to keep the layers from sticking together.
A single li-po cell is like a wrapped fruit roll that's filled with an electrolyte slurry, and a thin separator sits between the positive cathode and negative anode to prevent them from touching and causing a short circuit.
The typical li-po fire is caused when a battery is punctured or damaged in such a way that the separator is damaged, causing a short circuit. With enough energy contained in the battery, the flammable vapors caused by the decomposition of battery electrolytes can be heated to the point they explode, leading to thermal runaway that can burn for hours, depending on the size of the battery and damage.
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As li-po batteries age, the chemical reaction that supplies power can degrade, leading to the creation of gasses that cause swelling. While swollen batteries are hazardous, the iFixit team [8]said that even when swollen, a battery won't explode if discharged.
[9]Those screws on the Apple Watch Ultra are a red herring
[10]Teardown shows Apple iPhone 14 Pro is not pro-repair
[11]iPhone 14 iFixit teardown shows Apple's learning on repairs
[12]Apple adds M1 Mac notebooks to self-repair scheme
To demonstrate how batteries at different charge levels explode or don't, Shi and Mokhtari stabbed an [13]iPhone 12 Pro Max with a fully charged battery and one discharged to 25 percent. When punctured with a metal tool, the results were radically different.
The battery charged to 25 percent smoked and emitted some sparks, but never caught fire because there wasn't enough energy in the battery to lead to thermal runaway. The full one, on the other hand, was more than happy to go up in flames.
Stopping thermal runaway
Techies working on lithium-ion devices should take some basic precautions, iFixit said, like the aforementioned discharging of batteries to 25 percent before beginning repairs. Batteries should also be the first thing disconnected and last reconnected.
It's also ideal to use plastic tools whenever possible. Shi and Mokhtari demonstrated stabbing an iPhone battery with a plastic spudger, which damaged the battery but didn't cause any smoke or damage as the plastic reduces the chance for a puncture to cause a spark.
One final word of warning from the pair was to do with the handling of large li-po batteries, like those in laptops and larger hardware. Even when discharged to 25 percent, such batteries can still contain enough potential energy to cause combustion. For safety, discharge larger batteries completely, but recharge them as soon as repairs are complete to prevent damage.
And it goes without saying, but don't shoot a battery with a nail gun, regardless of its size. ®
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[1] https://www.youtube.com/watch?v=jGUkKi7cfK4
[2] https://www.youtube.com/watch?v=jGUkKi7cfK4
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/personaltech&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2Y3gOhz8JtfAKhzHFuDKAvQAAAI0&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/personaltech&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Y3gOhz8JtfAKhzHFuDKAvQAAAI0&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/personaltech&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Y3gOhz8JtfAKhzHFuDKAvQAAAI0&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[6] https://www.theregister.com/2019/08/07/surface_bulging_batteries_and_borked_firmware/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/personaltech&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Y3gOhz8JtfAKhzHFuDKAvQAAAI0&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://www.ifixit.com/News/69041/how-batteries-can-catch-fire-and-how-to-prevent-it
[9] https://www.theregister.com/2022/09/28/apple_watch_ultra_repairability/
[10] https://www.theregister.com/2022/09/27/apple_iphone_14_pro_repairs/
[11] https://www.theregister.com/2022/09/19/iphone_14s_ifixit/
[12] https://www.theregister.com/2022/08/22/m1_macs_self_repair/
[13] https://www.theregister.com/2017/10/06/apple_iphone_8_plus_batteries_swell/
[14] https://whitepapers.theregister.com/
Re: Fruit Rollup?
Try "Swiss roll" - a structure of several distinct layers rolled up into a cylinder.
Re: Fruit Rollup?
Jam Roly Poly?
Interesting video
Now, can we get back to the Good Ol' Days TM where you could replace the battery in your "smart"phone ?
Re: Interesting video
I've had that happen while repairing my co-workers phone, I was able to pull the battery out and throw it through the door into the parking lot and then it was easy to put a new one into the phone, it's still working.
Fly on a plane and they will tell you not to readjust your seat if you had dropped your phone ... we've heard of that issues a few times on planes and occasionally we hear about the trash pickup vehicle catching fire when it "packs" the trash pickup contends, maybe someone left a phone in an old jacket pocket in the trash?
Re: Interesting video
Disposable vapes are notorious for this, especially if you get an early failure. They mostly use li-po packs... (yes, rechargeable despite being one time use devices, the cells are cheaper). Garbage/refuse collection truck fires are getting more common
Yawn ...
The video might be fun but there's nothing new (or even exclusive to Lipo) in the information. Furthermore, the idea that there's a magic "25% charge" safety level is a hazardous one. The general golden rule for safety has always been " remove the power source before working on the kit ". This applies to everything electrical from a mains hair drier to a pocket calculator and everything in between. But if the battery is glued into your phone (dumb move) don't take chances.
Energy has to go somewhere
Ever disassemble something with a compressed spring, inadvertently set fire to flammable materials, be it fuel or food? Stored energy needs to be respected. As a kid I scraped out the fuel from a model rocket and got the match about 6 inches from the powder pile before a flash of heat and light passed my face, luckily with no lasting ill effect other than a greater appreciation for stored energy.
Re: Energy has to go somewhere
Energy doesn't HAVE to go somewhere. There are designs for solid state lithium batteries that can be stabbed repeatedly and not only not blow up or catch on fire, but continue operating (at a reduced capacity) but the trick is making them keep the other characteristics of their more flammable cousins from capacity to charge time to manufacturing cost. It is being worked on, but unfortunately they aren't there yet.
Re: Energy has to go somewhere
Yeah - one of my early jobs was as a trainee TV repair technician. Working with Cathode Ray Tubes taught you to respect that 12-15kV (black and white TVs) and up to 26kV for colour TVs.
One senior technician once got zapped with around 25kV between his little finger and his wrist. The muscle between the two stood to attention for several long minutes and he was feeling a tad unwell for a couple of hours afterwards. He certainly didn't do THAT again in a hurry! As this was back in the early 1970s I'm not even sure if we had proper accident report books back then. It was just one of the hazards of the job though it was drilled into us that you NEVER had both hands inside the back of a live TV while fault finding.
Hmmm
That big battery looks a lot like the ones that go in small UPS's. At least the APC UPS's I've had. But, I'm not worried because I'm pretty sure that APC only uses lead-acid batteries (like old car batteries), which don't have the same problems.
Re: Hmmm
I don't think that was a lead-acid battery, because there's nothing in lead-acid batteries that's very flammable. Damage to lead-acid batteries can cause a huge surge of current if the battery shorts out, and that can be very destructive, but they don't tend to burst into flame like lithium batteries can.
Re: Hmmm
Isn't there a mild hydrogen kaboom issue when they're active?
Re: Hmmm
No, but the battery can burst due to gas release, and spray sulphuric acid around. Could be worse than a fire.
Re: Hmmm
Yes. If you over-charge a lead-acid battery, it can start to electrolyse the water in the electrolyte (which is relatively dilute sulfuric* acid), producing hydrogen at the cathode, and oxygen at the anode. If the cell is sealed, the gas will build up pressure unless vented, either by design or by something splitting/breaking. This is why large UPS installations are well ventilated/vented** (and I think building codes in some places require panels designed to easily blow out without fundamental structural damage) - because a build up of hydrogen in an enclosed area has a non-zero risk of generating an unexpected explosion.
*No, this isn't isn't a manifestation of The Register house-style; [1]IUPAC naming rules are that sulfur is written with an f , not ph .
** [2]HSE Guidance (PDF)
[1] https://www.nature.com/articles/nchem.301
[2] https://www.hse.gov.uk/pubns/indg139.pdf
Re: Hmmm
Nope. I had an IBM-rebranded APC with 4 of the standard 12v lead acid batteries inside.
I came home to a "funny smell" and smoke venting from a mostly melted plastic case. IBM paid for me to ship it to them and sent a FedEx pickup to my house with a special shipping container.
There was a nice big scorched spot in the carpet and I'm still using the desk with the scorch on the side.
100% is playing it safe
The rated capacity of a LiPo is for electrical storage but it's not yet at full energy capacity. Charge it with no protection circuit. There's no heat, no puffing, just soaking up the charge. The true 100% is revealed when the battery suddenly explodes and the metal plates burn.
(I've read that this is lithium electrolysis - a very bad thing)
One thing that was totally glossed over
So nobody is going to mention how they hit the large battery fire with a full extinguisher blast and it didn't even faze it?
Which I expected, but nobody made the point that lithium fires don't go out until they burn everything.
Re: One thing that was totally glossed over
Single pouch cells extinguish easily as long as they weren't overcharged. You're thinking of multi-cell packs where thermal runaway hops from cell to cell for potentially days.
Fruit Rollup?
Can we have that in English?