While I definitely approve this and consider the limit to be one too many, I wish ecigarettes would be rather the target as soon as possible. Those are dangerous, and lately the most potential culprit for lithium related problems aboard.
It's not even just a QA thing, consider the use case: A sub-ohm vape head is basically almost shorting what is often a unprotected lithium ion cell (18650 or whatnot). Phones meanwhile are full of temperature sensors, battery pack in the phone has some kind of firmware/monitoring, board on the phone has a charge controller.
There are plenty of good cell manufacturers that won't have problems in this current dumping situation (and will have certain passive protections like a CID to cut the current if it gets too hot). Problem is people like cheap and there are sketchy knockoff cells without those protections and shoddy manufacturing quality.
If there was anything recently that forced the change it was probably the CT scans of the Haribo battery packs showing the cathode/anode overlap. This sort of thing should spook airlines.
Do we still have UL? Do they test battery packs? Why not make it a requirement to only fly with ones that pass lab testing like UL?
Phones, tablets, and laptops are not sold in bodegas, designed to be disposable, and thus made as incredibly cheaply as possible.
The high end vapes use huge amounts of current to the point that vape users will specifically seek unprotected cells because the protection circuitry adds a slight bit of internal resistance.
So then the unprotected cells can then short out in their bags or otherwise be damaged and fail when the vape electronics fail...
I think many don't appreciate just how horrifically cheap and dangerous some of this stuff is. Not just vapes, but things like charging bricks too.
I'm generally not a proponent of draconian regulation but I firmly believe that any electronics handling substantial voltage not approved by UL or similar should be rejected at the border. It's all dangerous and incentive to manufacture it needs to be curbed.
E cigarettes work by shorting the battery releasing a lot of instantenous heat. Their safety controller firmware are often of ... Dubious quality. It can happen quite often that the cigarette doesn't stop shorting the battery and catch fire as a result.
Making fire is literally their function unlike a laptop.
Combine that with basically unregulated and semi illegal supply chain and it becomes a recipe for disaster
AFAIK that's not really true, at least of modern vapes. Their function is not to "make fire", it's to heat a metal coil to a specific temperature at which propylene glycol and vegetable glycerin will aerosolize which is far lower than ignition temperature. Most modern vapes also use controllers with a feedback loop that pulse power through the coil hundreds of times per second to maintain the ideal temperature and desired power throughput. That being said there are definitely crappy and diy devices that unsafely dump huge current through devices but AFAIK modern devices generally don't do this because it's a bad user experience (burnt taste, too hot, ruined cotton absorber, etc) -- regulating the power is what users want so it's what devices do.
On recent WestJet flights they announced that you can't use a power bank if there is seat power available, all the flights had seat power except the smallest plane (Dash 8) and that flight was only 18 minutes. They also didn't want any batter powered devices in the overhead compartments.
On the 737s there were only two plugs per 3 seats so not everyone could be plugged in.
Many airlines are going much further than this, for instance Virgin Atlantic ban you from either charging or charging from any power bank, and you can't keep them in the overhead locker, you must keep them next to you in case it starts burning spontaneously!
They have a "fire containment bag" they can chuck it in should you notice it getting hot or smoking.
I flew Cathay Pacific late January and power banks were prohibited in both checked luggage and overhead bins. Of course the overhead bin restriction would have been difficult to police and enforce. Also prohibited to use them for charging devices or to be charged from the onboard USB outlets. But the onboard outlets were good enough for anything I needed to do during the 15+ hour flight.
> of course the overhead bin restriction would have been difficult to police and enforce.
In China (Mainland of course), they will toss your powerbank at security if it isn't approved, and the approval they are using is rather recent and Chinese specific, thankfully most recent powerbanks made in China have the approval. They are very efficient in snuffing out powerbanks also, their thoroughness would definitely make our TSA blush.
> But the onboard outlets were good enough for anything I needed to do during the 15+ hour flight.
Coincidentally, I just checked in early for an upcoming Air Asia flight (first time on this airline, not China) and see that among other restrictions they require power banks to "be carried on your person or in the seat pocket in front of you" and "sealed in a plastic or insulated pouch or kept in their original retail packaging to prevent short circuits".
Crazy thing about these bags is that they're just containment. Once the thermal runaway has started, it's very hard to start as it brings its own oxygen, heat and fuel.
Hence why many places bring a container filled with water to extinguish an EV fire, and then probably send it to a wet shredder to make sure it doesn't re-ignite.
My company distributed buckets filled with cat litter for containment to every branch office.
We cut the rate of fire (already low) in half by containing compromised batteries. It’s something like 0.02%-0.03% which is significant given the massive scope. Something like 200k devices and about 3% with battery issues of all types.
When you think about the number of flights, passengers with lithium batters and challenges of the airplane environment, it’s a hard problem. We’re lucky the engineering around these devices are as good as it is.
Kitty litter is not a bad choice for a class D metal fire but make sure you have the correct type. You want the stuff made out of bentonite clay, not the stuff made out of grain byproducts.
Sorry i should have been more precise. It's some sort of enterprise kitty litter, which is probably the material you reference and costs about 5x kitty litter. ;)
$500 million in clean-up costs resulting from using the wrong kitty litter. Amazing.
Sounds like the cleanup costs were largely related to the fact that the reaction caused an airtight drum to explode and spew radioactive waste throughout the facility, though, which presumably wouldn't apply to the "metal fire on an aircraft" scenario.
I'm curious what would actually happen, worst case.
Assuming the metal fire couldn't be extinguished, could it at least be contained to melt a small enough hole in the aircraft to safely land?
The scary thing about a class D fire is that it is self oxidizing. They are very hard/impossible to put out. Usually the best you can do is isolate it from anything else that can burn and let it burn itself out, if you have the space and equipment and correct environment you can try and break it up, but that is a lot of ifs. Water can be problematic because there is a good chance it will just scatter a bunch flaming goo everywhere not put anything out. Usually the best thing to do is to stick it in a bucket of sand. Second best is to dump sand on it. Clay type kitty litter would be a good substitute for sand, it won't catch on fire, lighter than sand, it will absorb any molten residue from the fire.
My guess on the plane scenario, there are enough secondary effects (smoke, insulation/trim/carpet/seats catching on fire) that would bring down the plane. but I don't think a personal battery has enough fuel to burn thru. I think the isolation bags are probably just aluminum(perhaps steel) foil. enough layers to let the infernal thing burn out without catching anything else on fire. You probably still get a lot of nasty smoke.
I am pretty much sacred by amount of stuff I have at home that does have lithium batteries.
I try not to keep any in drawers but possibly in one open place and having fire blanket close to that stand.
Fire blanket would not help much for thermal runaway but I guess it would be better than nothing for containment or at least getting that one away from all the other batteries so they don’t chain react.
We had an incident where a laptop with a swollen battery fell and lit up in a public way. It attracted attention and some research was done - they realized it happened a dozen times a year. Hazardous disposal options vary by location. So the question became… what should be done with these compromised batteries before they get disposed of?
It’s a simple thing that costs nothing. It’s like a fire extinguisher to me - I’ve never experienced a fire at work, yet we have extinguishers and exit signage everywhere.
That said, the rate of burning batteries is very low. (Like 0.001%) Unless you have a ton of people and different use profiles, you’ll never see this happen.
The common clumping litters are usually some form of clay, dried to remove moisture. It's about as nonflammable as things come and lighter than undried clay.
I am going to ask a question that I’m a little scared to ask because I suspect it’s really dumb, but here goes: is it at all feasible or practical to have a way to jettison a runaway battery from the aircraft? I guess most of the time the problems happen because nobody knows there’s a problem before it’s gotten too out of control for that.
You’d have to devise some sort of fire proof mini airlock, large enough for a laptop or whatever the largest device you expect to deal with. This would be pretty expensive and not very practical, but even if it was, then you’d have to deal with the ethical and legal issues of where it lands and whether or not it might cause a fire there too, to say nothing of injuring someone or damaging property.
Sure, I wasn’t trying to imply that it couldn’t be done, only that it would be expensive and impractical for civilian aviation, especially when there are good alternatives.
Interesting... anyone know if they've released the rationale/data behind this? I could see a few reasons why power banks present a larger risk than phones/computers (battery capacity, quality control), but it seems like the 100Wh battery limit already covers one of these.
In a similar vein, China banned non-CCC certified (the equivalent to UL or CE) power banks on flights from 2025, which seems to be targeting the quality control side of the problem. Not just on paper - the security officers inspected every lithium battery I was carrying, even the one in my flashlight.
> While data indicated that portable electronic devices were more often the cause of fire in aircraft cabins than power banks were, the latter were a significant concern due to their increased use and a prevalence of lower-quality products with defects or vulnerabilities that were more likely to lead to thermal events. Power banks were also not offered the same level of protection that batteries installed in portable electronic devices were provided. The amendments therefore focused on power banks.
Another possibility is that you tend to keep an eye on where your phone and laptop are; there have been some plane fires where people drop a phone into a seat and it ends up getting bent, but at least they notice it fairly quickly.
(Will people know the direction if their USB-C power bank is charging from their phone or their phone is charging from their power bank?)
Look up Air Busan Flight 391, a power bank in someone's carryon caused the entire plane to burn down in 5 minutes. The airplane (an Airbus A321) was destroyed. The only reason there was not total loss of life was because the plane hadn't taken off yet.
This could happen with any battery-powered device though. But I don't see ICAO or FAA banning e.g. laptops any time soon, even though they may carry more energy than a single power bank.
Phones tend to be designed by companies competent enough to design a phone. There's a skill floor required that just doesn't exist for power banks.
Another reason is that phones get replaced more frequently, whereas a power bank will be continually used essentially until failure. I only stopped using my last power bank because it puffed up like a balloon.
But yes, probably where this is all headed is that some day in-seat power will be banned so that you can only discharge and not charge your devices.
It seems to me that compared to your phone, a power brick dangling off a charging cable is much more likely to slip off your lap unnoticed and get wedged in the seat hinge only to get subsequently punctured.
I recently took a flight where I had a laptop, my phone, a power brick, a new power brick for my wife, a second phone (for reasons) and a battery for a piece of ham radio equipment in my backpack. As I got on the plane, I was thinking I was probably one of the risker passengers on board :) Anyway, when I use the brick, I keep it zipped in a jacket pocket with just the charing cable coming out in an effort to keep it from finding its way to a place that it shouldn't.
> I could see a few reasons why power banks present a larger risk than phones/computers (battery capacity, quality control), but it seems like the 100Wh battery limit already covers one of these.
Yeah, and it's the other one that is the main problem. It is simply impossible to know the quality of a power bank by looking at it.
> China banned non-CCC certified (the equivalent to UL or CE)
And it costs nothing to stamp the logo as if you're certified without actually going through any certification. Powerbanks are almost expendable, and can be acquried from supermarkets, corner shops, airports, even night clubs. There are even disposable ones (horrible idea). The more complex and expensive the device (like a laptop), the more certain can you be that there will be at least some quality control. In a $5/5eur powerbank, which any one could potentially be, it's almost guaranteeed there would be none.
> One deterrent is, in China corporate criminals are executed, like those who put melamine in infant formula.
At least in that case, no corporate executives were executed (I was living in China at the time so followed the case closely):
Those Executed:
Zhang Yujun: A farmer convicted of producing and selling over 770 tons of melamine-laced "protein powder" to dairy wholesalers.
Geng Jinping: A milk collection center manager who added the toxic powder to fresh milk before selling it to major dairies like the Sanlu Group.
Corporate Executives: The highest-ranking executive involved, Tian Wenhua (former chairwoman of Sanlu Group), was sentenced to life imprisonment rather than death. Other executives received prison terms ranging from 5 to 15 years.
Other Penalties: A third man, Gao Junjie, received a suspended death sentence (which typically commutes to life in prison), and several others received life sentences or long-term imprisonment.
Not really worried about the Chinese. As was pointed out, they just hang a sword of damocles over the head of every entrepreneur and engineer who even thinks about doing something like that.
What about power banks from India? Vietnam? Malaysia? Korea?
That's what I'm saying. If there are nations where you can get away with it, then those power banks can end up in Western, African or South American markets.
(I'm counting getting a fine, or paying a bribe, as getting away with it. I don't really consider those punishments that will provide sufficient deterrent.)
> What about power banks from India? Vietnam? Malaysia? Korea?
90% of powerbanks made are from mainland china. Worrying about powerbanks made outside of China is like worrying about guns made outside of the USA, theoretically possible, but those countries are so dominant and efficient in those fields that it is more of a "what if" rather than a real concern.
I bring a single high-quality large power bank whenever I travel. It's hard to reliably find power for my phone, laptop, e-reader, earbuds, gamma spectrometer, flashlight, etc while in the airport or in flight. Not every plane I end up on has reliable USB chargers. Sometimes it's handy to just plug my devices in while they're in my bag.
Airlines are doing this new fun trick where they interrupt your in-flight entertainment not only for the safety announcements, but also to play ads for their credit cards. And they'll turn up the brightness if it's turned down and turn up the volume if it's too low.
I do tend to mostly read on planes, but e-readers are nice because you can pack fifteen books into something the size of a couple of phones, and they can be backlit so you don't have to annoy your neighbor when they're trying to sleep. Back in the day I always had the problem of putting like three library books into my backpack and more into my checked bag, but I'd still finish them all before the return trip was over and be left without anything to read. With e-readers, I can check out new books mid trip, or even at the airport.
New planes don't have screens, they may have free wifi to watch stuff on your device. Of the 6 planes I have been on in the last two weeks only one had screens. Just back from vacation :)
I'm not one that he flies with gamma spectrometer. But I've had RadiaCode 103G since Dec 2024. It's pretty neat device that can be brought with you almost anywhere.
It's made in Cyprus (EU) and has apparently received some EU funding. Using Google Search AI mode and asking what is CEO Sergey Shek connection with Moscow Radiological institute gave me following reply.
"The connection between Sergey Shek, the founder of Radiacode (formerly Radiascan), and Moscow's radiological research centers is primarily rooted in his and his team's professional and academic history.
The key points of connection are:
Academic and Professional Origins: Radiacode’s founding team consists of Russian physicists and engineers who were educated and began their careers at prestigious scientific institutions in Moscow. These include researchers formerly associated with the N.N. Semenov Federal Research Center for Chemical Physics and other centers specializing in nuclear physics and spectroscopy.
Early Product Development: The company's initial products, such as the Radiascan-701, were developed in Russia using the technical expertise gained at these Moscow-based institutes. The technology behind their current high-precision scintillation detectors stems from this scientific background.
Relocation and Independence: Following the start of the conflict in Ukraine, the company officially rebranded as Radiacode and shifted its headquarters and operations to Cyprus and the United Kingdom. Sergey Shek and the company have sought to distance themselves from Russian state institutions to operate as a global, independent entity.
Today, while the "scientific DNA" of the company originated in Moscow's radiological research environment, Radiacode operates entirely outside of Russia and focuses on the international market for hobbyists and professionals."
Russian background didn't sound good to me for obvious reasons. Thus I did not install app to my daily driver phone and use a separate Android device for this app. But the device is nice and app quite good for what I've used it.
Adding: You can find videos about the device from Youtube.com
Easier if you have a vast domestic flight market (US, China, etc), but not really practical if you're flying across borders, which is the base case in Europe, much of Asia, etc.
With traditional outlets you also inherit the whole legacy mess of competing standards for power mains. You don't want to feed 240V to a NEMA 1-15 outlet and melt someone's device mid-flight.
I do wonder if in some far future we'll just replace wall outlets with USBs for ordinary appliances, reserving traditional outlets for major power draws like stovetops, HVAC, industrial equipment etc. Maybe planes are the vanguard of this future?
So how do most European airlines have just that on their intercontinental flights?
I don't think I've flown intercontinental without universal power sockets (accepts EU & US plugs, sometimes others, voltage info hard to find) in the past 10 years.
In some cases it's sadly still a premium cabin thing. I refuse to fly economy at this point, premium eco tends to be good enough to get power sockets.
They exist but are insanely unsafe. It would be ten kinds of illegal to install a socket like that in your home under any code I've ever seen.
It's already difficult enough to prevent people from making contact with the live parts when you're dealing with a plug and socket actually designed for each other. There's no hope in hell when you have ten extra holes.
What are you going to plug into a power outlet on an airplane that isn't dual voltage? A kettle or a toaster? I assume they have a way of preventing people from using those.
Almost all the international flights I've flown have had power outlets, always between 220V and 110V countries (heck, only Japan is 110V besides the US as far as I know).
I it works for China because they use (as an option at least) similar outlets to the USA (just ungrounded, pop).
I think 'assuming that the airline has a way of preventing' people from plugging in dangerous items is doing a loooooot of heavy lifting in your argument.
How, exactly? The airlines have absolutely no way to know what shoddy electrical device you bought god-knows-where you're plugging into mains power in their airtight travel-coffin, packed with hundreds of people, hurtling across some ocean.
> Almost all the international flights I've flown have had power outlets
Seems deeply unusual to me, but I won't dispute your experiences. I've flown internationally fairly often, and in my experience power outlets are rather uncommon (at least in the eastern hemisphere, flights to/from the Americas may differ, I haven't flown around there for many years).
Central/South America has a lot of 100-130 V too, I believe, but I don't have direct personal experience.
I find the standard voltages pretty interesting. The 230 V standard, for example, is mostly a lie. In reality, Britain and former British colonies tend to run on 240 V, and continental Europe/Asia/Africa tends to run on 220 V. The 230 V standard includes wide enough tolerances so that no one needed to actually change anything. I've never actually seen 230 V, the supposed standard, in real life.
Europe has a lowest common denominator plug, there are universal outlets (jack of all trades, master of none) that you already often find in airports, and each airline has a home country anyway.
Yeah, no. In EU+CH alone, you've got Schuko, French, reversed French (Czech), British (Ireland, Malta, Cyprus), and more rarely Italian, Danish and Swiss plugs. And those are just the current national standards as of 2026, ignoring anything non-standard or historic or foreign.
You can't just slap some ungrounded 240V Frankenstein multi-socket on the back of a plane seat and call it a day. Hell, you can't even do that in your own house in most developed countries.
That's before you even get to passengers plugging in their own $2 socket converters off eBay, half-inserted and loosely hanging off your already-lethal socket. And then these passengers wrap themselves in a synthetic blanket and go to sleep. What could go wrong.
We're not talking about some CRUD web app here, where being held together by sticky tape and prayer is fine and expected. This would actually kill people. Not exactly easy to deal with a smouldering corpse in the middle seat at 30,000 feet.
Fingers crossed the Donut Lab solid state battery ends up being the real deal, lives up to the hype, and this sillyness can finally go away. Recent tests look promising from a (lack of a) thermal runaway standpoint at least.
The only question is if the rules will mind the difference in battery composition and chemistry.
Most of the solid state batteries have far less thermal runaway problem than lithium-ion batteries. At this point, several companies have working demo solid state batteries, but the price is far too high. Mercedes has one demo car with a solid state battery. Ducati has one motorcycle.
Donut Labs just has one demo cell, not even enough for their motorcycle. The technology works but is so expensive there aren't even multiple prototypes.
Samsung says they will ship some solid state batteries in watches and earbuds this year, where the batteries are so tiny they're affordable. Even solid state batteries for phones are still too costly.
Everybody in the industry is trying to solve the production price problem.
Consensus is that the price starts to come down around 2028 or so.
Lithium iron phosphate batteries don't have a thermal runaway problem, either, but they have about half the Wh/Kg of lithium-ion, so they're not popular for portable devices.
Ten years out, lithium-ion batteries will probably be obsolete technology and totally prohibited on aircraft.
Donut Labs: "The Future of Powering Electric Vehicles Is Here Today with Donut Lab Introducing New High-Performance Solid State Donut Batteries Ready for OEM Use Now and Powering All 2026 Model Verge Motorcycles On the Road in Q1 2026."[1]
So wait if solid state is too expensive? What replaces lithium ion batteries? What breakthrough do you expect in solid state to make it cheaper in 2028?
Not the original poster, but I’m a fan, in appropriate applications. Robust, fast discharge, long cycle life, and can charge and discharge at lower temperatures than most other chemistries (-20C and -40C, for what I’m using). Downsides are limited availability and sizing, and absolute crap energy density even compared to LFP.
I have the 2.9 Ah SCiBs for form factor testing, and the 10 Ah Shenquans for some functional testing. I’m eagerly awaiting the 5.5 Ah SCiB — the application is designed around a 20S1P 5.5 Ah SCiB string.
Thank you. The moment these have reasonable pricing I'm ordering up enough to put together a 200 KWh home battery. It isn't quite economical yet but there is no way I'm putting such a quantity of Lithium-Ion in anything near or in a dwelling.
Most LTO cells are focused on bigger cells than what I need — 20 Ah to 100 Ah is much better covered than 5 to 10 Ah. Unfortunately aircraft are weight-critical.
I wasn't sure what a solid state battery is, so I looked it up on Wikipedia.
Fun fact though:
> Between 1831 and 1834, Michael Faraday discovered the solid electrolytes silver sulfide and lead(II) fluoride, which laid the foundation for solid-state ionics. Through his research, Michael Faraday took note of these solid compounds transitioning from insulators to conductors after being heated. While this would take almost another century to be acknowledged by Michael O'Keeffe in 1976, this mixed ionic/electronic conductions became the first record of a solid-state battery
Afaik sodium batteries are much safer than li-ion and already in mass production. Unless Donut scales up really quick I think it will be more viable to just use sodium batteries for safety in the medium-term future
We bought a sodium battery for our last trip, and it turns out that most airline companies don't even know what sodium batteries are and don't have any provision in their regulations, they are as restricted as lithium batteries :(
Aren't those just regular Li-ion with thickened electrolyte solution? There seem to be some noises around "almost solid" batteries pushing the definition of the word "solid".
The real production solid states are made with inorganic materials, many not in pouches nor cylinders, and has wild environmental resistance like supporting charges in -55 to +125C(-70 to +260F) which won't be possible with most water inside.
One of the recent high temp tests showed a degradation in capacity that is supposedly [0] strongly consistent with solid state tech. I'm not qualified to know better unfortunately.
I just use my laptop as a powerbank these days. What I typically need to charge is a phone, with way smaller capacity than my macbook. So it works pretty well now that everything has usbc.
Limiting the devices to two per person seems nonsensical to me. The devices are either dangerous, or they're not. If they're dangerous, two is too many. And if they're not, then why limit them only to two?
> The devices are either dangerous, or they're not
That's not actually how it works though, it's all a risk and percentages. Nobody says "driving is either safe or it's not" or "delivering a baby is either safe or it's not"
Correct, but I agree with the parent that this is a dubious case to apply that reasoning.
To make it clearer, imagine another context: "It's dangerous for a passenger to have a gun on board. Therefore, we're strictly limiting passengers to only two guns."
Like, no. The relevant sad case is present with one gun just as with two.
Of course, what complicates it is that these power banks present a small but relevant risk of burning and killing everyone on board. So yeah, you might be below the risk threshold if everyone brought two, but not three. So it's not inherently a stupid idea, but requires a really precise risk calculation to justify that figure.
That's not really how risk is managed in aviation. ICAO will have made a list of all possible ways a power bank could create a hazard. Then for each failure mode, they'll come up with two numbers: probability, and severity. There's a formula to combine those two numbers into a single risk score. Any risks over the acceptable threshold (varies depending on the circumstances and I can't remember what it is for human-rated transport) must be mitigated.
A mitigation is anything that reduces the probability or the severity of a risk. There are different categories of mitigation, some of which are more robust than others. Once the risk score moves below the acceptable threshold, the risk is satisfactorily mitigated.
Example: Rapid depressurization. Without mitigation, the risk of rapid depressurization is unacceptably high. So we mitigate the probability by requiring sensitive inspections for metal fatigue, and we mitigate the severity by providing oxygen masks, a standard flight crew procedure for making an emergency descent, and regular training on that procedure. (Plus a bunch of other things I'm not thinking of off the top of my head.)
Assuming ICAO did their due diligence - and I don't have any reason to think they didn't - they would've assessed the probability and severity of all of the ways a consumer power bank might fail. That analysis is the rationale for both the number of power banks allowed on a flight and what you're allowed to do with them. And yes, they will have considered the probability of people not following the rules (which is the reason, btw, that airplane lavatories have enormous "no smoking" signs right above an ash tray).
This is the first decent answer, which I appreciate. And while my comparison to a bomb may have been over the top, I don't think a comparison to shampoo is fair either. And in any case, I'm not so sure whether the limit on toiletries is all that sensical either.
These items are dangerous. The FAA limit for power bank capacity is 100Wh (~27000mAh), which is 360kJ of energy. A hand grenade has approximately 700-800 kJ of energy.
Two powerbanks contain the same amount of energy as a hand grenade.
That's a kind of meaningless comparison. Peanuts are about 8kJ per gram supposedly, by your measure we should ban even small amounts of peanuts on planes because 100 grams of them contain more energy than a hand grenade. Without talking about the time frame over which the energy can be released you'd have to make sure that everybody went onto the plane completely naked lest their clothes ignited.
Not good enough, body fat contains about 35kJ per gram. So nobody with over 1lb of excess body should be allowed on board. People are known to occasionally spontaneously combust.
More batteries, more likely that you'll have even just one of them fail. Since even one of them (to your point) failing is enough of a reason to divert the flight, better to start by reducing the probability of that happening in ways people can swallow.
So having 500 batteries on board is okay.. but 750 is too risky? I just have a hard time believing that the math is actually mathing in this case. Maybe you're right, and this is just a first step to get people to gradually accept more restrictions.
Maybe there is enough plane onboard capacity to deal with just 50 batteries, let's say; multiply the failure rate expected and the pax capacity of the plane and you get how many batteries you can afford to have onboard and still be able to deal with worst case scenario.
Do you save your snark for batteries only, or are you equally liberally minded with your non-binary thinking about the number of bombs allowed on board?
It's not fallacious, it focuses the issue, and in this particular case shows that it's not about "binary thinking" it's about risk.
And my original puzzlement continues. At what level of risk, does limiting the number of devices on board to 500 or even more, actually accomplish anything?
If they're not all that dangerous, then why limit them at all? And if they're dangerous enough to limit at all, why in God's blue sky, would you allow that many of them on a plane?
We don't limit people to 1 knife per person, even though knives have utility to a lot of people who carry one with them every day.
Because it's a numbers game... the original order itself even acknowledges that the problem is not unique to power banks, but that what makes power banks unique is the amount of increased risk they pose compared to other devices, due to a higher ubiquity of them in general, and of low-quality unsafe ones.
If laptops were catching fire with the same frequency, they'd ban those too, but they're not. They technically can be made just as unsafe as power banks, but they usually aren't, and this directive is based on the frequency of occurrence of a particular type of device, not a general "what if" strategy.
Banning all electronic devices would be extremely unpopular and possibly tank their sales. They're trying to balance safety with convenience at a level that is acceptable to most people.
If there are 20 battery banks on board a plane, each possessed by a different person:
* Less likely to be of the same low quality
* Less likely to all go off
* Less likely that someone is doing something malicious/suspicious with it
vs. someone who has 20 power banks themselves in a bag, in which case if one of them catches fire unexpectedly, they will probably all go up at once and create a cumulative effect much more dangerous than 20 individuals.
Content nonwithstanding, announcing rule changes like this with immediately taking effect is just shoddy practice. At least give travellers a few weeks of heads-up.
Some airlines and/or local aviation authorities have additional restrictions. China wants CCC certified power banks, Thailand has a strict 160 Wh limit. Both are very strictly enforced.
Power banks were a mistake. It's akin to carrying fireworks in your bag. Ban them all from air travel.
Every one I have owned has been recalled for being a fire hazard. EVERY SINGLE ONE. I stopped buying them as a result. We're talking name brand devices, not junk off AliExpress.
I've never had any issues with brand name, not dollar store power banks and I've been using them for more than a decade. I'd totally expect a $5 pink power bank from a alphabet amazon seller to be an issue, but anything modern and reasonable like Anker are very unlikely to cause you any issues. Balancing, protection are very much solved issues at this point for the cell chemistries we use.
If LiPo was the issue, using LiFePo4 or LTO cells for planes would be a totally reasonable alternative too. LTO cells are so safe the manufacturer of them has videos on youtube of them hammering nails into the cells, cutting them with a saw, and crushing them with a press and they don't really care.
That's a bit surprising to me, wonder what the root cause of that was. It seems to be shared across multiple products at once so maybe they had a bad batch of cells?
I'm sure people do. People will buy the absolute shittiest things to save a buck. The power bank could come with a skull and crossbones painted on it, and have the product name "Deadly Explosive Power Bank" and people would still buy it if it was $10 cheaper than a reputable one.
It's great technology, but sadly humans are fucking morons, and dodgy manufacturers making explosive power banks has lead to the restrictions...
Although honestly how bad is it, powerbanks are very popular, I can imagine in some regions there'd be hundreds of flights taking off daily with 150+ power banks on board (the majority of passengers on a 737), and they've all landed safely.
In my city, I could scan a QR code and pay the parking meter that way. Now they've decomissioned this and you have to go to the app and select the section of the road you're parked at. Why, because scammers made scammy QR codes. Great tech, can't have them because humanity's inherent scumbaggery.
Phone batteries are typically smaller (less energy which can be violently dissipated) than most power banks.
Naturally you will ask, what about tablets and laptops? They are prohibited from checked luggage for this reason. Power banks however are smaller and easier to conceal.
The risk is really in a fire developing in your bag down below in cargo, where no one can see it. By the time the fire alarms go off, it's too late and good luck if you are over water or the Arctic. If it happens upstairs they can at least tend to it with a fire extinguisher or bag/blanket.
See ValuJet Flight 592, fire in an airplane's cargo hold is probably one of the scariest ways to slowly die.
It's all about corralling risk. You can't tell people they can't bring their laptops. But power banks are unnecessary nice-to-haves.
Laptops, at least in the US, are not banned in checked luggage[1]. The airlines may have different rules, but generally the airline is not the one inspecting your bag, TSA is.
Ah, good. We're currently reliant on unpaid, probably-not-too-happy workers for fire safety. Sounds like a great time to stay off an airplane in the USA.
And that itself is a recent policy change from just in the last two months; as of January United's official policy [1] matched the FAA's in only requiring checked devices to be powered down
Li-ion fires do not require external oxygen, the cathode decomposes to release its own oxygen gas during thermal runaway... fire extinguishers will not stop it.
“Spare batteries, including power banks:
must not be recharged on board the aircraft;
should not be used to charge portable electronic devices on board the aircraft;
the number carried is limited to a maximum of two per person.”
While I definitely approve this and consider the limit to be one too many, I wish ecigarettes would be rather the target as soon as possible. Those are dangerous, and lately the most potential culprit for lithium related problems aboard.
There are plenty of good cell manufacturers that won't have problems in this current dumping situation (and will have certain passive protections like a CID to cut the current if it gets too hot). Problem is people like cheap and there are sketchy knockoff cells without those protections and shoddy manufacturing quality.
If there was anything recently that forced the change it was probably the CT scans of the Haribo battery packs showing the cathode/anode overlap. This sort of thing should spook airlines.
Do we still have UL? Do they test battery packs? Why not make it a requirement to only fly with ones that pass lab testing like UL?
> If there was anything recently that forced the change it was probably the CT scans of the Haribo battery packs showing the cathode/anode overlap.
It seems to be this, and yeah, it seems actually bad:
https://www.theverge.com/news/818906/haribo-gummy-bear-power...
The high end vapes use huge amounts of current to the point that vape users will specifically seek unprotected cells because the protection circuitry adds a slight bit of internal resistance.
So then the unprotected cells can then short out in their bags or otherwise be damaged and fail when the vape electronics fail...
I'm generally not a proponent of draconian regulation but I firmly believe that any electronics handling substantial voltage not approved by UL or similar should be rejected at the border. It's all dangerous and incentive to manufacture it needs to be curbed.
Making fire is literally their function unlike a laptop.
Combine that with basically unregulated and semi illegal supply chain and it becomes a recipe for disaster
On the 737s there were only two plugs per 3 seats so not everyone could be plugged in.
I’m an average person and my shoulders and knees are all pushing against everything.
It's not charging a device during flight that's the issue.
They have a "fire containment bag" they can chuck it in should you notice it getting hot or smoking.
https://www.virginatlantic.com/en-US/help/articles/powerbank...
In China (Mainland of course), they will toss your powerbank at security if it isn't approved, and the approval they are using is rather recent and Chinese specific, thankfully most recent powerbanks made in China have the approval. They are very efficient in snuffing out powerbanks also, their thoroughness would definitely make our TSA blush.
> But the onboard outlets were good enough for anything I needed to do during the 15+ hour flight.
Only if those plugs are actually working....sigh.
Agree that China TSA equivalent > US TSA.
Hence why many places bring a container filled with water to extinguish an EV fire, and then probably send it to a wet shredder to make sure it doesn't re-ignite.
We cut the rate of fire (already low) in half by containing compromised batteries. It’s something like 0.02%-0.03% which is significant given the massive scope. Something like 200k devices and about 3% with battery issues of all types.
When you think about the number of flights, passengers with lithium batters and challenges of the airplane environment, it’s a hard problem. We’re lucky the engineering around these devices are as good as it is.
https://practical.engineering/blog/2025/4/15/when-kitty-litt...
Sounds like the cleanup costs were largely related to the fact that the reaction caused an airtight drum to explode and spew radioactive waste throughout the facility, though, which presumably wouldn't apply to the "metal fire on an aircraft" scenario.
I'm curious what would actually happen, worst case.
Assuming the metal fire couldn't be extinguished, could it at least be contained to melt a small enough hole in the aircraft to safely land?
My guess on the plane scenario, there are enough secondary effects (smoke, insulation/trim/carpet/seats catching on fire) that would bring down the plane. but I don't think a personal battery has enough fuel to burn thru. I think the isolation bags are probably just aluminum(perhaps steel) foil. enough layers to let the infernal thing burn out without catching anything else on fire. You probably still get a lot of nasty smoke.
I try not to keep any in drawers but possibly in one open place and having fire blanket close to that stand.
Fire blanket would not help much for thermal runaway but I guess it would be better than nothing for containment or at least getting that one away from all the other batteries so they don’t chain react.
We had an incident where a laptop with a swollen battery fell and lit up in a public way. It attracted attention and some research was done - they realized it happened a dozen times a year. Hazardous disposal options vary by location. So the question became… what should be done with these compromised batteries before they get disposed of?
It’s a simple thing that costs nothing. It’s like a fire extinguisher to me - I’ve never experienced a fire at work, yet we have extinguishers and exit signage everywhere.
That said, the rate of burning batteries is very low. (Like 0.001%) Unless you have a ton of people and different use profiles, you’ll never see this happen.
Maritime patrol aircraft like the P-8 already have such a system, for releasing sonobuoys and float-flares while at altitude.
So it's not a technical issue, more one of regulation and maintenance.
Meh, it's a risk reduction thing. Aircraft sometimes dump fuel too in emergencies: https://en.wikipedia.org/wiki/Fuel_dumping
Earth is covered with a lot of water too, if you could eject it... risk is approaching zero on dumping a flaming battery over ocean.
In a similar vein, China banned non-CCC certified (the equivalent to UL or CE) power banks on flights from 2025, which seems to be targeting the quality control side of the problem. Not just on paper - the security officers inspected every lithium battery I was carrying, even the one in my flashlight.
Paragraph 4.3.3:
> While data indicated that portable electronic devices were more often the cause of fire in aircraft cabins than power banks were, the latter were a significant concern due to their increased use and a prevalence of lower-quality products with defects or vulnerabilities that were more likely to lead to thermal events. Power banks were also not offered the same level of protection that batteries installed in portable electronic devices were provided. The amendments therefore focused on power banks.
https://en.wikipedia.org/wiki/Air_Busan_Flight_391
Another reason is that phones get replaced more frequently, whereas a power bank will be continually used essentially until failure. I only stopped using my last power bank because it puffed up like a balloon.
But yes, probably where this is all headed is that some day in-seat power will be banned so that you can only discharge and not charge your devices.
I recently took a flight where I had a laptop, my phone, a power brick, a new power brick for my wife, a second phone (for reasons) and a battery for a piece of ham radio equipment in my backpack. As I got on the plane, I was thinking I was probably one of the risker passengers on board :) Anyway, when I use the brick, I keep it zipped in a jacket pocket with just the charing cable coming out in an effort to keep it from finding its way to a place that it shouldn't.
that’s not fully true though, ROMOSS is the brand that sold power banks caught fire, however all of those were CCC certified.
Yeah, and it's the other one that is the main problem. It is simply impossible to know the quality of a power bank by looking at it.
> China banned non-CCC certified (the equivalent to UL or CE)
And it costs nothing to stamp the logo as if you're certified without actually going through any certification. Powerbanks are almost expendable, and can be acquried from supermarkets, corner shops, airports, even night clubs. There are even disposable ones (horrible idea). The more complex and expensive the device (like a laptop), the more certain can you be that there will be at least some quality control. In a $5/5eur powerbank, which any one could potentially be, it's almost guaranteeed there would be none.
At least in that case, no corporate executives were executed (I was living in China at the time so followed the case closely):
Those Executed:
Zhang Yujun: A farmer convicted of producing and selling over 770 tons of melamine-laced "protein powder" to dairy wholesalers.
Geng Jinping: A milk collection center manager who added the toxic powder to fresh milk before selling it to major dairies like the Sanlu Group.
Corporate Executives: The highest-ranking executive involved, Tian Wenhua (former chairwoman of Sanlu Group), was sentenced to life imprisonment rather than death. Other executives received prison terms ranging from 5 to 15 years.
Other Penalties: A third man, Gao Junjie, received a suspended death sentence (which typically commutes to life in prison), and several others received life sentences or long-term imprisonment.
What about the rest of us?
That kind of fraud is oftentimes only a fine in many other nations.
What about power banks from India? Vietnam? Malaysia? Korea?
That's what I'm saying. If there are nations where you can get away with it, then those power banks can end up in Western, African or South American markets.
(I'm counting getting a fine, or paying a bribe, as getting away with it. I don't really consider those punishments that will provide sufficient deterrent.)
90% of powerbanks made are from mainland china. Worrying about powerbanks made outside of China is like worrying about guns made outside of the USA, theoretically possible, but those countries are so dominant and efficient in those fields that it is more of a "what if" rather than a real concern.
I do tend to mostly read on planes, but e-readers are nice because you can pack fifteen books into something the size of a couple of phones, and they can be backlit so you don't have to annoy your neighbor when they're trying to sleep. Back in the day I always had the problem of putting like three library books into my backpack and more into my checked bag, but I'd still finish them all before the return trip was over and be left without anything to read. With e-readers, I can check out new books mid trip, or even at the airport.
https://radiacode.com/
It's made in Cyprus (EU) and has apparently received some EU funding. Using Google Search AI mode and asking what is CEO Sergey Shek connection with Moscow Radiological institute gave me following reply.
"The connection between Sergey Shek, the founder of Radiacode (formerly Radiascan), and Moscow's radiological research centers is primarily rooted in his and his team's professional and academic history. The key points of connection are:
Today, while the "scientific DNA" of the company originated in Moscow's radiological research environment, Radiacode operates entirely outside of Russia and focuses on the international market for hobbyists and professionals."Russian background didn't sound good to me for obvious reasons. Thus I did not install app to my daily driver phone and use a separate Android device for this app. But the device is nice and app quite good for what I've used it.
Adding: You can find videos about the device from Youtube.com
Easier if you have a vast domestic flight market (US, China, etc), but not really practical if you're flying across borders, which is the base case in Europe, much of Asia, etc.
With traditional outlets you also inherit the whole legacy mess of competing standards for power mains. You don't want to feed 240V to a NEMA 1-15 outlet and melt someone's device mid-flight.
I do wonder if in some far future we'll just replace wall outlets with USBs for ordinary appliances, reserving traditional outlets for major power draws like stovetops, HVAC, industrial equipment etc. Maybe planes are the vanguard of this future?
So how do most European airlines have just that on their intercontinental flights?
I don't think I've flown intercontinental without universal power sockets (accepts EU & US plugs, sometimes others, voltage info hard to find) in the past 10 years.
In some cases it's sadly still a premium cabin thing. I refuse to fly economy at this point, premium eco tends to be good enough to get power sockets.
E.g ANA: https://www.ana.co.jp/en/jp/guide/inflight/service/seat_plug...
Related Wikipedia page: https://en.wikipedia.org/wiki/EmPower_(aircraft_power_adapte...
It's already difficult enough to prevent people from making contact with the live parts when you're dealing with a plug and socket actually designed for each other. There's no hope in hell when you have ten extra holes.
Edit: oh man I needed to scroll down, about a million people told you that hah.
I'm kind of surprised by this. I have no idea how you would do this safely at scale.
Almost all the international flights I've flown have had power outlets, always between 220V and 110V countries (heck, only Japan is 110V besides the US as far as I know).
I it works for China because they use (as an option at least) similar outlets to the USA (just ungrounded, pop).
How, exactly? The airlines have absolutely no way to know what shoddy electrical device you bought god-knows-where you're plugging into mains power in their airtight travel-coffin, packed with hundreds of people, hurtling across some ocean.
> Almost all the international flights I've flown have had power outlets
Seems deeply unusual to me, but I won't dispute your experiences. I've flown internationally fairly often, and in my experience power outlets are rather uncommon (at least in the eastern hemisphere, flights to/from the Americas may differ, I haven't flown around there for many years).
Japan is an oddball by being 100V.
US is 120 and that extends pretty far south (and north).
https://en.wikipedia.org/wiki/Mains_electricity_by_country
I’m semi amazed motor vehicles are as standard as they are with 12V and the same socket worldwide. I guess the tobacco industry is a great unifier.
I find the standard voltages pretty interesting. The 230 V standard, for example, is mostly a lie. In reality, Britain and former British colonies tend to run on 240 V, and continental Europe/Asia/Africa tends to run on 220 V. The 230 V standard includes wide enough tolerances so that no one needed to actually change anything. I've never actually seen 230 V, the supposed standard, in real life.
You can't just slap some ungrounded 240V Frankenstein multi-socket on the back of a plane seat and call it a day. Hell, you can't even do that in your own house in most developed countries.
That's before you even get to passengers plugging in their own $2 socket converters off eBay, half-inserted and loosely hanging off your already-lethal socket. And then these passengers wrap themselves in a synthetic blanket and go to sleep. What could go wrong.
We're not talking about some CRUD web app here, where being held together by sticky tape and prayer is fine and expected. This would actually kill people. Not exactly easy to deal with a smouldering corpse in the middle seat at 30,000 feet.
The only question is if the rules will mind the difference in battery composition and chemistry.
Samsung says they will ship some solid state batteries in watches and earbuds this year, where the batteries are so tiny they're affordable. Even solid state batteries for phones are still too costly. Everybody in the industry is trying to solve the production price problem. Consensus is that the price starts to come down around 2028 or so.
Lithium iron phosphate batteries don't have a thermal runaway problem, either, but they have about half the Wh/Kg of lithium-ion, so they're not popular for portable devices.
Ten years out, lithium-ion batteries will probably be obsolete technology and totally prohibited on aircraft.
They sent in multiple cells for lab testing, but more importantly the second Donut demo was a motorcycle charging.
They have until Tuesday.
[1] https://www.donutlab.com/ces-battery-announcement/
Fun fact though:
> Between 1831 and 1834, Michael Faraday discovered the solid electrolytes silver sulfide and lead(II) fluoride, which laid the foundation for solid-state ionics. Through his research, Michael Faraday took note of these solid compounds transitioning from insulators to conductors after being heated. While this would take almost another century to be acknowledged by Michael O'Keeffe in 1976, this mixed ionic/electronic conductions became the first record of a solid-state battery
(emphasis mine)
The real production solid states are made with inorganic materials, many not in pouches nor cylinders, and has wild environmental resistance like supporting charges in -55 to +125C(-70 to +260F) which won't be possible with most water inside.
[0] https://youtu.be/vWwPySIm9tU?t=511
That's not actually how it works though, it's all a risk and percentages. Nobody says "driving is either safe or it's not" or "delivering a baby is either safe or it's not"
To make it clearer, imagine another context: "It's dangerous for a passenger to have a gun on board. Therefore, we're strictly limiting passengers to only two guns."
Like, no. The relevant sad case is present with one gun just as with two.
Of course, what complicates it is that these power banks present a small but relevant risk of burning and killing everyone on board. So yeah, you might be below the risk threshold if everyone brought two, but not three. So it's not inherently a stupid idea, but requires a really precise risk calculation to justify that figure.
A mitigation is anything that reduces the probability or the severity of a risk. There are different categories of mitigation, some of which are more robust than others. Once the risk score moves below the acceptable threshold, the risk is satisfactorily mitigated.
Example: Rapid depressurization. Without mitigation, the risk of rapid depressurization is unacceptably high. So we mitigate the probability by requiring sensitive inspections for metal fatigue, and we mitigate the severity by providing oxygen masks, a standard flight crew procedure for making an emergency descent, and regular training on that procedure. (Plus a bunch of other things I'm not thinking of off the top of my head.)
Assuming ICAO did their due diligence - and I don't have any reason to think they didn't - they would've assessed the probability and severity of all of the ways a consumer power bank might fail. That analysis is the rationale for both the number of power banks allowed on a flight and what you're allowed to do with them. And yes, they will have considered the probability of people not following the rules (which is the reason, btw, that airplane lavatories have enormous "no smoking" signs right above an ash tray).
I’m not sure what you mean; when I Ctrl+F “shampoo”, this is the only hit I see.
Someone bringing 150 "lipstick" single-cell promotional chargers -> bad
Someone bringing one phone and one laptop battery pack -> OK
If you are limited to two, you are probably not bringing anything that is near e-waste quality.
Two powerbanks contain the same amount of energy as a hand grenade.
What you're saying is equivalent to claiming that this quantity is somehow independent of n.
Maybe there is enough plane onboard capacity to deal with just 50 batteries, let's say; multiply the failure rate expected and the pax capacity of the plane and you get how many batteries you can afford to have onboard and still be able to deal with worst case scenario.
Clearly, battery packs have more legit utility for more people at much lower risk than a bomb.
It's not fallacious, it focuses the issue, and in this particular case shows that it's not about "binary thinking" it's about risk.
And my original puzzlement continues. At what level of risk, does limiting the number of devices on board to 500 or even more, actually accomplish anything?
If they're not all that dangerous, then why limit them at all? And if they're dangerous enough to limit at all, why in God's blue sky, would you allow that many of them on a plane?
We don't limit people to 1 knife per person, even though knives have utility to a lot of people who carry one with them every day.
Because it's a numbers game... the original order itself even acknowledges that the problem is not unique to power banks, but that what makes power banks unique is the amount of increased risk they pose compared to other devices, due to a higher ubiquity of them in general, and of low-quality unsafe ones.
If laptops were catching fire with the same frequency, they'd ban those too, but they're not. They technically can be made just as unsafe as power banks, but they usually aren't, and this directive is based on the frequency of occurrence of a particular type of device, not a general "what if" strategy.
Banning all electronic devices would be extremely unpopular and possibly tank their sales. They're trying to balance safety with convenience at a level that is acceptable to most people.
* Less likely to be of the same low quality
* Less likely to all go off
* Less likely that someone is doing something malicious/suspicious with it
vs. someone who has 20 power banks themselves in a bag, in which case if one of them catches fire unexpectedly, they will probably all go up at once and create a cumulative effect much more dangerous than 20 individuals.
Every one I have owned has been recalled for being a fire hazard. EVERY SINGLE ONE. I stopped buying them as a result. We're talking name brand devices, not junk off AliExpress.
If LiPo was the issue, using LiFePo4 or LTO cells for planes would be a totally reasonable alternative too. LTO cells are so safe the manufacturer of them has videos on youtube of them hammering nails into the cells, cutting them with a saw, and crushing them with a press and they don't really care.
I've seen many spicy pillows and even a thermal runaway or two on the flatpack batteries.
Although honestly how bad is it, powerbanks are very popular, I can imagine in some regions there'd be hundreds of flights taking off daily with 150+ power banks on board (the majority of passengers on a 737), and they've all landed safely.
In my city, I could scan a QR code and pay the parking meter that way. Now they've decomissioned this and you have to go to the app and select the section of the road you're parked at. Why, because scammers made scammy QR codes. Great tech, can't have them because humanity's inherent scumbaggery.
Naturally you will ask, what about tablets and laptops? They are prohibited from checked luggage for this reason. Power banks however are smaller and easier to conceal.
The risk is really in a fire developing in your bag down below in cargo, where no one can see it. By the time the fire alarms go off, it's too late and good luck if you are over water or the Arctic. If it happens upstairs they can at least tend to it with a fire extinguisher or bag/blanket.
See ValuJet Flight 592, fire in an airplane's cargo hold is probably one of the scariest ways to slowly die.
It's all about corralling risk. You can't tell people they can't bring their laptops. But power banks are unnecessary nice-to-haves.
[1] https://www.tsa.gov/travel/security-screening/whatcanibring/...
It's a bit of a grey area on jurisdiction because FAA cares about flight safety (fires) whilst TSA is primarily looking for terrorists.
United Airlines, however, prohibits laptops and tablets:
* Remove any lithium batteries from electronic devices stored in checked bags.
* If batteries cannot be removed, these devices must be stowed in cabin bags only.
* Store any spare batteries in cabin bags.
[1] https://web.archive.org/web/20260129152627/https://www.unite...
I'd rather not test this theory because of your cavalier attitude while I'm in a chair 40,000 ft over the ocean.
ICAO Technical Instructions (Part 8, Table 8-1 amendment):
“Spare batteries, including power banks: must not be recharged on board the aircraft; should not be used to charge portable electronic devices on board the aircraft; the number carried is limited to a maximum of two per person.”