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Comment by Reason077 | Hacker News Reader

> “you've been disallowed from putting lithium batteries in checked luggage for at least 16 years.”

This rule only applies to loose (spare) Li-ion batteries, not batteries which are installed in a device.

Batteries over 160 Wh (in some cases, 100 Wh) are banned whether they’re in a device or not, but that’s far bigger than any phone battery: an iPhone 16 Pro Max battery is about 16 Wh, and typical laptop batteries are around 60 Wh.

IATA Li-ion battery fact sheet: https://www.iata.org/en/iata-repository/pressroom/fact-sheet...

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This rule only applies to loose (spare) Li-ion batteries, not batteries which are installed in a device.

I've heard of people ordering 18650s online and getting them along with a free flashlight in which they came; I wonder if this regulation is why.

Almost definitely for import tax/restriction reasons. Putting the battery inside a cheap flashlight places it in a separate category than a battery by itself. Felt on the bottom of Converse sneakers to classify as slippers is a classic example of this.

The battery limit described is for individual passengers, not air freight.

Air freight for Li-ion batteries is pretty strictly regulated too, especially when the freight is carried on passenger aircraft.

See UPS Flight 6 for a very good reason about why the flight of lithium batteries is regulated

As always, Admiral Cloudberg has a deep-dive into this crash: https://admiralcloudberg.medium.com/alone-in-the-inferno-the...

Slightly off topic, but she does an amazing job.

I watched both Mentour Pilot and Green Dot Aviation's videos about it. Mentour Pilot's video terrified me, as it simulated the audio of being inside the cockpit, with GPWS, fire warnings, the sound of the fire all going on at the same time

Green Dot Aviation: https://www.youtube.com/watch?v=T7uw6VzWHcM

Mentour Pilot: https://www.youtube.com/watch?v=Y50saxfTqQA

Yup, any time I order anything from Amazon that has lithium it comes with a big warning sticker about shipping restrictions. Even if it's a fixed battery inside a device.

Indeed. If it’s sold as already in a device, it doesn’t need the battery sticker and in general the regulations around shipping it are significantly less onerous.

Interesting, at the airport I always see general "no (devices with) batteries in checked luggage" signs.

One time I had an old phone with battery removed in checked luggage and when I arrived at my destination, I saw they fiddled with the tsa lock and the phone was taken out of the envelope I had it in and just lying on top of my clothes. I mean maybe they saw it in an xray and wanted to steal it and then saw it was some old junk phone, no idea how good the xrays come out to tell beforehand whether you're dealing with an iPhone or 7 year old android midrange...

Notably the 16” MacBook Pro (every model since 2019) goes right up to the 100 Wh limit.

For comparison, 100 Wh is 360,000 joules, which is just under either the energy released by explosion of 100 grams of TNT, or the kinetic energy of a small car at highway speeds, or the kinetic energy of 1 gram meteor hitting Earth.[1] (Sorry, I've never been a fan of the "Wh" unit and so wanted to put that total energy into layman terms.)

[1] https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy)

Or a McDonalds medium fries?

EDIT: doh, just realised you were comparing with other forms of damage. That said, I think its truly amazing that a snack has the same energy as a nasty car crash. Mind blown.

That is, 100 Wh = 86 kcal.

Enough energy to heat 1 kg of water by 86°C (or 86 kg of water by 1°C).

To me it is hard to visualize how much damage the total energy gained from digesting chemical bonds of food could do to an airplane. I can better visualize the damage that could be done by a highway car crash or detonating a handful of TNT in an airplane.

These counterfactual comparisons are a slippery slope and not as helpful as you think. I hardly think that you, I, or most others have an intuitive understanding for what happens when a 1 gram meteor hits earth. Have you ever witnessed that?

The average failure state of a battery is not similar to detonating a handful of TNT on an airplane, which is a more instantaneous explosion. Sure, some battery failure states are violent and would unquestionably be a cause for an airplane to call a mayday and land, but something like puncturing a soft-cell battery is still a slower release than TNT.

We should just expect people to get better at understanding useful units — I'd prefer someone learns Wh since it is indeed a useful metric—kWh is the usual major unit of energy at home, and Wh is just smaller than that.

I was trying to guesstimate a theoretical upper-bound on the damage. Looking at youtubes online, it seems a labtop battery explosion is still scary and more like a handful of firecrackers than TNT, but what actually seems worse is that the explosion is followed by the labtop being on fire and producing subsequent smaller explosions. So the worse case is that the fire ignites other stuff in the plane, which includes other lithium batteries.

Can the battery actually release that energy as explosively as the TNT can? I mean under normal corcumstances, not maliciously modified.

many laptops are reaching 100wh limit, dell xps 16 has 99.9wh iirc

And people dont travel with single device anymore. My usually setup has 72wh powerbank, ~20wh phone and 90wh laptop, and various smaller gadget. They are reaching nearly 200wh

(100Wh / 3.7V ~= 27000 mAh, 160Wh / 3.7V ~= 43000 mAh. Wh represents theoretical total energy, used as a normalized comparison, and Ah is used to practically determine max safe charge/discharge rates)

I also thought the reason you couldn't travel with unattached spare batteries was because something could bridge the + and - and create fire from a short, not because they were lithium. Like, traveling with my little power bank wasn't an issue because it's all enclosed.

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