One easy way to conceal the explosive would be to overmold it in a cavity inside the plastic enclosure. This would escape all but the most thorough inspections. And since battery terminals are typically also embedded in the plastic this can provide a clandestine supply of power and signal with something like Dallas protocol to the fuse.

> The most likely is either some explosive besides the battery, or something that looks like a battery from the outside, but is actually half explosive

That is the most plausible explanation. It can’t be an obvious thing or someone would notice it. If it looks like a plain battery pack, nobody would think of cutting it open.

The explosive here could be perhaps just 8mm x 8mm x 8mm to do the sort of blasts you see in the videos. Thats fairly small, and could easily be hidden in a device.

Inside the battery is perhaps the best hidden, but you'd need to own a bunch of battery manufacturing facilities (expensive). Cheaper would be to simply remove some other component (eg. one of two speakers) and replace it.

Most (pouch-shaped) Li-Ion batteries just look like square shapes packaged in heavy aluminum foil, with some Kapton tape to keep a small PCB with protection circuitry in place. Any determined hobbyist could buy smaller batteries and the packaging materials off AliExpress to make something that looks visually similar but has lots of space left over for explosives.

With cylindrical batteries it's a bit harder, but ultimately they are just a cylinder with pressed-on end caps. You can disassemble them (lots of videos on youtube), change the contents and reassemble them.

It is pretty high effort compared to just sticking the explosives next to the pager's electronics, but I don't think the barrier to entry is actually that high

> packaging materials off AliExpress to make something that looks visually similar but has lots of space left over for explosives.

But this, arguably, would be detectable, through low battery life?

Pagers last for a very long time. Some one-ways can last for over a month. At that point, you probably wouldn't notice it's just over 3 weeks, or maybe think the product is lying in the advertisements and lasts less but not enough to replace the "company provided" one.

> Some one-ways can last for over a month.

More like a year or two off of a single AAA battery.

There are tons of more likely explanations for that, though, with the top of the list being "dang bosses bought low quality pagers".

And if they can make the combined package big enough that the battery life is still acceptable, it's even less likely that someone will pull the pager, notice that they should be getting "great" battery life instead of "just ok", and investigate deeply.

I read elsewhere that Hezbollah recently changed to this pagers to communicate, maybe it those who put the bombs bet on the fact their victims wouldn't have time to realize that the battery have shorter life than advertised

Not impossible they modified the firmware to improve battery life - look how sophisticated Stuxnet was.

I recently discover explosive welding is a thing. It uses PETN packaged as a thin sheet.

https://en.wikipedia.org/wiki/Detasheet

> Inside the battery is perhaps the best hidden, but you'd need to own a bunch of battery manufacturing facilities (expensive).

Do you?

What stops you from just taking a smaller battery and packing it with some plastic explosive into the typical "battery foil"? I'm sure the IDF is capable of doing that at scale.

Something along these lines is my guess. Focus on the batteries. You can replace individual cells with explosives and cause the remaining cells to overheat to start the explosion.

Most battery packs have integrated power management chips, so you could focus on modifying the battery firmware.

You could have another component send a message to the power management controller to trigger it.

You could also use the power controller's internal current sensor and clock to watch for a device event (power draw from the screen at a certain time or the power profile for a specific set of CPU instructions), giving you means to trigger it without modifying any other part of the device.

> You can replace individual cells with explosives and cause the remaining cells to overheat to start the explosion.

That won't work. You can use C4 and other modern plastic explosives as cooking fuel; they burn nicely. Getting them to explode requires a detonator.

A quick google search reveals multiple battery manufacturing facilities in Israel, including domestic and foreign owned corporations. A special order of batteries seems very plausible.

I don't see someone like Iran or Lebanon being able to do that, but Israel has a great technical know-how and a ton of resources. Making custom batteries, with embedded explosives seems plausible.

Israel doesn't have "ton of resources". They are smart enough to work with limited resources they have to effectively achieve their goals.

It's military budget is on the order of $20B which is quite decent for that size of a country. It's enough to build some realistic looking batteries and/or pagers combined with the technical base they have.

$20B is by far less than Google or Microsoft make a year in revenue. It's nothing compared to the amount of enemies surrounding Israel, a country that is literally desert with no natural resources.

Still more than enough to custom-build a bunch of batteries. I have no love for the Israeli regime, but this is ridiculous.

What did the "Israeli regime" do to you? Has your pager exploded too?

On a serious note, Israelies are our allies. You don't have to love them, but they are standing on the forefront of fighting against the enemies of the West. If not them, you would be on their place.

Considering the tech industry of Israel and the bottomless military/security budget, this is very plausible.

Also considering that a plan like that must have taken many months/years start-to-end, this just makes me wonder what else is booby-trapped(?), fridges? laptops? microwave ovens? the next door flat? flower pots?

Stuff like that take the paranoia levels all the way to 11.

a lot of people claim "we will strike fear in the hearts of our enemies".

Israel makes them quietly shit their pants instead.

They did certainly not make them shit their pants, what a childish idea.

They'll cause a big backlash. And the best they have are again suicide bombers in Israeli cities

eh, they were launching rockets into Israel daily, and now they walk with a limp and will freeze every time something beeps. I count that as a win.

no, there won't be suicide bombers in Israel again. they've gotten much better at finding the rats - see original article.

I fail really to see the difference between Hezbollah lunching rockets into Israel and Israel's pager bombs. Except the latter are pretty well targeted.

Frankly I believe that the people complaining pagers wouldn't if Hezbollah had managed to do the same to Israel. They'd celebrate it. So really they're just unhappy that the team they're emotionally invested in is getting shellacked.

There is nothing unique or special about Israel in that respect…

I love that your comment says this kind of striking terror in the enemy is completely unremarkable while the other says no such thing happened!

It’s not unremarkable, or even very common. But lots of countries do this besides Israel (targeted strikes to eliminate targets and remind would-be targets that it’s hard to get out of reach). It’s true that they tend to be on the high-tech side compared to say Iran, and that democracies most of the time at least try to make it look legal.

I disagree with the other post you mention, FWIW.

The pagers in question is believed to be a dry cell operated model. It could be a rigged AA battery.

...oh no. They must have handed out those USB rechargeable batteries as an upgrade. The bad guys want to be able to charge it, so they would be incentivized to align the charge port with case back and explosives facing the user. Then the battery could be triggered by time since synchronization && backlight current draw && button press beep.

You are probably right but explosives risk detection, either by the militants or by the airport security if taken to a flight to a country with serious security.

Detection by airport security might probably be avoided using the right type of explosive. I have no real idea about this, but I suspect that any nation-state with enough budget and know-how can manufacture undetectable or very hard-to-detect explosive devices. If the explosive is encapsulated in a sealed airtight container, which is properly "washed" after manufacturing, I guess there's no way to chemically detect the explosive inside. Not sure about how to avoid X-Ray detection but that's generally not the way explosives are actually detected.

And, is the device anyway going to pass through airport security? I guess the owners are not really travelling on commercial airliners.

These devices apparently were distributed to thousands of operatives. I would imagine that people having those are some of the more elite ones and they probably will travel for business reasons, be it personal business or Hezbollah business. A few who choose to take their pagers with them(i.e. will not be heading straight home after travel, so brings the pager) are huge risk IMHO. Even a single incident may reveal the plot.

I don't know how those detectors at the airports work exactly but they are probably playing cat and mouse game with the people who are into smuggling things and as a result they are probably aware of the more advanced methods like injecting things into the plastic.

This is the reason why I think the explosives were most likely hidden in the batteries. Some explosives have similar enough chemistry that they cannot be told apart from legitimate battery packs by the scanners.

This is a known threat, and this is the reason why some airports do extra checks on some travellers (for example asking them to turn their laptops on, asking them when and where they got the laptop and etc.)

https://en.m.wikipedia.org/wiki/2017_electronics_ban

The scanners only test for the signatures of common chemical structures of explosives, like nitro and nitrate groups, which make up the bulk of mass produced explosives. There are many lesser known chemistries for high explosives that will not be detected by these scanners. Probably the best known example actually used by terrorists are explosives based on peroxide chemistry but there are several others.

A friend of mine who visited Lebanon (and the Hezbollah museum, he gave me a Hezbollah cap by the way) then went to Israel and was subjected to a thorough explosive material search. They basically swiped some kind of broom all over his body (with a focus on genitals) and put it in some device (some kind of spectrometer ?).

This sounds like your regular check for explosives at any other airport in Europe or the US, probably many other places.

news reports suggest 1000+ of these devices exploded.

In a country where lots of people would happily crack open the lid of a device to replace the battery or otherwise tinker, the explosives must have been well hidden, not just tucked into the case.

it is my understanding that the devices had been delivered recently

I work in the battery space.

All you have to do is build replacement batteries without the pressure relief vents. You can easily get a Chinese manufacture to do this for a fee and properly some complaining about how stupid it is to do.

Then wrap it in some nichrome wire and have a micro run some power through it. The nichrome wire will overheat the cell really quickly causing the cell to rapidly over pressurize and boom.

Small pouch or prismatic cells that would be used at the size of a pager generally won't burn. And I speak from experience of doing stupid shit to them in the name of testing, nothing like using the nail puller side of a hammer to puncture them, or rigging up a fixture with 3 concrete nail guns to shoot it or well, fun stuff

This wasn't a battery, it doesn't match the damage seen. The evidence has all the hallmarks of a small charge of high-explosive.

These pagers probably had puch cells - those catch fire violently, but don't explode because the film can't contain much pressure.

Explosions are essentially about extremely rapid expansion of gasses. I don’t see how a battery, even one that is rigged to fail, can explode in an instant. Shorting out, overheating, and ultimately exploding because the battery compartment can no longer contain the expansion has got to be too slow by many orders of magnitude. Your theory makes no sense to me.

Pressure vessels without a pressure-relief system explode once sufficiently pressurized.

Sure, but can you get 1,000 of them to explode simultaneously that way? You'd think there'd be some variation in the time of explosion, at least by tens of minutes or hours, maybe even by days.

Shorting the battery would probably cause an explosion in around one minute. That's close enough to simultaneous.

From https://www.mdpi.com/2313-0105/8/11/201

A puncture causes runaway/explosion in seconds. Overcharging takes 13 minutes. There's not good data on a dead short (because it's unlikely during normal operation), but it's going to be between those on the faster end. From personal experience a shorts cause things to get noticeably hot after about 10 seconds, the graphs show that once you hit 60C things rapidly get worse.

A relay may have been required to hold the short as the battery stops supplying voltage.

The Reuters article said they exploded over an hour

Batteries aren't pressure vessels though. Pressure vessels are generally decently large; how are you going to get one with significant capacity inside something as small and lightweight as a pager? Just putting in some plain explosives makes a lot more sense.

A battery without pressure relief is definitionally a pressure vessel. How much damage it actually does when it explodes is another question entirely.

It's a very minimal amount of pressure it can withstand, is the point. Certainly nowhere close to lethal explosive pressure. It's not a pressure vessel in the sense of the kind of pressure vessel it takes to make an effective bomb.

A battery pouch is a terrible pressure vessel under these conditions. It’s designed to bulge and deform to avoid catastrophic failure. It would need to be replaced with some very stiff material that can withstand the first step of thermal runaway. A battery not submitted to mechanical stress (e.g. by being punctured, hit very hard or shot at) is going to get quite hot before expanding.

It’s the simultaneous timing thats a giveaway for me. Maybe you could have a few batteries explode but 2000 of them? It’s too clean to be just batteries imo.

Possibly hydrogen explosion.

Ok well someone's on some TLA's list now.

How do you ensure they all blow up at once?

Modified firmware that triggers on a receipt of a particular message and/or from a particular number?

> Then wrap it in some nichrome wire and have a micro run some power through it.

Presumably some software that triggers this?

I see some reports claiming that the trigger message was “07734 58008” but hard to tell if all these accounts are serious.

My guess would be that not only the battery but also the main board was modified to initiate the action.

edit: why do you think I'm not sure if they are serious? Calculator jokes are not a niche humor :)

> I see some reports claiming that the trigger message was “07734 58008” but hard to tell if all these accounts are serious.

Clearly someone's not being serious.

Good catch. Your 3rd grade, calculator-using self is serving you well.

It's extremely hard to tell if these accounts are, in fact, serious

07734 58008 means "Boobs, hello". That does not seems serious.

The accounts may be serious (even accurate!) but whoever chose the numbers was not being serious in their choice of number. Or it's quite the coincidence.

I want to see a video of this compared to explosives.

Very interesting, so the battery modification is plausible it seems.

I agree with this theory even though I am not even sure it would require a specific modification like the mentioned heating wire, if you can simply use the existing circuit with some instruction to cause component overheating with the same effect.

Another reason I do not believe it was an explosive is that a clandestine explosive installation would have resulted in far greater damage and included shrapnel. Because why would you not install very high explosives and shrapnel in a shape charge that directed the explosion into the likely body of the wearer if you are taking the risk of intercepting and making a physical modification.

This is also less Stuxnet and more infiltrating insecure systems of vehicles to drive by wire accelerate cars into objects. There have been examples of this

> a clandestine explosive installation would have resulted in far greater damage and included shrapnel

No and not much. The amount of explosion you get is proportional to the amount of explosives used. Small amount of explosives == small explosion.

Shrapnel is specifically engineered into explosive military weapons - it is not an innate property of explosive reactions. If you want a lot of shrapnel you have to design the case to fragment (e.g. grenades) or pack the area around the explosive with the stuff you want to become shrapnel (as with many bombers packing nails and screws and bolts etc., around their bombs). A small explosion in a mostly plastic device will result in a small amount of small pieces of plastic being scattered, which might harm bystanders but is by no means guaranteed or even intended to do so.

It would seem if they're going to all this trouble in the first place to design a substitute case of materials that had good shrapnel effects.

A shape charge would be pointless because you can't guarantee how the device is worn- one news article mentioned most people carry them in their pockets, so a shape charge would be blowing most of the energy away from the target in 50% of the cases.

With a pager you can be pretty sure the target will be holding it with one hand and looking at the screen. Reports indicate the pagers beeped shortly before they went boom. So if the blast is focused in the plane normal to the screen that would focus it into the hand and face of the target. No idea whether that's actually a good idea or not.

A shaped charge need not be unidirectional. It could be focuses along an axis, resulting in a two-way explosion that would be more damaging than a symmetrical one. Two copper disks on either side of the charge would constitute a functional two-way shaped charged.

I think the grocery store security video supports the two directions idea. If you watch carefully it looks like a pressure wave away from the target and clearly something takes the target down. Perhaps a pressure wave in the opposite direction too.

Doing much more damage 50% of the time might be more effective, if an undirected explosion is too weak to kill anyone but a directed (and lucky) one could.

I've seen some videos. Shattered hips, abdominal wounds, hands without fingers. I haven't seen any dead person, just maimed bodies. Mission successful I guess. Oh and one kid.

Why was this dinged?

Is the information wrong?

I don’t think they’re saying you’d need to change the chemistry though, they’re saying they could have altered way it was packaged so that when it started burning there was nowhere for the gas to go.

Similar to how firecrackers work. If you take a firecracker apart and light the powder, you’ll get a flash and a lot of smoke, but no bang. The explosion comes from the pressure building up in an enclosure.

Disclaimer: not a chemist. Just a former unwisely curious kid

"If you take a firecracker apart and light the powder, you’ll get a flash and a lot of smoke, but no bang. The explosion comes from the pressure building up in an enclosure."

True. But if you open enough firecrackers and put the powder in a small plastic container you will not get a bang but a buff and a fireball the size of a car.

Disclaimer: I am a chemist and a former very unwisely curious kid