> It can be explosives planted, but maybe it can be batteries modified to explode instead of burn.

That is not really a thing, from a technical point of view. Changing the chemistry of the battery (assuming that a suitably explosive one exists; these tend not to be developed very far) would just be swapping an explosive and not a modification. Doing something like adding some vessel to build up pressure within the battery sounds impractical (you’d need something very resistant to heat as a battery fire goes above 2000 K), at which point it’s not worth the trouble.

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 on the inside to at least pass superficial inspection.

This kind of damage really does not look like a battery gone wrong. It would have left all sorts of chemical residues and burned very differently.

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

CCTV footage of one of the explosions:

https://www.reuters.com/world/middle-east/dozens-hezbollah-m...

This isn't how lithium batteries fail.

Yeah, this should remove any doubt that there were explosives involved. At the 500 to 1000 mA hour capacity typically used in pagers, even tampering with the battery's venting in an attempt to build up gas pressure would at worst result in a pop and some smoke from the top of the bag.

Blowing a hole in the side of the bag and sending debris for several meters is obviously not plausible with that quantity of lithium.

The explosion in the video does show visible smoke, but there is not a visible flame or fire.

That is what explosives look like. You're thinking 80's movies explosions, made with barrels of gas.

Tom Scott explains it better than I do https://m.youtube.com/watch?v=OOWcTV2nEkU

It's about the lack of visible flame, but more about the velocity of the burn, essentially instantaneous at normal camera speeds.

Looks pretty discriminate to me, only the pager holder was affected. I've seen multiple videos with very close bystanders completely unharmed. And whoever holds a pager from Hezbollah is a member of an armed terrorist group officially at war with Israel.

Your on-the-ground, in-depth and thorough analysis of the situation is appreciated ...

All the media reports say that these were the pagers distributed by Hezbollah to its members.

Objectively this is therefore targeted, not indiscriminate...

Right but these were exploding in public right next to innocent people. There's CCTV footage of some of them exploding.

That's still a targeted attack and it seems from the media reports so far that the "collateral damage" is remarkably low, actually.

How did they make sure that only pagers carried by the armed wing of Hezbollah exploded, and not say an MP, nor one of their media workers, nor a manager in one of their hospitals? How did they know that no civilians were dangerously close when they exploded?

They didn’t. They put explosions in all the pagers which were distributed to all members of Hezbollah, military or not, and indiscriminately exploded them all at the same time, regardless of who was near the pager at the time.

This is incorrect in a disturbing way. How can something be "targeted" if the attackers simply do not and cannot know where the attacks are going to take place, physically and geographically?

Amir Tsarfati: The updated numbers:

4000 wounded of which 400 in critical conditions

Al Jazeera from a Lebanese security source:

The pagers were brought to Lebanon 5 months ago. They were boobytrapped in advance. Each device contained an explosive weighing no more than 20 grams.

whoever is good/evil aside...

hezbollah got totally owned and look like fools...relying on tech they just took at face value out of the box

To add insult to injury, they specifically used "low tech" pagers in order to avoid Israel attacks.

It looks like 1-way pagers sold in the US are powered by AA or AAA batteries: https://pagersdirect.net/collections/1-way-pagers.

That's not to say that they couldn't have put a lithium AA or AAA battery into the pagers or inserted a modified AA/AAA battery that was a combination of lithium (with greater power density) and explosive.

It's also possible that they have fancier 1-way pagers than I'm aware of.

According to this post, the pagers that exploded had rechargeable batteries. They even used USB-C, so Hezbollah must be using somewhat fancy pagers: https://x.com/BabakTaghvaee1/status/1836082246538629490

I remember reading once that Apollo is pretty much the only name in the game any more for pagers.

Surprising nobody has yet posted the make/model.

Really shows that the HN community and the victims have very little overlap.

Elsewhere here listed as: Gold Apollo Rugged Pager AR924

https://www.google.com/search?q=About+https://www.gapollo.co...

Why did the Hezbollah even leverage beepers in the first place? As in why not just use telegram or signal or some other app of choice?

Pagers don't have GPS devices embedded in them.

Apps (some more or less than others) represent a target for a nation state to pursue for information, graph analysis, bugging, etc.

Even dumb phones can be tracked by antenna triangulation, and I wouldn't be surprised if Israeli hackers are inside Lebanese phone networks...

Even a dumbphone with the GPS physically removed is going to be a lot easier to target than a one-way pager, since they are always chatting with the cell towers.

Pagers don’t have GPS devices embedded in them - that you know of.

If you can’t control your supply chain then that isn’t guaranteed.

After all, most pagers don’t contain explosive charges either.

GPS is receive only.

So that Israel couldn't track their locations via cell networks. Sure you could use Signal or w/e but it's the cell IDs and knowing where people are that was the issue. The pagers do far less, if any, two way communication so it's not likely to give away location data.

Because cellphones transmit, pagers don't.

How do you fit an explosive into a pager and still have the pager work? Like, aren't they already optimized to have everything for inside super tight?

No, a pager is optimized to be a case size that's comfortable for carrying and reading. The electronics could be the size of the smallest wristwatch, which is already dominated by its own form factor requirements, not the PCB + battery + display subcomponents that are scarcely the size of a nickel.

A typical pager is about 60 x 40 x 20mm. Much of this volume requirement is driven by the 16mm diameter 34mm long CR123 battery, a lot of it could be empty.

That battery is a relatively safe lithium primary chemistry, not a rechargeable Lithium polymer pounch or lithium ion cylinder that would risk fire and explode if the overpressure vents were omitted and the BMS corrupted, but the primary lasts for years.

I bet you could use a CR1216 battery (1.6mm thin, 30mAh, instead if 34mm long and 1500mAh) instead and have quite a good deal of spare volume in the battery for an explosive. If you filled the entire pager, that would be even more room, but much more easily detected.

According to the manufacturer the pagers have a nominal battery life of about three months so it's not likely someone would actually notice if this number is cut in half or less.

> I bet you could use a CR1216 battery (1.6mm thin, 30mAh, instead if 34mm long and 1500mAh) instead and have quite a good deal of spare volume in the battery for an explosive.

I'd be fascinated if that was the physical vector...

However, tainting a component pre-integration seems a lot more likely than simply packing explosive in the case.

Israel inserts the compromised components upstream in the supply chain, they're duly assembled into pagers, which then make their way to Hezbollah, where they're inspected, look normal, and work normally, and are then distributed.

That would still require a firmware hack to presumably trigger though (incoming message stack to component trigger).

Those thin coin cells can't output enough currents to replace most use cases. I've once tried to run ESP32 with couple CR2032, the ESP just browns out.

An ESP32 is a power hog meant to be plugged into a wall. Here are the current requirements for the various modes according to [1]:

    Active mode, 260mA to 790 mA (!)  
    Modem sleep, 20mA  
    Light sleep: 0.8 mA  
    Deep sleep: 10 uA  
    Hibernate: 2.5 uA  

Even with fancy DTIM beacons, Wifi and Bluetooth IoT devices just have a really power-hungry protocol stack and radio system to run.

Compare that to something like an STM32U5 microcontroller [2]:

    3.1 mA Run mode at 160 MHz
    19.5 μA/MHz Run mode at 3.3 V
    6.6 µA stop 2 mode with full SRAM
    1.7 μA stop 3 mode with 16 Kbyte SRAM
    0.5 uA standby mode with RTC
    0.3 uA standby mode (24 wakeup pins)
    0.1 uA shutdown mode (24 wakeup pins)

And probably more importantly, an actual low-power microcontroller can wake from sleep in something like 4 microseconds, do something for a few cycles, and go back to sleep. Pager protocols are designed for this, putting the pager to sleep for sometimes an hour, and the crystal oscillator restarts the battery-powered device moments before the frame arrives, then goes back to sleep. Conversely, booting up the whole protocol stack on the ESP32 and acquiring a connection can take literally 4 seconds.

That results in a power consumption ratio on the order of 100,000,000. ESP32s are not efficient.

[1]: https://lastminuteengineers.com/esp32-sleep-modes-power-cons...

[2]: https://www.st.com/en/microcontrollers-microprocessors/stm32...

> The electronics could be the size of the smallest wristwatch

Swatch actually used to sell a wristwatch that includes a pager! Battery life was pretty bad though; it came with a keychain accessoire to store a spare CR2032 and a battery swapping tool.

If cost per unit isn’t a consideration, I suspect you can shrink the size of the electronic components used in the pager to make room for a 20 gram explosive charge.

Pagers—especially commodity models—aren’t profitable enough to warrant cutting edge tech with the latest advances in microelectronics. Lots of room to improve things if you are making a set of them at a loss.

I think it makes more sense to think of these as explosive devices manufactured by/for Israel that are just designed to pass as pagers.

Pagers, by definition, are likely to be older technology.

The internals could be replaced with modern smaller and lower-power equivalents, requiring a smaller battery, and saving enough space.

(Or maybe somebody just donated a batch of innocent-looking devices to 'the cause', or offered a bargain on some 'extra secure' pagers?)

Thinner (less durable, but who cares?) plastic shell to free up space for explosives, but would likely be obvious if someone opened it - which might be a common thing if these were being used as remote triggering devices.

If they were using a AA battery, replace the battery with something that provides you space to work (e.g. put in a AAAA or button cell that would provide appropriate power but lower capacity) because you don't really care if the battery life drops from months to weeks.

I can easily envision a scenario that would preemptively “explain” why the pagers are internally different from past models:

Supplier: “Hey, we’ve got a refreshed model of the pager you wanted to buy in bulk. Interested?”

Buyer: “I don’t know, how do they work?”

Supplier: “Same as the other ones, minus a bit less plastic protection. With the weight savings they’ve added a new hardened receiver that’s supposedly more secure and will keep communications private. Also, they are 50% cheaper per unit…”

Buyer: “Say no more. We’ll take them.”

Because it takes a surprisingly small amount of high explosive to cause the kind of damage shown in the footage we’ve seen so far. All it would take is for the battery to be replaced with a combo package - part battery, part explosive. No need for additional internal space.

Disclosure: my first job was in the Australian Defence Science Technology Organisation, Materials Research Lab, Explosives Instrumentation Group.

One possibility is to replace part of the battery. The smaller battery can be designed to lie about its charge, or you can replace with a higher energy-density battery and use the space saved for a detonation system (perhaps even incorporating the battery itself into this) and a small quantity of high explosive, which is pretty stable and safe until detonated. Contrary to popular belief, high explosives are actually relatively safe, and usually even burn safely or are hard to ignite at all in some cases. Package it up into something that looks identical to an unmodified battery. Modify device firmware and battery control circuitry to detonate it on receipt of a specific signal and... boom.

Can you make the case out of a solid explosive material?

I had a rechargeable battery explode in my kitchen recently and it was like a small grenade went off. I'll see if I can find the photos but it shattered trim and bits went through a screen on the other side of the room.

So, an "excited" AA (which, I believe is what pagers usually use) could do a surprising amount of damage.

Photo: https://files.mastodon.social/media_attachments/files/111/40...

Those are NiMHs, aren't they? WTF? That shouldn't be possible.

Any idea what prompted the explosion?

Urg, I used exactly this brand in the past.

Is an interesting problem. Maybe the experts in the area could help here. I assume that a worn battery near the end of its life is more prone to explode, but I wonder...

Would the dead cells in the battery take part in that; or are just dead and not reactive.

In other words: if a battery has only a 30% remaining alive; or a laptop has a very worn battery, would an hypothetical explosion by overheating be much less severe? or is still so dangerous as new?.