Teenage schoolgirl 'electrocuted after rolling on to iPhone cable in her sleep' | Hacker News Reader

Teenage schoolgirl 'electrocuted after rolling on to iPhone cable in her sleep'

independent.co.uk

13 pointspmoriarty59 comments

OK, even granting the crazy notion that the charger put line voltage (which google tells me is 220V@50Hz in Vietnam) into the charger cable:

How do you electrocute yourself in bed with such a setup? That cable is going to short through the electronics easily. The tiny conductors in the connectors on both ends are going to melt and break. And even assuming you get unlucky enough to have them fail closed so you have the phone case energized... where is the ground in a bedroom situation to complete the circuit? Rolling onto a phone case at 220V is going to hurt like hell, but it won't kill you unless you can get a current across your heart.

I don't buy it.

It only takes 100 or 200 mA to kill. This is probably not enough current to melt or break any conductors, the chargers are typically designed to deliver 1,000 mA or more. Off-brand chargers are known electrocution hazards and this is not the first case of injury, not even remotely.

Remember that heating follows P = I^2 R law, so it is entirely reasonable that the conductors wouldn't melt before the attached person dies. Current across the heart is not the only way to die from electricity, but it's not really that hard to accidentally get current across the heart anyway. For example, if your arm touches the energized phone case and your leg brushes against a metal pipe in the house, that could easily complete a lethal circuit.

>It only takes 100 or 200 mA to kill

yes, but the actual amount of current that your organs are exposed to depends on the the resistance and voltage. that's why you can't electrocute yourself by putting your fingers on a 9v battery even though it's well over 200mA.

This isn't an iPhone we're talking about, this is the charger which is connected to 220V AC power. The chargers are build very small, and cheap off-brand chargers have insufficient clearance between the LV and the HV side. This is dangerous, and can cause the 220V mains to go through to the USB port. This is also a very well-known property of cheap phone chargers, and you can find many teardowns online that show what I'm talking about.

https://www.youtube.com/watch?v=wi-b9k-0KfE

https://www.youtube.com/watch?v=dfJ3Ui8IS04

http://www.epanorama.net/newepa/2016/10/25/cheap-usb-charger...

I have also seen a few videos of teardowns of actual faulty chargers. For example, there was one where some of the insulation in the transformer windings were damaged, and you would get a continuous shock just by touching the LV side of any devices that are plugged in.

> that's why you can't electrocute yourself by putting your fingers on a 9v battery even though it's well over 200mA.

If you break the skin a 9v battery can kill.

http://www.darwinawards.com/darwin/darwin1999-50.html

Exactly. If you create a 9v voltage between an artery and a vein (though 0.1v is plenty) and you generate more than around 160mA current (any battery and static electricity can do that).

Essentially you'd have to get a conductor into an artery and one into a vein, and if there is a millisecond where both are in there but not touching the skin your heart will stop. It can be restarted for a minute or so afterwards, but it won't restart on it's own.

Your skin has a "safe" (more or less) conductive layer to prevent this from occurring, with another layer with enormous insulation below that. That's why humans usually survive getting hit by lightning, yet succumb to such a stupid tiny amount of current if it gets past the skin.

> It only takes 100 or 200 mA to kill.

Only if it reaches your heart.

I don't buy it either, the charger cable would melt instantly or the usb port would explode.

I'm reminded of an article I read way back about a teenage boy who had committed suicide. Except it wasn't suicide - he died of auto-erotic asphyxiation. But no family will let that be written in the papers (at least, not immediately) so they went with the story that he hung himself and was depressed.

There was another story recently of a girl who electrocuted herself in the bath when she dropped her phone into the water while it was plugged in. I was skeptical of that as well - who wants to tell people their child committed suicide by taking a toaster in the bath? Best just say it was the cellphone.

I don't blame the parents if this is their cover up.

Why would the charger cable melt? Is this your intuitive guess here, or are you basing this on your understanding of electrical engineering?

It takes 100 to 200 mA to kill someone. A typical charger would put out 1,000 mA in normal operation. Heating follows P = I^2 R law, so it should be obvious that you can kill someone without melting your USB cable. The problem here is with putting a high voltage through the USB cable, which might damage the cable since it's not designed for such a high voltage, but even the small amount of insulation in a USB cable can be enough that the attached person will die before the cable fails.

Amperage kills you, but it takes voltage to get to your heart first. 5VDC across your body's resistance (somewhere around 1MΩ in normal conditions) is nowhere near enough current to feel, let alone harm you.

Right, and the charger is plugged into the wall which provides 220VAC. The cheap chargers are unsafe because they don't have enough clearance between the high voltage and low voltage sides of the circuit, so the isolation can fail and energize the USB port with 220VAC, for example. This is a well-known failure mode of cheap phone chargers, and it should be obvious why these shortcuts are illegal in most countries.

Teardowns of cheap USB chargers online explain what I'm talking about, for example, https://www.youtube.com/watch?v=wi-b9k-0KfE

The story about the girl in the bathtub was filled with a lot of rumors. In the end, the girl may have touched a frayed electrical cord after she dropped the phone in the tub. Electroboom has a video of him explaining this likely cause on his Youtube. I would link it but Youtube is blocked at work.

She was using a non-standard Apple charger. I have seen two of those blow up myself (as in the internal components were literally blown up, and the case was blackened). Assuming the cable was fried and the charger was in her bed, she would have been using an extension cord, which could itself electrocute her. There shouldn't be 220v output on the 5v output line, but those chargers are so crappy that anything is possible.

The only thing I don't get is why didn't the fuse blow?

The "crazy notion" is old news: http://www.righto.com/2014/05/a-look-inside-ipad-chargers-pr...

> The Independent has contacted Apple for comment but none had arrived at the time of publication.

Not sure why you would expect a comment from Apple when an off-brand chinese (I assume) charger turned out to be unsafe.

My charger that came with the Macbook Air 2011 is heavily frayed. I could see it happening with genuine cables. Not my photo but mine is very similar: https://i.snag.gy/9xXhyf.jpg

No, because Apple chargers are extremely well-designed and those cables only ever carry 12V. No-name chargers usually have sub-millimeter separation between the high- and low-voltage circuits so voltage can jump between them, electrocuting you with 110 (or 220) volts.

That's why I never ever buy no-name mains devices any more.

The difference is that those cables only carry low voltage DC. To get line voltage AC on them you'd need a short inside the power brick bridging from one side of the rectifier to the other.

Apple is very careful to isolate those two sides. Knockoff chargers, not so much. See this teardown comparing a genuine Macbook charger with a counterfeit version:

http://www.righto.com/2016/03/counterfeit-macbook-charger-te...

High voltage and low voltage should be separated by a safety gap of at least 4mm (to simplify the UL's creepage and clearance rules). On the circuit board below, the high voltage input section is at the bottom and the low voltage output section is at the top. On the right half of the board, the two sections are separated by a large gap, which is good. On the left, there should be a gap (bridged by the optoisolator). Unfortunately, traces and components pass through this area making the gap dangerously small, under 1 mm. Any moisture or loose solder could bridge this gap sending high voltage to the output.

Any particular reason that the regs just require and air gap and not a solid insulation barrier?

The other failure you need for this to happen is a line-to-output short, which is unlikely to happen in Apple's chargers, which are very well built.

Unlikely but possible. Even if the odds are very low, it's bound to happen at some points. This is the first time I hear about an electrocution from a charging cable, it happened to one girl out of millions of users. That's someone being very unlucky.

We also don't know the details of where that cable was plugged into. Some electrical wiring out there is pretty wild.

Things can be designed with large enough safety margins that "unlikely but possible" is effectively "never going to happen." If it's unlikely enough, you're up in "electrons could quantum tunnel through the insulation and electrocute someone" territory. It could happen, but I'm pretty comfortable assuming that it won't.

For an example in a similar vein, power grids send electricity around at voltages that are well outside what the wiring in your house (or anything plugged into it) is designed to handle. The primary side of a distribution transformer (the cylinders you see on utility poles) is something like 13,000-25,000 volts. I've never heard of that getting shorted into the secondary side with 25 kV being put into the residential power system.

If you look at the teardown/comparison between genuine and counterfeit power supplies (linked in other comment), I'd absolutely believe that with a large number of those adapters in use it would eventually kill someone. The high voltage side is poorly isolated and they went so far as including a fake grounding pin that isn't even connected to ground. But a well designed switching power supply is designed to not kill you.

It's scary to think that some people have these counterfeits and don't realize it's not a genuine power cord. That's the real risk here that needs to be dealt with.

Meant "Unlikely but possible" as in there was a reverse miracle going on.

Some incongruous sequence of event like a lightning hitting the wiring. The electricity coming from an illegal wiring (DIY directly from a random pole). The wiring of the house was FUBAR and following no regulations. The humidity level was low enough to allow sparks. The wire was completely frayed and fully wrapped around the child. The child was sleeping in a wet bed.

Something VERY unlikely but possible.

I'm not putting the blame on Apple but I don't understand why everyone assume that it's completely impossible that this could have been a genuine charger.

You can't electrocute yourself with the voltage in a phone charger. You have to have an isolation problem in the transformer for something like that to happen.

Not that Apple's cables are not trash for fraying so easily (a ridiculous case of form over function) but that's not the issue here.

Their pockets are deeper.

clicks, for the clicks

What will be interesting is what happens if/when this happens in the US with counterfeit parts sold by Amazon. Amazon through their comingling of inventory is playing fast and loose with the safety of its customers. They have gotten lucky so far, but eventually one of the counterfeit chargers/cables they sell is going to cause issues.

Amazon should have a UL certification required policy on anything that runs off line voltage. Even then, there's stuff on Amazon with fake UL certifications. Like this solid-state relay.[1] There's been a UL warning notice out on this item for over a year.[2] Yet it's still on Amazon. The fakes are rated for far more current than they can handle.

Switching power supplies are easy to do badly and hard to do right. I had to design one recently. A switching power supply is a short circuit waiting to happen. A switcher puts DC, as rectified line voltage, through the tiny transformer. Then it cuts the power just before the transformer saturates, becomes a small DC resistance, and starts to burn up. This happens a few hundred thousand times a second. If the switching MOSFET remains on too long, the device will burn up. A switcher is thus always on the edge of burnout.

MOSFETs tend to fail in the ON state. A static charge from a finger touch on the gate input can very easily blow out a MOSFET. The gate of a MOSFET has only a few atoms of thickness between it and the body of the semiconductor, and is very vulnerable until wired into a circuit with anti-static protection. Even in good plants, some will be damaged in assembly, especially in very dry weather.

Thus, switchers need protection circuitry. This adds considerably to the cost and complexity. Ones that don't have it will mostly work, but when they fail, you have a really bad day.

[1] https://www.amazon.com/MYSWEETY-SSR-40DA-Single-Semi-Conduct...

[2] https://www.ul.com/newsroom/publicnotices/ul-warns-of-solid-...

Nothing will happen. They will say sorry and provide you a credit and tell you not to use the device...like they do now.

I'm sure there is at least one product liabilty attorney ready to illustrate chain of commerce liability for defective products sold to consumers with a big fat wrongful death award at stake.

And even if there wasn't, the bigger deal is that someone actually getting killed would bring more media attention to both Amazon's counterfeit goods problem and the deliberate choices Amazon makes that enable that problem.

I would like this think so, but am too cynical and pessimistic when it comes to business. The avg cost of a human life is ~7.5 million [1] (old stat, may be different), that is a minor accounting issue for Amazon if they were actually sued and lost for this.

[1] https://www.theglobalist.com/the-cost-of-a-human-life-statis...

That's actually why I said the bigger issue than the liability one is the PR one.

I think Amazon is too big and too global for a couple deaths to really affect them at this point.

EEVBlog has a good tear down of the cheap chargers vs brand name chargers - https://www.youtube.com/watch?v=wi-b9k-0KfE

>Police said a "broken-down" charging brick and frayed cable were also found in the 14-year-old's bed. It is not thought those devices were made by Apple.

As much as I don’t like apples certify program for cables and chargers, this is exactly the reason we need it to exist.

No, its the reason we need brand-independent safety certification of electrical gear, of the style provided by, e.g., UL.

Its also why we need actors in the chain of commerce to have strong protection against counterfeits, which negate the protection of any safety certification program.

Apple's own cables are nothing to write home about, though I haven't heard of anyone being electrocuted.

hmmm no it sounds like we need actual regulation on chargers, not some corporation deciding on a whim.

> ... rolling onto iPhone cable ...

> Police said a "broken-down" charging brick and frayed cable were also found in the 14-year-old's bed. It is not thought those devices were made by Apple.

So, teenager gets electrocuted by frayed off-brand cable. How is this news?

The cable shouldn't be carrying mains voltage at all. It's USB; isn't that low enough current to be mostly harmless?

The cable probably was carrying mains voltage. Most of the cheap third-party chargers have very poor clearances inside, and tend to skimp on protection. It's not that rare for them to end up with a 5V DC atop a 120/240V AC mains. The phone will often still charge just fine, but the cable is dangerous.

Also, depending on the resistance as little as 10mA can be dangerous. That would mostly be wet or abraded skin, 100mA is a more general value for dangerous currents. But USB can charge at 500mA to 4A or so, depending on the version. It's only the low voltage and high resistance of skin that limits the current.

So they[0] should be calling the OEM of the brick and cable, not Apple.

[0] The people "reporting" on this incident.

The “broken down” brick could have the kind of short which would deliver mains voltage to the cable.

> So, teenager gets electrocuted by frayed off-brand cable.

That is news. But ‘electrocuted by iPhone cable’ is not what happened.

I still have my iPhone 3GS and the original cable supplied with it. This cable is pristine, pure white, no fraying of the exterior coating, completely safe to use. If you did not see the cable ends, you would think I purchased in the last year. Number of replacement cables purchased equals ZERO.

I replaced the 3GS with an iPhone 5. This phone's Lightening cable was visibly frayed within 6 months. Within a year, the interior wires' insulation cracked. I replaced the 5 cable with another cable. And another. Then stopped buying Apple cables because they are shit. I don't even want the cable provided with a new phone. Apple should offer phones without any cable and drop the price accordingly, exiting a market they clearly can't handle.

The 3GS cable and the 5 cable were used in exactly the same fashion by the same persion. The 3GS cable is still going strong after, gosh, 10 years?

I started to worry about Apple's commitment to manufacturing quality years ago because of what I saw with their cabling. This concern hasn't been allayed with the keyboard issues on their MBP line. I'd like to buy a new MBP (mine finally died after an 8 year run) but I am not going to until I see evidence that Apple irons out their quality issues. I just can't justify the cost premium when there are obvious problems.

Edit: somehow entire missing grammatically horrible!

> "Police said a "broken-down" charging brick and frayed cable were also found in the 14-year-old's bed. It is not thought those devices were made by Apple."

Moral of the story: Don't use a charger or power cable if it's visibly damaged. Physically damaged power electronics can put electricity in places it doesn't belong, creating a risk of fire or electric shock.

It's not even an iPhone cable. It's a random company cable. This is obnoxious clickbait.

Something similar happened in Ireland earlier in the year: https://www.irishtimes.com/business/technology/warning-issue...

> It is believed the fire started as a result of an electrical fault involving a mobile phone charger in the bedroom where Ms McDermott was sleeping.

A kid got electrocuted trying to charge his phone at a cybercafe in China. There was a good discussion about what circumstances would be necessary for this to happen:

https://www.reddit.com/r/watchpeopledie/comments/7aywfl/teen...

Recently my original macbook charger died with a bang and tripped 20A breakers (220v). It was in perfect condition before that. Maybe 5 years of use but rarely ever away from my desk.

First time any charger I owned did such a thing and I had many very shady chargers for various pc laptops, phones and batteries.

Replcement charger in local store, 100$. I wasn't happy.

WOW what the hell is wrong with that site it's cancer. Then i remember i am trying out the new firefox and don't have an ad blocker installed.

Scrolling videos, entire half screen ads between or in the middle of paragraphs of text.

Is this the internet norm now and ad block has just been hiding it from me?

That is bonkers. Even with turbochargers, a USB outlet of a charger should not put out more than 5V. I tested about 10 different chargers with a multimeter in the last two weeks and each one was anywhere from 4.9V to 5.1V. The isolation in the brick must have been total junk

Yikes, how would this be possible? Short in the charger that caused AC to be put on to the cable is the only thing I can think of.

Of course that happened. Not all chargers are the same. The music version: https://www.youtube.com/watch?v=ioAq7PI1Uwg

If the charger has no transformer (and no galvanic isolation) then you can get electric shock by touching output contacts (or metal parts of a phone) and any grounded piece of metal, for example a water pipe.

By the way, would not it be better to have lower AC voltage? For example, 75V or 60V don't look as dangerous as 230V.

lower voltage means more transmission losses as well as heavier/more expensive cabling to deliver the same power.

Would a GFCI be protection enough against something like this?

Probably, but it's possible for this to happen without a ground fault.

it would need to be a pretty contrived situation where the cable is frayed in two separate places, the cable is frayed in such a way that the path of least resistance is through your body (and not through the other conductor in the cable), your body is in contact with those two places at the same time, and the contact points allow the current to go through some vital organs.

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