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Comment by xn | Hacker News Reader

Is 34, about 6 per year, a lot? How many people do fractal wood burning? How many people are electrocuted using jumper cables on cars each year?

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12V car battery electrocutions? Uhm, I would guess approximately none?

It is not the voltage that kills you. It is the current and a car battery can deliver quite the current.

At such a low voltage, and a DC voltage nonetheless (so you're only dealing with resistance, and not impedance), you will never get enough current through you, even if you'd just waded out of the ocean.

Not through the resistance of a person. For electrocution, the voltage is the indicator of hazard. The current required is very small.

V = IR. It's voltage that causes the current to flow.

You can certainly get a lethal shock from a car battery if you pierce the skin with an electrode attached to one of the terminals, due to the reduced resistance through the body, but you're not going to get one through your skin.

The amount of current required to stop you breathing is as low as a few hundred mA, and only 1A to stop your heart in v-fib.

On the other hand, even wet or broken skin should offer about 1 kilohm; so your chances of being electrocuted by a car battery are slight.

> and only 1A to stop your heart in v-fib

Much less than that, depending on length of exposure. The AC death graph (probably not applicable to this DC scenario, but illustrative nonetheless):

https://upload.wikimedia.org/wikipedia/commons/7/7f/IEC_TS_6...

Red is fibrillation with increasing probability of occurrence. Yellow is injury, green is harmless, and blue is imperceptible.

I believe that AC is way more dangerous than DC, and particulary the low frequency (50-60 Hz) that are used on normal mains, once upon a time lighting in tunnels (during excavation) was through a frequency converter that elevated frequency (i.e. essentially making AC more similar to DC):

https://news.ycombinator.com/item?id=20736124

According to:

https://www.allaboutcircuits.com/textbook/direct-current/chp...

A DC shock may stop the heart (which once the contact is broken is easier to restart) whilst AC males it fibrillate, and there is the "tetanic" reaction induced by AC that in many case might make the contact last longer or be impossible to break.

The old, basic rule is - in case of doubt if a wire is live - to touch it first with the back of a finger, and never with a fingertip, as the reaction to the shock would be to close the finger/hand around the wire in a very tight grip.

> I believe that AC is way more dangerous than DC

Yes. I pointed this out myself several months ago:

https://news.ycombinator.com/item?id=28682725

It is usually voltage that kills you, but not all electric shocks are equal. The type that kills you quickly is one that goes through the heart, disrupting its rhythm. This happens, for example, if you use both hands to work on something electrical. It doesn't need much current at all. Electricians are trained to not use both hands. If you use only one hand the shock is more likely to be straight to ground. In that case a high current is going to do more damage to you, but might not actually kill you. But in any case you need enough voltage to overcome the resistance of the skin the first place.

It's an interesting point. Car jumper cables maybe isn't a good example, but what about extreme sports or even just car crashes etc? Is there something in particular that makes this activity worthy of so much attention? Is it perhaps that electrocution seems very dramatic, or maybe the fact that many people have one of these deadly devices in their own kitchens?

The questions were meant to be rhetorical questions, but did get plenty of informative answers that using jumper cables with a 12V car battery is unlikely to result in accidental death.

Any article/video that says N number of people died doing X should provide some context about how many people do X, how many people die doing Y, which is similar to X.

There are plenty of ways that it could result in accidental deaths, just not by electrocution. For example, if you have an open container of gasoline (also known as a fuel-air bomb) and you accidentally strike both jumper cables together (spark).

> How many people are electrocuted using jumper cables on cars each year?

Unless you have a pace maker or something getting electrocuted by a car battery is going to be hard. A car batter outputs 12 Volt. The transformer in a Microwave oven outputs 2000 volt. 2000 volts is instant death even with super low current.

Huh? The first thing my dad did after showing me how to jump a car was to warn me never to touch the live ends together because they would “do this!” and proceeded to do it and show me the … hang on, I’m going to go make a video for clicks.

>How many people are electrocuted using jumper cables on cars each year?

That's easy question. None. The 12V from a car battery is much less hazardous than the 20000V from a microwave transformer.

> How many people are electrocuted using jumper cables on cars each year?

Approximately zero over the last hundred or so years, I'd venture.

fwiw, that's just 34 in the US. Apparently the numbers in other countries are also quite high, so we're probably looking at hundreds worldwide. Considering YouTube is making money off it, I think even 34 is an unacceptably high number.

How would car jumper cables electrocute you? Aren't car batteries 12v?

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