5 ms·

I can kill you with a 12V car battery at 8 amps clamped to your fingers, no problem.

wlesieutre 9y ago
No you can't. It has the capacity to deliver 8 amps, but your body's resistance is too high to draw that current. https://www.seattlepi.com/news/article/Car-Talk-Car-battery-can-shock-you-but-it-1203143.php https://www.seattlepi.com/news/article/Car-Talk-Car-battery-... EDIT - here's some math: The U.S. Navy FIRE CONTROLMAN Volumes 01 - 06 & FIREMAN gives 1500 ohms as a common resistance approximation between extremities, either hand to hand or hand to foot, for an average human body. I = V/R = 12V / 1500 Ohms = 0.008 A 8 mA is not nearly enough to kill you.
- FreeFull 9y ago
  On the other hand, if skin is breached, the resistance is quite a bit smaller, and it won't take too much voltage to cause a deadly current.
  - wlesieutre 9y ago
    There's a story floating around the internet of someone having done by stabbing through their thumbs with a 9V multimeter, and maybe it's possible, but I'm skeptical of the story's veracity. I can see those wacky stories for a lot of situations, but you'd think with somebody dying that there'd be some kind of incident report or other documentation. But sure, it's probably best to not touch the car battery terminals when your hands are bleeding.
  - lightedman 9y ago
    Ding, this person isn't thinking about how sharp those cable clamps are and how strong of a spring it has which can drive that clamp well past the skin. This is how we killed animals on the ranch I grew up on. I know very well what will kill you electrically-speaking.
- lightedman 9y ago
  You don't know how sharp battery clamps are, do you? They will easily penetrate the skin with those heavy springs and sharp points. At that point, your skin resistance means jack.
olyjohn 9y ago
I'm genuinely curious how you'd do that... I can touch both battery terminals with my hands and feel nothing. Even if my hands are damp, nothing happens. My battery is capable of outputting over 700amps.
- mikeash 9y ago
  People have latched on to the mantra that it’s not the volts that kill you, it’s the amps, but they never seem to remember that you need a certain voltage to get those amps in the first place.
  - planteen 9y ago
    Exactly. And also the mantra "electricity takes the path of least resistance". While that is true, some people seem to interpret it as "electricity only takes the path of least resistance" which is very wrong. Electricity takes all paths!
    - setr 9y ago
      I don't know squat about electricity If electricity takes all paths, then whats the point of the mantra? It includes the highest and least resistance, and everything in between. The mantra is almost deliberately meant to mislead?
      - planteen 9y ago
        > If electricity takes all paths, then whats the point of the mantra? It includes the highest and least resistance, and everything in between. The mantra is almost deliberately meant to mislead? Maybe mantra wasn't the right word, Wikipedia calls it a heuristic. Regardless, I agree it is very misleading and I would never say anything like that when teaching or explaining electricity. Why does it keep getting repeated? Who knows. Inertia of the masses without a much understanding of electricity would be my guess... https://en.wikipedia.org/wiki/Path_of_least_resistance https://en.wikipedia.org/wiki/Path_of_least_resistance
      - 9y ago
planteen 9y ago
No way. If that were the case, people would be dying all the time when trying to jump cars. You would need to wear lineman gloves to do it safely and working on cars in general would be quite hazardous. I've touched both car battery terminals before. You don't feel a thing.

No you can't. It has the capacity to deliver 8 amps, but your body's resistance is too high to draw that current. https://www.seattlepi.com/news/article/Car-Talk-Car-battery-can-shock-you-but-it-1203143.php https://www.seattlepi.com/news/article/Car-Talk-Car-battery-... EDIT - here's some math: The U.S. Navy FIRE CONTROLMAN Volumes 01 - 06 & FIREMAN gives 1500 ohms as a common resistance approximation between extremities, either hand to hand or hand to foot, for an average human body. I = V/R = 12V / 1500 Ohms = 0.008 A 8 mA is not nearly enough to kill you.

FreeFull 9y ago
On the other hand, if skin is breached, the resistance is quite a bit smaller, and it won't take too much voltage to cause a deadly current.
- wlesieutre 9y ago
  There's a story floating around the internet of someone having done by stabbing through their thumbs with a 9V multimeter, and maybe it's possible, but I'm skeptical of the story's veracity. I can see those wacky stories for a lot of situations, but you'd think with somebody dying that there'd be some kind of incident report or other documentation. But sure, it's probably best to not touch the car battery terminals when your hands are bleeding.
- lightedman 9y ago
  Ding, this person isn't thinking about how sharp those cable clamps are and how strong of a spring it has which can drive that clamp well past the skin. This is how we killed animals on the ranch I grew up on. I know very well what will kill you electrically-speaking.
lightedman 9y ago
You don't know how sharp battery clamps are, do you? They will easily penetrate the skin with those heavy springs and sharp points. At that point, your skin resistance means jack.

olyjohn 9y ago

I'm genuinely curious how you'd do that... I can touch both battery terminals with my hands and feel nothing. Even if my hands are damp, nothing happens. My battery is capable of outputting over 700amps.

mikeash 9y ago
People have latched on to the mantra that it’s not the volts that kill you, it’s the amps, but they never seem to remember that you need a certain voltage to get those amps in the first place.
- planteen 9y ago
  Exactly. And also the mantra "electricity takes the path of least resistance". While that is true, some people seem to interpret it as "electricity only takes the path of least resistance" which is very wrong. Electricity takes all paths!
  - setr 9y ago
    I don't know squat about electricity If electricity takes all paths, then whats the point of the mantra? It includes the highest and least resistance, and everything in between. The mantra is almost deliberately meant to mislead?
    - planteen 9y ago
      > If electricity takes all paths, then whats the point of the mantra? It includes the highest and least resistance, and everything in between. The mantra is almost deliberately meant to mislead? Maybe mantra wasn't the right word, Wikipedia calls it a heuristic. Regardless, I agree it is very misleading and I would never say anything like that when teaching or explaining electricity. Why does it keep getting repeated? Who knows. Inertia of the masses without a much understanding of electricity would be my guess... https://en.wikipedia.org/wiki/Path_of_least_resistance https://en.wikipedia.org/wiki/Path_of_least_resistance
    - 9y ago

planteen 9y ago

No way. If that were the case, people would be dying all the time when trying to jump cars. You would need to wear lineman gloves to do it safely and working on cars in general would be quite hazardous. I've touched both car battery terminals before. You don't feel a thing.