# Why don't I get shocked by batteries? **URL:** \ **Category:** Factual Questions\ **Created:** [February 7, 2003, 8:02pm UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545 "2003-02-07T20:02:31Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [February 8, 2003, 3:35am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/21 "2003-02-08T03:35:15Z")
> [@](#): > > \*Originally posted by Rick \* > **12.5V/0.125ohms =10A Not exactly a meat cooker.** It’s still 125 Watts. Try sticking a 100 Watt light bulb in your mouth for a while. ---
**Author:** ![Cillasi](https://avatars.discourse-cdn.com/v4/letter/c/71e660/32.png) [@Cillasi](https://boards.straightdope.com/u/Cillasi)\ **Post date:** [February 8, 2003, 3:36am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/22 "2003-02-08T03:36:06Z")
> [@](#): > > \*Originally posted by Max Carnage \* > \*\*I do however want to meet the woman who is able to do this. Maybe invite her up for…coffee. \*\* The WOMAN??? I want the MAN who can do this…please! ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 8, 2003, 4:14am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/23 "2003-02-08T04:14:11Z")
> [@](#): > > \*Originally posted by Desmostylus \* > \*\*It’s still 125 Watts. Try sticking a 100 Watt light bulb in your mouth for a while. \*\* Well having an above room temp IQ I would take the light bulb out of my mouth very quickly. And using \*\* danvanf’s \*\* numbers 12V/60 ohms = 0.2A 0.2A\*12V= 2.4W I will take his word for the tingle (in all the years I have worked on cars, and all the things I have done with them I have never licked a battery. I don’t intend to start now) ---
**Author:** ![SlickRoenick](https://avatars.discourse-cdn.com/v4/letter/s/e68b1a/32.png) [@SlickRoenick](https://boards.straightdope.com/u/SlickRoenick)\ **Post date:** [February 8, 2003, 4:48am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/24 "2003-02-08T04:48:00Z")
I have a fluorescent lantern that uses 8 Ds. How come if I turn the knob to on, unscrew the cap and put my DRY hand across the contact points i get the bejesus buzzed out of me? ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [February 8, 2003, 4:51am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/25 "2003-02-08T04:51:02Z")
> [@](#): > > \*Originally posted by Crafter\_Man \* > \*\*Wrong. > Current capability doesn’t matter. > Try again. \*\* You are so wrong. Have you tried it? Have you held onto the -ve terminal of a car battery with wet hands and licked the +ve terminal? Man, I get wicked sparks and acrid smoke when I connect up my car batteries with jumper cables. I’ve licked a lot of things, but I’m doing THAT. ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [February 8, 2003, 4:53am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/26 "2003-02-08T04:53:20Z")
In my dreams. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [February 8, 2003, 4:58am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/27 "2003-02-08T04:58:24Z")
> [@](#): > > \*Originally posted by Muldoon III \* > \*\*I have a fluorescent lantern that uses 8 Ds. How come if I turn the knob to on, unscrew the cap and put my DRY hand across the contact points i get the bejesus buzzed out of me? \*\* That’s different. A fluorescent tube operates at a much higher voltage. The lantern contains an inverter which boosts the voltage to dangerous levels. ---
**Author:** ![danvanf](https://avatars.discourse-cdn.com/v4/letter/d/13edae/32.png) [@danvanf](https://boards.straightdope.com/u/danvanf)\ **Post date:** [February 8, 2003, 5:02am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/28 "2003-02-08T05:02:08Z")
FranticMad, Crafter Man is on it. Ohm’s Law simply doesn’t allow it. The potential for current flow doesn’t mean anything. If it did every electrical device we have would smoke, in fact switches wouldn’t even turn off. A switch isn’t really a switch, it’s just a very large resistor. Note: Ohm’s law isn’t a theory. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [February 8, 2003, 5:18am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/29 "2003-02-08T05:18:41Z")
While I am certainly not advocating licking anything under your auto hood, 12 volts is not going to fry your tongue. It will certainly be uncomfortable enough to convince you to take whatever 12 volt source you have out of your mouth right away. Eight AA batteries will do the same thing. (OK, to be absolutely accurate, the double A’s won’t do it for as long, but I don’t think that’s really a problem.) Those sparks come from metal to metal connections being made and broken at very short distances. They look impressive as hell, but they don’t cause injury from electric shock. They can burn you a bit if you are holding on to the business end of a pair of jumper cable clamps. (Why you would be doing that is a different question, and not all that hard to understand, given the assumption that you need to know why licking your car battery is a bad idea.) Just a side note: Don’t make the final connection at the battery post when using jumper cables. Make the final connection to the car chassis of one of the two cars, at some point away from the battery, or any fuel system elements. Those sparks can ignite fumes, hydrogen, or gasoline. Be safe. ## Tris “In my opinion, there’s nothing in this world, Beats a '52 Vincent, and a red headed girl.” ~ Richard Thompson ~ ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 8, 2003, 5:34am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/30 "2003-02-08T05:34:57Z")
Basic electrical class is now in session **FranticMad,** there are a few things you need to learn about how this electrical stuff works. **CRafter\_Man** is right, current capability doesn’t matter. Let’s say that my car’s starter motor draws 120A, and I change out the battery for one that has twice the amperage capaicity. What will happen? Will my engine crank twice as fast? No. The reason is ohms law. It takes one volt to push one amp of current through 1 ohm of resistance. V=A_R (For the engineers in the group I’m not using E and I cause I don’t feel like doing the expalantion) So in my starter circuit 12V/0.1ohms = 120Amp draw to the starter. It does not matter if the battery is capable of 200A or 500A as long as the resistance doesn’t change the current flow won’t go up._ Votlage and resistance determine current flow. No, I have never licked a auto battery terminal. Automotive batteries have lead posts (not good for you) and the electrolyte is sulferic acid (really bad for you) the reason you get sparks when you connect jumper cables is that you are connecting a low resistance circuit and a lot of current is flowing. The ultimate example of this would be to drop a wrench across the two battery terminals. Resistance would go to zero and current flow would go to infinity (or as close as your battery would deliver.) \*\* BTW I do NOT recomond this!! injury would result)\*\* BTW you should always make the last connection with jumper cables to the engine away from the battery. Batteries generate Hydrogen gas when charging and a spark near them can cause an explosion. **Muldoon** A fluorescent lantern bulb does not start on 12V. The electronic ballast has a circuit that kicks the voltage up (I tried to find out by how much, I could find a link that gave numbers) Anyway you are getting more than 12V when you stick your finger down there. _This does not mean that in the real world a bigger battery doesn’t have advantages, it does. Particulary if it is wet or cold the engine can crank longer before the battery goes dead. This is a good thing as it may get you started._\* ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [February 8, 2003, 5:43am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/31 "2003-02-08T05:43:04Z")
Yeah, okay, I believe you. I actually did study the relationship between current, voltage, and amps. Not that I understood it. But you could all PROVE me wrong by doing the experiment. If you don’t want to touch lead, then use copper wires attached to the poles that you then attach to your tongue. If you do that then…well, then I’ll lick a toad that is reputed to cause hallucinations. But be honest now. I hate the smell of algae. ---
**Author:** ![hammerbach](https://avatars.discourse-cdn.com/v4/letter/h/73ab20/32.png) [@hammerbach](https://boards.straightdope.com/u/hammerbach)\ **Post date:** [February 8, 2003, 5:53am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/32 "2003-02-08T05:53:49Z")
You know, **Rick** , a lot of people really DO think the motor will turn faster, or maybe burn up. I just put a car battery in my sidecar rig, and MANY people have asked my how I keep it from exploding, burning up, or otherwise self destructing. I explain it to them as you did, and they walk away thinking I’m crazy. But thanks for trying… (sigh). ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [February 8, 2003, 5:54am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/33 "2003-02-08T05:54:58Z")
> [@](#): > > \*Originally posted by FranticMad \* > \*\*But you could all PROVE me wrong by doing the experiment. If you don’t want to touch lead, then use copper wires attached to the poles that you then attach to your tongue. If you do that then…well, then I’ll lick a toad that is reputed to cause hallucinations. But be honest now. I hate the smell of algae. \*\* I just tried it. I could barely feel a tingle. It was certainly much less than the effect of a 9V battery. Better go catch your _Bufo marinus_ and start licking. ---
**Author:** ![donkeyoatey](https://avatars.discourse-cdn.com/v4/letter/d/e47c2d/32.png) [@donkeyoatey](https://boards.straightdope.com/u/donkeyoatey)\ **Post date:** [February 8, 2003, 6:53am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/34 "2003-02-08T06:53:22Z")
Be careful how you [experiment with dc batteries](http://www.darwinawards.com/darwin/darwin1999-50.html). :eek: > [@](#): > > A US Navy safety publication describes injuries incurred while doing don’t’s. One page described the fate of a sailor playing with a multimeter in an unauthorized manner. He was curious about the resistance level of the human body. He had a Simpson 260 multimeter, a small unit powered by a 9-volt battery. That may not seem powerful enough to be dangerous… but it can be deadly in the wrong hands. As **Crafter\_Man** said, breaks in the skin are bad. But I still wouldn’t touch a car battery’s positive post while grounded. ---
**Author:** ![donkeyoatey](https://avatars.discourse-cdn.com/v4/letter/d/e47c2d/32.png) [@donkeyoatey](https://boards.straightdope.com/u/donkeyoatey)\ **Post date:** [February 8, 2003, 7:16am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/35 "2003-02-08T07:16:28Z")
The chart on [this page](http://www.ehbc.ca/resources/electricity.html) says the shock from a car battery would be between “Shock - not painful and no loss of muscular control” and “Painful shock - muscular control lost by 50%”. I used 14v/500ohms=28 milliamps. Certainly could be dangerous. > [@](#): > > Playing with DC currents usually causes a single twitch and is considered less dangerous at lower voltage levels than AC circuits. On average, most females have a ‘let go’ limit of 6 - 10 milliamps. Most males have a ‘let go’ limit of 9 - 15 milliamps. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [February 8, 2003, 11:03am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/36 "2003-02-08T11:03:06Z")
Okay. I’ve done further testing. Voltage = 13.2 Volts. Current with both probes on my tongue = 4 milliamps. (Can definitely feel that, worse than the 9 Volt battery on the tongue. Current with one probe on tongue, other on dry skin = 0.1 milliamps. Can hardly feel it. Current with one probe on tongue, other on wet skin = 0.3 millamps. Can feel that. Current with one probe on tongue, other on broken skin = 2 milliamps. **I don’t recommend anyone else try this one. It caused (minor) muscular tremor in my arm, and caused flicker in vision**. I didn’t even realise that I had a cut on my finger, this was an accidental test. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [February 8, 2003, 11:06am UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/37 "2003-02-08T11:06:03Z")
I mean, I didn’t know beforehand that I had a cut on my finger. ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [February 8, 2003, 3:13pm UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/38 "2003-02-08T15:13:55Z")
> [@](#): > > \*Originally posted by Desmostylus \* > \*\*Current with one probe on tongue, other on wet skin = 0.3 millamps. Can feel that. > \*\* Alright. FINE. Where do I find one of those toads? ---
**Author:** ![bruntilda](https://avatars.discourse-cdn.com/v4/letter/b/8dc957/32.png) [@bruntilda](https://boards.straightdope.com/u/bruntilda)\ **Post date:** [February 8, 2003, 4:01pm UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/39 "2003-02-08T16:01:13Z")
**Desmostylus:** It can be very dangerous applying voltages accross a large part of your body. Licking a car battery wouldn’t likely do much except hurt like hell. Grabbing a node with each hand is much more dangerous, because even though the current is smaller, it passes directly over your heart. Or in your case, through your head. ---
**Author:** ![Supernate](https://avatars.discourse-cdn.com/v4/letter/s/ecc23a/32.png) [@Supernate](https://boards.straightdope.com/u/Supernate)\ **Post date:** [February 8, 2003, 4:19pm UTC](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545/40 "2003-02-08T16:19:41Z")
> [@](#): > > Current capability doesn’t matter. I may be taking what you are saying the wrong way… I hope you are saying that the lower the resistance, the more current will flow through the body so it is the resistance that matters, not the current. I think any EE will tell you that current is the ONLY thing that matters as far as safety with electricity is concerned. Some might think that a shock of 10,000V would be more deadly than a shock of 100V, which simply isn’t true. It is the actual current, not the voltage that make it deadly. In fact, currents between 100mA and 200mA can be lethal. [Previous page](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545.md?page=1) [Next page](https://boards.straightdope.com/t/why-dont-i-get-shocked-by-batteries/153545.md?page=3)