Just curious about DC voltage

[djjsr]

I was looking at some 48 volt cordless tools and started wondering .......

How high does battery voltage have to be before you can actually feel a shock if you touch both poles?

Anybody know?

 

[Gooch]

I was looking at some 48 volt cordless tools and started wondering .......

How high does battery voltage have to be before you can actually feel a shock if you touch both poles?

Anybody know?

I've felt 12volts before from car batteries.

 

[theoldwizard1]

Somewhere I recall that OSHA standard defined "high voltage" as above 50V.

You can get a good tingle by touching a 9V battery to your tongue !

 

[nehog]

There is no exact answer for that question, skin conductivity and position on the body greatly influences what you will feel.

 

[RPH]

Anything above 25 volts can be dangerous. Anything we build that is the point where safety changes a lot n

 

[G_P]

You can touch both terminals of a battery lightly with dry hands and nothing will be felt.

Grab hard on the terminals or have sweaty hands and youll get a buzz!

 

[e-rockin-it]

For most military and medical specs its 50V. Above that you need special connectors and precautions

 

[D.J.]

Its not the volts that can kill you its the amps if I remember correctly!

 

[laser3kw]

9 volt on your dry arm - nothing. 9 volt on your tongue - tingle.
If I remember right 8 mA cross an open chest during surgery = dead.
I also got a good zap off a car 12 volt, I was hot out and I was sweaty.

 

[sparky36000]

Its not the volts that can kill you its the amps if I remember correctly!

It is, but you need enough voltage to "push" the amps through you

 

[ddawg16]

You can die fr a 9 volt battery.... Depending on what it is hooked up to

 

[nehog]

You can die fr a 9 volt battery.... Depending on what it is hooked up to

Just so people don't panic: this is very, very hard to do. Needs to be directly connected to the heart!

 

[mdd1986]

Its not the volts that can kill you its the amps if I remember correctly!

This not necessarily true. At very high potentials 5,000 volts and above, you can die from arc flash. That is why you see large insulators and arc quenchers at these high voltages.

 

[ddawg16]

Actually....I was thinking more in the order of connecting that 9v battery to a circuit similar to what is in a tazer.....make a few mods to increase the voltage....that should do the trick...

 

[Teken]

People are mistaking some basic elements here. You can have a huge voltage but extremely small current as you see in being zapped from dragging your feet on a carpet.

The amount of electricity to arc over is thousands of volts. No body has ever been killed from a spark from getting out of a car, or carpet.

The famous Tesla coil where sparks of lightning are all over the place and people interact with it are tens of thousands of volts. Again, extremely low current and hence no harmful effect on the user(s).

Introduce a wet environment, or more current.

The end result is a crispy critter on the other end. 25 mA across the heart will stop the heart, as will hitting someone across the chest to cause arrhythmia.

At the end of the day anyone who doesn't believe current will kill and fry you only needs to grab both terminals from a 2, 6, 12 volt battery from a train, scissor lift, solar PV system.

All of the above are very low voltage, but out put 110-2600 amp hours, and instantaneous current of 2000-10000 amps for a short burst.

Teken . . .

 

[djjsr]

Let me simplify it a little.

Let's say I'm not sweating or standing in a puddle or anything out of the ordinary at all.
I can touch both poles of a car battery, an 18 volt cordless drill battery and even my 36 volt lawn mower battery and I don't feel a shock.

Maybe there's electricity flowing but I don't feel it. I don't have a pacemaker or any steel plates, pins, screws, etc in my bones.

I'm thinking that if I touch both poles of a 48 volt cordless tool battery, I may not feel it because it's relatively low amperage, is that right? But if I have four normal car batteries hooked in series (approx. 48 volts) in a golf cart or something, I'd get zapped because it's much higher amperage. Is that right?

 

[sparky36000]

At the end of the day anyone who doesn't believe current will kill and fry you only needs to grab both terminals from a 2, 6, 12 volt battery from a train, scissor lift, solar PV system.

All of the above are very low voltage, but out put 110-2600 amp hours, and instantaneous current of 2000-10000 amps for a short burst.

Teken . . .

You still need enough voltage to push the current through the body. Body resistance can vary greatly with humidity, perspiration, points of contact. So that voltage can vary greatly. But I'll grab both terminals of a 12v lead acid battery all day long. Capable of hundreds of amps, but body resistance is simply to high to cause any harm. I do it all the time in my fishing boat while hooking up my charger. But drop a wrench across a set of parallel deep cycles and watch the fireworks!

 

[sparky36000]

Let me simplify it a little.

Let's say I'm not sweating or standing in a puddle or anything out of the ordinary at all.
I can touch both poles of a car battery, an 18 volt cordless drill battery and even my 36 volt lawn mower battery and I don't feel a shock.

Maybe there's electricity flowing but I don't feel it. I don't have a pacemaker or any steel plates, pins, screws, etc in my bones.

I'm thinking that if I touch both poles of a 48 volt cordless tool battery, I may not feel it because it's relatively low amperage, is that right? But if I have four normal car batteries hooked in series (approx. 48 volts) in a golf cart or something, I'd get zapped because it's much higher amperage. Is that right?

Your 18v cordless battery could provide enough current to kill you, just not enough voltage to push it through you. Assuming conditions aren't absolutely perfect to bring your body resistance down. Now 48v, you might be increasing your odds of getting that 8MA across your heart simply because the voltage is increased, not because of available current. Simple ohms law.

 

[Teken]

Just remember if you have DC voltage / current going through you. More than likely you will not be able to let go of the power source as it will constrict and lock your muscles in place.

I know you're curious and all but I would be very sad to hear you got hurt because you were so curious!

Teken . . .

 

[djjsr]

I know you're curious and all but I would be very sad to hear you got hurt because you were so curious!

Teken . . .

No problem there! I'm just trying to get a better understanding because I see these cordless tool voltages getting higher and I'm wondering if it will eventually become a safety issue.

 

[theoldwizard1]

There is no exact answer for that question, skin conductivity and position on the body greatly influences what you will feel.

That is as good a response as you will get !

 

[sloppy]

No problem there! I'm just trying to get a better understanding because I see these cordless tool voltages getting higher and I'm wondering if it will eventually become a safety issue.

110v AC is present all over the place is that a safety issue? people have used power tools hooked up to 110V for years and under normal use electrical shock is not usually the thing that hurts them..

Just dont put your fingers where they should not be.

 

[mds5951]

Just remember if you have DC voltage / current going through you. More than likely you will not be able to let go of the power source as it will constrict and lock your muscles in place.

I know you're curious and all but I would be very sad to hear you got hurt because you were so curious!

Teken . . .

This IMO is a HUGE factor in the danger... I've heard several stories about people getting "stuck" to dc... Sounds scary as heck

 

[devilsnight]

4 12v battery bank, blew a small chunk off my 9/16 wrench (I remember this as i use the wrench daily!). I've been shocked myself too. it ***** but doesn't compare to getting a guitar string stuck in an outlet on another note though, Im impressed by the amount of energy released by 2 AAA batteries in my wifes "tennis racket" bug zapper. 60K amps i believe. Bees start to smoke and start on fire after 5 seconds. I also truely believe its the amperage that kills you!!

 

[Zelatore]

4 12v battery bank, blew a small chunk off my 9/16 wrench (I remember this as i use the wrench daily!). I've been shocked myself too. it ***** but doesn't compare to getting a guitar string stuck in an outlet on another note though, Im impressed by the amount of energy released by 2 AAA batteries in my wifes "tennis racket" bug zapper. 60K amps i believe. Bees start to smoke and start on fire after 5 seconds. I also truely believe its the amperage that kills you!!

I think you mean 60K volts. Ive never messed with one of those zappers, but if it's actually powere by a pair of AAAs I don't see any way you get that sort of current.

On the battery blowing the end off your wrench, you don't need multiples (serial or parallel) to do that. Arc something across even a small car battery and it can get really ugly! In an instantaneous discharge even little batteries can generate 1000 amps for a second - quite enough to take a chunk out of a wrench or screwdriver if it makes contact right!

 

[nehog]

Actually....I was thinking more in the order of connecting that 9v battery to a circuit similar to what is in a tazer.....make a few mods to increase the voltage....that should do the trick...

Take an old wall wart 120 to 6 volt transformer. Or better, find a bigger transformer (just keep that ratio of 120 volts primary and six volts secondary.)

Connect the secondary (the 6 volt winding) to a 12V source through a normally open push button switch.

Hold the two secondary wires.

Have someone else push the button and release it after about a second.

Report back the results! (If you still feel like typing!)

We used to do that when I was a kid, and dang we'd get a spark almost a 1/4" long from those wires.

 

[KenC]

The most painful shock I've had was from a 12v car system! And, I've been shocked more times than I care to remember. I had wrench on the battery terminal of a starter while leaning over the battery. Hot, sweaty, bare forearm came in really solid contact with the negative post. Same arm that was holding the wrench, with the entire palm and fingers in contact with the wrench. So, about 10-12 inch current path through the sweaty skin and muscle. That muscle was sore for weeks! Felt like a frog leg on the lab table with battery leads attached to make it twitch!