can a 9- volt battery cause electric shock and death?
By tippiness
@tippiness (23)
Philippines
April 20, 2012 10:01pm CST
I've been taught in our nursing classes that even 1 volt could kill and cause fibrillation to the heart. But then, my boyfriend who is a computer engineer continues to argue with me about the difference of an alternative current (AC) and Direct current (DC). In which, battery is an example of a DC, and by that it means that it cannot cause electric shock and death regardless of the electrical resistance of a person.
I need other views on this. I'm really confused!
2 responses
@BrainySaber (32)
• India
30 Aug 15
Theoretically, considering a 9V battery is powering a thick, small wire with the net resistance extremely close to one ohm (wire's resistance considered to be extremely close to zero and the internal resistance is considered to be extremely close to 1 (got this info off the net. Search "internal resistance of 9V battery" and it can be 1 or 2 ohm, so for simplicity I assumed it to be extremely close to 1 ohm)) and it is connected to someone's heart, the current flowing through it will be extremely close to 9A which is A LOT of current and it will easily kill the human. But of course all that is theory. Practically speaking, the resistance of skin is quite high...so is the resistance of blood, thus it obviously won't be enough to kill a person.
Also, a 9V battery contains poisonous stuff in it so I guess if you put it enough times in your mouth then it will obviously be lethal. That's just me guessing tho. You'll know better. :)
As @owlwings has said, it is the current that matters, not the voltage. "I" will kill you, "V" won't.
Hope this helps! :D
@owlwings (43910)
• Cambridge, England
21 Apr 12
The natural electrical resistance of the body and the internal resistance of the battery means that a 9 volt battery could not deliver enough current to cause fibrillation or do any harm. If you touch the two contacts of a 9 volt battery to your tongue you get a sharp tingling sensation but that is all (in fact, that is how I commonly test whether a battery is good or not).
It is not the voltage that matters but the current. If you have a low voltage but a very high current, that could certainly be dangerous. To understand how it works, you need to understand Ohm's Law which says that the current flowing in a circuit is proportional to the voltage and inversely proportional to the resistance. Since a 9 volt battery already has quite a high internal resistance, it cannot ever (by itself) deliver enough current to kill a human.
@tippiness (23)
• Philippines
21 Apr 12
great! now i lost the bargain.haha. thank you guys! but what if it's a baby? can this battery be dangerous?
1 person likes this
@owlwings (43910)
• Cambridge, England
21 Apr 12
No, a baby wouldn't be electrocuted by a 9 volt battery. I think that it might make a very tiny frog jump quite high, perhaps 
You can get quite a nasty jolt from a car battery (12 volts but capable of delivering a far higher current) and it's definitely not a good idea to experience mains current from one arm to the other (the current is then likely to go through the heart). I have known one or two electricians, however, who test for a live socket with a finger. They make sure that their hand is dry and they also NEVER use both hands.
You can get quite a nasty jolt from a car battery (12 volts but capable of delivering a far higher current) and it's definitely not a good idea to experience mains current from one arm to the other (the current is then likely to go through the heart). I have known one or two electricians, however, who test for a live socket with a finger. They make sure that their hand is dry and they also NEVER use both hands.@owlwings (43910)
• Cambridge, England
22 Apr 12
Without knowing more details about the case, it's impossible to comment. I think it would be a rather exceptional and unusual incident and the diagnosis of 'electrocution' may not be the whole story.
