OK, I love car audio, but hate (and am scared of) batteries, or power in general (including caps).
My theory is that if I'm touching the negative terminal to disconnect it, and if my body is also touching the vehicle anywhere (legs on the bumper), what's stopping the power from going through me?
Also, what if I'm touching a power wire, and am also touching the metal of the vehicle, even thought the negative wire is disconnected, couldn't the power go from the positive terminal through me to the body of the vehicle (ground is ground world round)?
I know I could just take the batterie out completely, but (of course) I'm wondering if I will get shocked when I touch the positive terminal after disconnecting the negative, thinking that if my feet are grounded, power will go through me like I'm just a big resistor.
OK, let me explain why I get so paranoid:
I was taking a batterie out of a '72 Pontiac Ventura when I felt a tingling feeling in my thighs which were touching the bumper. I also touched an electric horse fence once when I was like 12 or so.
Well, that's all it took and I've been afraid of power ever since. My heart starts racing whenever I touch anything that could be connected to power.
Replies (4)
Munchiesyumm on 01/14/2004 19:46:57
power can be somewhat scary. It is a shocking feeling that scares you more, it goesn't nessisarily hurt but it makes things feel strange.
You shouldn't have a problem disconnecting the battery terminals. Postive first than Negitive. I don't see how you could get shocked by touching them unless you like really try. Take the positive battery terminal cover it up in the plastic cover many batteries have and set it down in a safe spot and no troubles.
Jebus on 01/14/2004 19:19:22
While a healthy fear of electricity is a great thing to keep yourself alive, you do not have to be so scared. I was the team leader for an electric car (12 12v car batteries in series - 144v dc!) team for four years and lived to tell the tale.
If you are touching the negative terminal and also the body of the car, you have nothing to worry about, because the electricity only flows from positive to negative. Since when the battery is hooked up the body of the car is like a big negative terminal, there is nothing to worry about: Your hand on terminal - negative, car body - negative, no flow.
There will only be flow of electricity if the positive terminal or a positive wire touches the negative terminal, negative wire, or the car body.
If the negative terminal is disconnected, there is no chance of flow from the body to the positive terminal. This is because the body is conected to the negative bettery terminal through the wire that you have already disconnected. The vehicle body is grounded to the battery by design of the manufacturer, not incidentally, so after you remove the negative connection, the body becomes just another hunk of metal.
If you touch the positive terminal, nothing will happen until you touch the negative. Although your feet are "grounded" by way of touching the ground, there is not near enough charge in the battery to move through you into the earth. It takes something like lightning (100,000+ v) or a high voltage power line (10,000+ v) to overcome the resistance of your body.
Also, not to imply that you should not be a little scared, but DRY skin has about 1,000,000 ohms of resistance. Since electricity always takes the path of least resistance, it really does not want to go through your body. Of course sweaty or wet skin has less, so no resistor imitations:)
Another thing that could help assuage your fears when working with electricity is to use one hand whenever you are doing something that worries you. It is not inherintly a bad thing to get shocked, electricity only kills or damages you when it flows through certain places, especially your heart. By using only one hand in places where it seems likely that you will be shocked you will keep current from flowing through your heart. I have had one or the other of my hands shocked many times when working on the electric car, to no result other than a mild tingle.
Lastly, you must discharge your capacitor after disconnecting the battery. This is now the only item in the car that can do you any electrical harm. This can be done very safely by hooking two multimeter probe wires or any insulated wire to a lightbulb and touching the terminals of the cap with them. When the light goes out, the cap is dry of electrons. Even if you hold one wire in each hand, keep in mind that a 100W indoor light bulb has about 100 ohms of resistance, and your (DRY) skin have 10,000 times that.
Once again, the easiest way to protect yourself when in electrical danger is by working with one hand!
alanjlamore on 01/14/2004 19:59:05
Thanks!
I have yet to re-wire my system from a problem I talked about here a lot of posts ago!
I got a lot of help about the problem, but have been hesitant to re-run my wires and fix my grounds.
I'm almost sure I can fix the problem (amps keep cutting out), but I've been waiting for a friend of mine to do the batterie stuff. It snowed on the day we planned to do it and he has a busy schedule, but I think I can try it on my own now.
Thanks again,
Alan
uochronos on 01/14/2004 22:15:24
I wouldnt be afraid too much of your battery just use the common electrical since always unhook the terminals carefully use rubber gloves if your really nervous. dont touch any metal while touching the positive... and always unhook the positive cable from the battery before working on your systems power... i recently made the mistake of re running my power wire to my amp without unhooking it to say the least i touched the end of the wire and my clutch pedal at the same time and arched quite a bit and sent the power threw my hand(blew an 80 amp fuse) and it didnt really even hurt just tingled really bad and threw my hand back.. so as long as you dont get overly brave(stupid) like me you should be fine and have nothing to worry about. with your seeming fear though i would suggest some rubber gloves. as in the surgucal type you can still move easy in and then you have no worries at all..
My theory is that if I'm touching the negative terminal to disconnect it, and if my body is also touching the vehicle anywhere (legs on the bumper), what's stopping the power from going through me?
Also, what if I'm touching a power wire, and am also touching the metal of the vehicle, even thought the negative wire is disconnected, couldn't the power go from the positive terminal through me to the body of the vehicle (ground is ground world round)?
I know I could just take the batterie out completely, but (of course) I'm wondering if I will get shocked when I touch the positive terminal after disconnecting the negative, thinking that if my feet are grounded, power will go through me like I'm just a big resistor.
OK, let me explain why I get so paranoid:
I was taking a batterie out of a '72 Pontiac Ventura when I felt a tingling feeling in my thighs which were touching the bumper. I also touched an electric horse fence once when I was like 12 or so.
Well, that's all it took and I've been afraid of power ever since. My heart starts racing whenever I touch anything that could be connected to power.
Replies (4)
Munchiesyumm on 01/14/2004 19:46:57
power can be somewhat scary. It is a shocking feeling that scares you more, it goesn't nessisarily hurt but it makes things feel strange.
You shouldn't have a problem disconnecting the battery terminals. Postive first than Negitive. I don't see how you could get shocked by touching them unless you like really try. Take the positive battery terminal cover it up in the plastic cover many batteries have and set it down in a safe spot and no troubles.
Jebus on 01/14/2004 19:19:22
While a healthy fear of electricity is a great thing to keep yourself alive, you do not have to be so scared. I was the team leader for an electric car (12 12v car batteries in series - 144v dc!) team for four years and lived to tell the tale.
If you are touching the negative terminal and also the body of the car, you have nothing to worry about, because the electricity only flows from positive to negative. Since when the battery is hooked up the body of the car is like a big negative terminal, there is nothing to worry about: Your hand on terminal - negative, car body - negative, no flow.
There will only be flow of electricity if the positive terminal or a positive wire touches the negative terminal, negative wire, or the car body.
If the negative terminal is disconnected, there is no chance of flow from the body to the positive terminal. This is because the body is conected to the negative bettery terminal through the wire that you have already disconnected. The vehicle body is grounded to the battery by design of the manufacturer, not incidentally, so after you remove the negative connection, the body becomes just another hunk of metal.
If you touch the positive terminal, nothing will happen until you touch the negative. Although your feet are "grounded" by way of touching the ground, there is not near enough charge in the battery to move through you into the earth. It takes something like lightning (100,000+ v) or a high voltage power line (10,000+ v) to overcome the resistance of your body.
Also, not to imply that you should not be a little scared, but DRY skin has about 1,000,000 ohms of resistance. Since electricity always takes the path of least resistance, it really does not want to go through your body. Of course sweaty or wet skin has less, so no resistor imitations:)
Another thing that could help assuage your fears when working with electricity is to use one hand whenever you are doing something that worries you. It is not inherintly a bad thing to get shocked, electricity only kills or damages you when it flows through certain places, especially your heart. By using only one hand in places where it seems likely that you will be shocked you will keep current from flowing through your heart. I have had one or the other of my hands shocked many times when working on the electric car, to no result other than a mild tingle.
Lastly, you must discharge your capacitor after disconnecting the battery. This is now the only item in the car that can do you any electrical harm. This can be done very safely by hooking two multimeter probe wires or any insulated wire to a lightbulb and touching the terminals of the cap with them. When the light goes out, the cap is dry of electrons. Even if you hold one wire in each hand, keep in mind that a 100W indoor light bulb has about 100 ohms of resistance, and your (DRY) skin have 10,000 times that.
Once again, the easiest way to protect yourself when in electrical danger is by working with one hand!
alanjlamore on 01/14/2004 19:59:05
Thanks!
I have yet to re-wire my system from a problem I talked about here a lot of posts ago!
I got a lot of help about the problem, but have been hesitant to re-run my wires and fix my grounds.
I'm almost sure I can fix the problem (amps keep cutting out), but I've been waiting for a friend of mine to do the batterie stuff. It snowed on the day we planned to do it and he has a busy schedule, but I think I can try it on my own now.
Thanks again,
Alan
uochronos on 01/14/2004 22:15:24
I wouldnt be afraid too much of your battery just use the common electrical since always unhook the terminals carefully use rubber gloves if your really nervous. dont touch any metal while touching the positive... and always unhook the positive cable from the battery before working on your systems power... i recently made the mistake of re running my power wire to my amp without unhooking it to say the least i touched the end of the wire and my clutch pedal at the same time and arched quite a bit and sent the power threw my hand(blew an 80 amp fuse) and it didnt really even hurt just tingled really bad and threw my hand back.. so as long as you dont get overly brave(stupid) like me you should be fine and have nothing to worry about. with your seeming fear though i would suggest some rubber gloves. as in the surgucal type you can still move easy in and then you have no worries at all..
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