Is the Ground of a Car Battery Connected to Any Metal Surface on the Car?

[salman213]

Hey, I was looking at a car and the dealer told me the battery is at the back in the trunk. When he opened the hood he showed me how I would jump it if needed or anything else. He said there is one rod (that was visible coming through a connection from the battery) for the positive and for the ground I would just connect to any metal surface on the car.

Thinking about this can someone explain why the ground can be connected to any metal surface on the car?

I know the ground is just a reference point but is the ground of the battery connected to the metal surface of the car too? How does this make sense..

Thanks!

 

[Astronuc]

Ground is the reference potential with respect to the rest of the circuitry connected to it, and normally, it would refer to the potential of the Earth's surface.

On a car, the negative terminal of the battery is connected to the frame, and that is the reference potential for the electrical system in the car.

 

[salman213]

so by touching the battery's positive terminal and the metal surface can and individual get electrocuted?

 

[turbo]

so by touching the battery's positive terminal and the metal surface can and individual get electrocuted?

a potential of 12V isn't going to do much to you because your body is quite resistive. What the salesman apparently did not make clear enough is that when charging a battery or jumping a battery from another vehicle, the battery can be emitting hydrogen gas. Therefor it is safer to connect to the positive terminal first, then attach the other lead to a grounded metal part a bit distant from the battery. When the battery is charged up (or the vehicle is jump-started) the lead to ground should be removed first, and then the lead to the positive terminal. The ensures that if there is a spark upon connect/disconnect, the spark occurs some distance away from the battery.

 

[waht]

so by touching the battery's positive terminal and the metal surface can and individual get electrocuted?

Current will flow through your body, but not enough to feel it.

 

[salman213]

Okay thank you to all replies