# I How does a battery push charges? Potential difference?

1. May 17, 2017

### Notaphysicsmajor

Hello there,

I'm confused on several things such as the potential difference it provides and how it pushes the charges through the wire or conductor or circuit.

So when a battery comes into contact with a wire, the positive charges flows from high potential through the circuit to the low potential. If I understood it correctly, it basically means the charges from the top of the battery flow through the circuit to get to the bottom of the battery, is this correct?

But how is it exactly doing this? Conceptually I'm not getting it and I'd rather understand it instead of simply believing it so.

The confusion I'm having is with potential difference. I thought it was the electric force providing the force to push charges. How exactly is the potential difference and electric field difference? I understand that the potential difference is scalar and electric field is a vector, but how does the potential difference from a battery provide the force, if I can call it that, to push charges?

2. May 17, 2017

### Orodruin

Staff Emeritus
The electric field is the negative of the gradient of the electric potential ...

3. May 17, 2017

### scottdave

This may confuse you more, but you wanted to know what is happening. First of all. The actual operation of electric current through a wire is via electrons. Electrons have a negative charge. The negative terminal of a battery has ions which have excess electrons, so it has a negative charge. The positive terminal has ions which are missing some electrons, giving it a positive charge (each ion has more protons than electrons). So when a circuit is hooked up, you have the positive charge starts attracting electrons from the wire, and the negative charge starts repelling electrons into the wire.
The net effect is that electrons flow from the negative terminal, through the circuit to the positive terminal.

But the convention is that 'positive charges' flow from the positive terminal toward the negative. The net effect of negatively charged electrons moving up is the same, though.
I hope this helps.

4. May 17, 2017

### Notaphysicsmajor

Hi Scottdave

I'm sorry I forgot to imply that it is actually that the negative charges that are moving, although use positive charges for easier demonstration.

Based on what you said, what exactly is inside the battery then? An imbalance of charges on both ends? Similar to a charge capacitor? Therefore once it's given a path for the electrons to move from high potential (the negative end) to low potential (the positive end) it will then move based on what you said?

5. May 17, 2017

### scottdave

I am going to point you to this Engineerguy video, which does a nice job of explaining