# Change in potential of terminals of batteries

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1. Jun 2, 2015

### Vishwas D

I know there will be potential difference between the terminals of a battery. But when the positive terminal of a battery is connected to the negative terminal of another, will both of the connected terminals achieve the same potential? If so, what happens to the individual potential differences of the batteries?

2. Jun 2, 2015

### jerromyjon

There is zero potential between the negative of one battery and the positive of another. Absolutely nothing occurs without a circuit between the remaining terminals.

3. Jun 2, 2015

### Staff: Mentor

Hi Vishwas D.

When points are connected together by wire having low or zero resistance, they become the same potential. There can consequently not exist any potential difference between those connected points.

When connected in series as you describe, each individual cell continues to present exactly the same potential difference between its two terminals as before; not a thing has changed as far as any of the individual cells is concerned.

4. Jun 3, 2015

### Vishwas D

But when the connected terminals achieve the same potential, The common potential of those terminals will be different from the original right? Then how do the individual potential drops remain same?

5. Jun 3, 2015

### jerromyjon

A single battery terminal has 0VDC potential. You can connect + on one battery and + on another and it will not short the batteries unless you connect the - terminals. A battery is not a storehouse of electrons that flow like water from a hose, electrons have to drift into the negative terminal for the chemical reaction inside the battery to maintain the potential, which can only be realized in a complete circuit.

6. Jun 3, 2015

### CWatters

Consider two 12V batteries with the +ve of one connected to the -ve of the other. The potential difference between the other terminals will be 24V.

It is possible to define any of the terminals as a reference 0V. Depending on which you choose you can generate...

0 +12 +24
-12 0 +12
-24 -12 0

Last edited by a moderator: Jun 3, 2015
7. Jun 3, 2015

### Staff: Mentor

The 'original potential' of a battery's terminals is unknown/undefined/unspecified if it is not connected to anything. All you can say about an isolated battery sitting by itself is that there exists a known potential difference across its terminals.

8. Jun 3, 2015

### stedwards

[deleted]

Last edited: Jun 3, 2015