Electric storage device

1. An electric storage device, comprising:

an electric storage cell including a stacked body;

a laminated metal plate having a first metal plate and a second metal plate laminated together so that a surface of the first metal plate is in contact with a surface of the second metal plate, and at least one end portion of each of the first and second plates extends out of the stacked body; and

a potential difference measuring device for measuring potential difference between said first metal plate and said second metal plate outside of the stacked body; wherein said first metal plate and said second metal plate are formed of mutually different metals; and

said laminated metal plate is arranged to be in contact with said electric storage cell.

2. The electric storage device according to claim 1 , comprising a collector plate arranged to be in direct contact with a surface of said electric storage cell; wherein

said collector plate includes said laminated metal plate.

3. The electric storage device according to claim 1 , wherein

the stacked body includes a stack of a plurality of said electric storage cells.

4. The electric storage device according to claim 1 , wherein

said potential difference measuring device includes leads connected to the at least one end portion of said first metal plate and the at least one end portion of said second metal plate, respectively; and

a voltmeter connected to said leads for measuring said potential difference.

5. The electric storage device according to claim 1 , wherein said electric storage cell includes a battery cell.

6. The electric storage device according to claim 1 , comprising a temperature detecting device to detect temperature based on said potential difference.