Tin Foil Battery

You can power a calculator with a simple battery made from tin foil, cardboard and copper pennies. It works in a similar way to a copper and zinc battery stack.

Tin Foil (Aluminum foil)

Cardboard

4 Copper pennies (Pre 1984 if possible, but not required)

White vinegar

Calculator

Hook up wire

• Cut out some discs from the aluminum foil the same size as the copper pennies, I had folded the foil over twice before cutting and this made for thicker discs which were easier to handle.
• Cut out the same number of cardboard discs. Make these just slightly larger than the the aluminum discs or copper pennies.

Soak the cardboard discs in vinegar for a couple of minutes.

Sandwich a cardboard disc between an aluminum disc and a copper penny to make a 'cell'.

Stack one cell on top of the other, with a copper penny touching another cells' aluminum foil, to form a battery.

• Power a calculator with the battery you have created. Connect a wire to the negative on the calculator and connect this wire to outside aluminum disc of the battery. The outside copper penny is connected to the positive of the calculator.
• I found 3 cells could power the calculator I had but this may vary. You may need to use more cells if the pennies you are using were made after 1984 as they are copper plated but they should work well.
• This battery will power a calculator but don't expect it to power your phone as it only generates a fraction of an Amp.