Raw potato battery
||3 Zn + 2 H3PO4→Zn3 (PO4 )2 + 3 H2
|Internal charge carrier
||6 H + + 6 e-→3 H2
||3 Zn + 2 H3PO4→Zn3 (PO4 )2 + 6 H + + 6 e-
A simple source of electrochemical power requiring only zinc, copper and potatos.
- This reaction makes the potato toxic: it will contain measurable amounts of zinc phosphate along with smaller amounts of other zinc and copper compounds. These are even more toxic to fish than humans, so dispose of the used potato (without the metal strips) in a fire.
- A copper strip approximately 2-3cm wide by 10-15cm long by 0.5-2mm thick.
- A zinc strip of the same dimentions
- A potato
- Push the copper strip a few cm deep into one end of the potato. If the potato is longer along one axis, insert the strip so that it is perpendicular to that axis.
- Push the zinc strip a few cm deep into one end of the potato. Likewise, if the potato is longer along one axis, insert the strip so that it is perpendicular to that axis.
- Measure the voltage potential between the strips. It should be more than 0.25 but less than 1.15 volts.
- Measure the short-circuit current between the strips. It should be between 0.1 and 10 mA.