2. Strip each wire exposing one inch of copper wire on one end and one half of an inch on the other end.
3. Wrap and secure the one inch side of the stripped copper wire to a galvanized nail. Repeat this process until all wires are connected to one nail each.
4. Lay all of the "cells" out onto the surface leaving about one inch in between each copper and zinc gap. Make sure to alternate the cells so that a zinc tip is always facing a copper tip.
5. Pour 100 ml of the lemon juice concentrate into the flat-bottomed dish.
6. Fold each paper towel until it is approximately two square inches. Thickness is unimportant.
7. Next soak each paper towel in the dish of lemon juice until they are saturated.
8. Then place the paper towels under each zinc and copper gaps and fold the paper towel over the top and press down firmly.
9. Place the glass panes over each paper towel in order to maintain pressure and a closed circuit.
10. Attach the alligator clips to the end of the circuit with the red end of the voltmeter connected to the open copper wire and the black end of the voltmeter connected to the open galvanized nail.
11. The battery should now look like this battery.
12. When you turn the voltmeter on to the 20 volt position, it should read at approximately nine volts.