You will need lemon juice, paper towel, five zinc washers and five pennies. Cut the paper towel into nine small squares. The squares should cover a penny without draping over the edge. Soak the pieces in lemon juice. Build a tower by alternating a washer, paper towel, penny and another piece of paper towel until you run out of materials. Dampen your thumb and index finger with water and use them to pick up the tower. You should be able to feel a slight charge from the small battery.
Instead of using only pennies, build a battery out of a variety of coins. Use a voltmeter to determine which combination of coins work best. Write your observations in a journal to help you decide which coins make the best batteries. You can also vary the number of pennies or coins that you use to see if you can change the amount of charge the battery has.
Lemon juice provides the acidic solution needed for a battery to work. Try using other liquids to see if they provide the same results. Soak the paper towels in plain water, salt water or soda water to determine if they will allow a battery to carry a charge. You can also use vinegar or vinegar and salt. Connect your battery to a voltmeter to determine if the type of solution affects the strength of the battery’s voltage.
Make a lemon battery to see if it is stronger or weaker than a penny battery. You will need a fresh lemon, a galvanized zinc nail and a penny. Insert the nail and the penny on opposite ends of the lemon so that they are not touching. Use a voltmeter to determine the strength of the current. You can also conduct an investigation to determine how many penny batteries versus lemon batteries it would take to light an LED light.