Build a Battery Challenge
Concepts explored:
• Engineering Design Process
• Electrical Engineering
• Batteries
Scenario:
In 1799, Italian physicist Alessandro Volta created the first battery by stacking alternating layers
of zinc, brine-soaked pasteboard or cloth, and silver. This arrangement, called a voltaic pile, was
not the first device to create electricity, but it was the first to emit a steady, lasting current.
However, there were some drawbacks to Volta's invention. The height at which the layers could
be stacked was limited because the weight of the pile would squeeze the brine out of the
pasteboard or cloth. The metal discs also tended to corrode quickly, shortening the life of the
battery. Despite these shortcomings, the unit of electromotive force is now called a volt in honor
of Volta's achievement. (Adapted from How Stuff Works)
Materials:
(Per person)
• 6 pennies
• 6 zinc washers
• 1 notecard
• 1 bowl of salt water
• Scissors
• Foil
• Wire with alligator clip ends
• Foil
• Safety Glasses
• LED light
Problem:
Can you recreate Alessandro Volta’s invention of the Voltaic pile battery?
Task:
To follow Volta’s directions to create a similar voltaic pile battery that turns on an LED.
Constraints:
• Must light up the LED
• Must only use the supplies given
• Must be constructed in the 30 minutes given
Facilitation Plan:
Students will get basic direct instruction on batteries and how batteries work. Students will
then have scenario, problem, task, and constraints detailed to them. Materials will be
distributed. The teacher will then walk students through the battery build, step by step with
students following along. First, students will cut six circles out of the index cards, with each
circle being the same size as a penny. Next students will soak the index cards in the salt water.
While these are soaking, a penny will be placed on the foil. On top of this, a circle from the salt
water will be placed on top of the penny. Next a zinc washer will be placed on top of the salt
water soaked paper circle. This pattern will continue with another penny, paper, and washer on
top of the existing stack until all of the penny, washer, and soaked circle supplies are used up and
placed in a large stack. The wire is then used with one alligator clip clipped to the foil and the
other alligator clip clipped to the long leg of the LED. To light up the LED, simply touch the
short leg to the top of the pile. NOTE: if it does not light up, the pile may need more voltaic
piles or may need to be better stacked.