Home Store Project Ideas Project Guide Ask An Expert Blog Careers Teachers Parents Students

A Battery That Makes Cents

Time Required Very Short (≤ 1 day)
Prerequisites None
Material Availability Readily available
Cost Very Low (under $20)
Safety No issues


Batteries are expensive, but you can make one for exactly 24 cents! In this experiment, you will make your own voltaic pile using pennies and nickels. How many coins in the pile will make the most electricity?


In this experiment, you will make a simple battery out of coins and test if the number of coins in the pile will affect the amount of electricity produced.


Sara Agee, Ph.D., Science Buddies

  • StyrofoamTM is a registered trademark of The Dow Chemical Company.

Cite This Page

MLA Style

Science Buddies Staff. "A Battery That Makes Cents" Science Buddies. Science Buddies, 6 Oct. 2014. Web. 31 Oct. 2014 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Energy_p015.shtml>

APA Style

Science Buddies Staff. (2014, October 6). A Battery That Makes Cents. Retrieved October 31, 2014 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/Energy_p015.shtml

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Last edit date: 2014-10-06


You might think that batteries are a modern invention, but batteries were one of the first ways of making electricity. Alessandro Volta discovered the first electric battery in 1800. He made a giant stack of alternating layers of zinc, blotting paper soaked in salt water, and silver. This early design for a battery became known as the voltaic pile.

Physics Project Idea - voltaic pile

This image shows the structure of a voltaic pile, which is the first design of a battery that's used to make electricity. It was discovered by Alessandro Volta in 1800. (HowStuffWorks.com, 2007.)

How does a voltaic pile make electricity? The key to electricity is the movement of electrons. In a voltaic pile, electrons move from one metal to the other through the saltwater solution. The saltwater solution is called an electrolyte, and it contains ions in solution from the dissolved salts. An ion is a group of atoms that carries a positive or negative electric charge. The ions react with the metals, causing an electrochemical reaction, a special kind of chemical reaction that makes electrons.

The two types of metals in a voltaic pile are called electrodes. Since there are two kinds of metals, one metal reacts more strongly than the other, which leaves an electrical potential difference, also called (voltage,) between the two types of metals. One metal becomes positively charged (the positive electrode) and the other becomes negatively charged (the negative electrode). This causes electrons to move, creating an electrical current (which is measured in amperes), and then you have electricity!

In this experiment, you will make your own version of the voltaic pile using two different types of coins and a salt-vinegar solution. How does a voltaic pile made of money work? Since each coin is made up of a different metal, one metal reacts more strongly than the other, which leaves an electrical potential difference (voltage) between the two types of metals. The question is, how will different numbers of coins affect the amount of electricity produced? By making piles with different numbers of coins and measuring the voltage and current produced, you can test the effect of changing the number of coins in the piles

Terms and Concepts

To do this type of experiment, you should know what the following terms mean. Have an adult help you search the Internet or take you to your local library to find out more!

  • Electron
  • Electrolyte
  • Ions
  • Electrochemical reaction
  • Electrode
  • Voltage
  • Current


  • What materials can a battery be made out of?
  • Why is it important for the materials to be arranged in alternating layers?
  • What does the electrolyte solution do?
  • Will more layers make a more or less powerful homemade battery?


Materials and Equipment

  • Pennies (4)
  • Nickels (4)
  • Mild dish soap
  • Vinegar (any kind, 1/4 C.)
  • Salt (1 Tbsp.)
  • Small bowl
  • Small plate (ceramic, plastic, or StyrofoamTM; not paper or metal)
  • Digital multimeter (any kind that reads mA and mV), available at Amazon.com
  • Paper towels (2)
  • Scissors

Disclaimer: Science Buddies occasionally provides information (such as part numbers, supplier names, and supplier weblinks) to assist our users in locating specialty items for individual projects. The information is provided solely as a convenience to our users. We do our best to make sure that part numbers and descriptions are accurate when first listed. However, since part numbers do change as items are obsoleted or improved, please send us an email if you run across any parts that are no longer available. We also do our best to make sure that any listed supplier provides prompt, courteous service. Science Buddies does participate in affiliate programs with Amazon.comsciencebuddies, Carolina Biological, and AquaPhoenix Education. Proceeds from the affiliate programs help support Science Buddies, a 501( c ) 3 public charity. If you have any comments (positive or negative) related to purchases you've made for science fair projects from recommendations on our site, please let us know. Write to us at scibuddy@sciencebuddies.org.

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Experimental Procedure

  1. In a small bowl, mix together 1/4 C. of vinegar (electrolyte) and 1 Tbsp. of salt (ions).
  2. Using scissors, cut up a paper towel into small squares, each approximately 1 cm x 1 cm.
  3. Place the small squares to soak in the bowl of salt-vinegar solution, and set them aside.
  4. Gather some pennies and nickels, wash with a mild detergent (like dish soap), and dry. This is just a preliminary step to remove dirt and grime.
  5. Start building your stack on a dry paper towel on your plate. Put down a penny first, then place a square of vinegar-soaked paper towel on top, and then add a nickel. Keep repeating the layers until you have a stack of four coins (alternating pennies, wet paper towel pieces, and nickels), making sure you end with a nickel on top.
  6. Attach the leads of the multimeter to the two ends of the battery by touching one lead to the penny on the bottom and the other to the nickel on the top. Measure the voltage produced by your battery (in millivolts, mV). You can also measure the current produced (in milliamps, mA).
  7. Repeat the experiment, each time building a battery with a different number of coins. One important rule is to always start with a penny and end in a nickel, so the number of layers of pennies and nickels will always match. Why do you think this is necessary?
  8. Record your data in a data table like the one below:
    Number of pennies Number of nickels Voltage (mV) Current (mA)
  9. Make a graph of your data. What trends do you observe?

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.


  • Try connecting an LED to your battery with copper wire. Be sure the wire is NOT enameled, or it will not work! How many coins do you need to light the light? You can test different LEDs to see if they need the same number of coins to light up. (LEDs only pass current in one direction, so be sure you have it oriented correctly.)
  • Compare different coin combinations to see which ones work and which ones don't:
    • Penny - Dime
    • Nickel - Dime
    • Nickel - Quarter
    • Penny - Quarter
  • Try other electrolyte solutions to see which ones work and which ones don't:
    • Plain water
    • Salt water
    • Lemon juice
    • Soda water
  • Try making batteries out of other things, like potatoes or fruits. Try the Science Buddies experiment Potato Batteries: How to Turn Produce into Veggie Power! for more ideas!

Share your story with Science Buddies!

I did this project I Did This Project! Please log in and let us know how things went.

Ask an Expert

The Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.

Ask an Expert

Related Links

If you like this project, you might enjoy exploring these related careers:

Two electricians working.


Electricians are the people who bring electricity to our homes, schools, businesses, public spaces, and streets—lighting up our world, keeping the indoor temperature comfortable, and powering TVs, computers, and all sorts of machines that make life better. Electricians install and maintain the wiring and equipment that carries electricity, and they also fix electrical machines. Read more
female chemical engineer at work

Chemical Engineer

Chemical engineers solve the problems that affect our everyday lives by applying the principles of chemistry. If you enjoy working in a chemistry laboratory and are interested in developing useful products for people, then a career as a chemical engineer might be in your future. Read more
electrical engineer aligning laser

Electrical & Electronics Engineer

Just as a potter forms clay, or a steel worker molds molten steel, electrical and electronics engineers gather and shape electricity and use it to make products that transmit power or transmit information. Electrical and electronics engineers may specialize in one of the millions of products that make or use electricity, like cell phones, electric motors, microwaves, medical instruments, airline navigation system, or handheld games. Read more

Looking for more science fun?

Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.

Find an Activity