• Visit
    • Calendar
    • After Dark Thursdays
    • Buy Tickets
    • Exhibits
    • Museum Galleries
    • Artworks on View
    • Hours
    • Getting Here
    • Visitor FAQ
    • Event Rentals
    • Field Trips
  • Education
    • Professional Development Programs
    • Free Educator Workshops
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate Today!
    • Membership
    • Join Our Donor Community
    • Engage Your Business
    • Attend a Fundraiser
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Host Your Event
    • Volunteer
  • Store
  • Visit
    • Frequently Asked Questions
    • Calendar
      • Today
      • This Week
      • Online
      • After Dark Thursday Nights
      • Arts
      • Conferences
      • Cinema Arts
      • Free + Community Events
      • Fundraising Events
      • Kids + Families
      • Members
      • Special Hours
      • Private Event Closures
    • Prices
    • Hours
    • Getting Here
    • Museum Map
    • Free Admission and Reduced Admission
    • Accessibility
    • Tips for Visiting with Kids
    • How to Exploratorium
    • Exhibits
    • Tactile Dome
    • Artworks on View
    • Cinema Arts
    • Kanbar Forum
    • Black Box
    • Museum Galleries
      • Bernard and Barbro Osher Gallery 1: Human Phenomena
        • Tactile Dome
          • 1971 Press Release
        • Black Box
        • Curator Statement
      • Gallery 2: Tinkering
        • Curator Statement
      • Bechtel Gallery 3: Seeing & Reflections
        • Curator Statement
      • Gordon and Betty Moore Gallery 4: Living Systems
        • Curator Statement
      • Gallery 5: Outdoor Exhibits
        • Curator Statement
      • Fisher Bay Observatory Gallery 6: Observing Landscapes
        • Wired Pier Environmental Field Station
        • Curator Statement
    • Restaurant & Café
    • School Field Trips
      • Getting Here
        • Bus Routes for Field Trips and Other Groups
      • Admission and Tickets
      • Planning Guide
      • Reservations
        • Field Trip Request Form
      • Resources
    • Event Rentals
      • Full Facility & Gallery Bundles
      • Fisher Bay Observatory Gallery & Terrace
      • Moore East Gallery
      • Bechtel Central Gallery & Outdoor Gallery
      • Osher West Gallery
      • Kanbar Forum

      • Weddings
      • Proms and School Events
      • Daytime Meetings, Events, & Filmings

      • Rentals FAQ
      • Event Planning Resources
      • Rental Request Form
      • Download Brochure (pdf)
    • Groups / Tour Operators
      • Group Visit Request Form
    • Exploratorium Store
    • Contact Us
  • Education
    • Black Teachers and Students Matter
    • Professional Development Programs
      • Free Educator Workshops
      • Professional Learning Partnerships
      • Teacher Institute
        • About the Teacher Institute
        • Summer Institute for Teachers
        • Teacher Induction Program
        • Leadership Program
        • Teacher Institute Research
        • CA NGSS STEM Conferences
          • NGSS STEM Conference 2020
        • Science Snacks
          • Browse by Subject
          • Special Collections
          • Science Snacks A-Z
          • NGSS Planning Tools
          • Frequently Asked Questions
        • Digital Teaching Boxes
        • Meet the Teacher Institute Staff
        • Resources for Supporting Science Teachers
      • Institute for Inquiry
        • What Is Inquiry?
        • Watch and Do Science
        • Inquiry-based Science and English Language Development
          • Educators Guide
            • Conceptual Overview
              • Science Talk
              • Science Writing
            • Classroom Video Gallery
              • Magnet Investigation
              • Snail Investigation
            • Teacher Professional Development
            • Project Studies
            • Acknowledgments
          • Conference: Exploring Science and English Language Development
            • Interviews with Participants
            • Plenary Sessions
            • Synthesis, Documentation, and Resources
        • Workshops
          • Participant Portal
          • Fundamentals of Inquiry
            • Summary Schedule
          • BaySci Science Champions Academy
          • Facilitators Guides
          • Commissioned Workshops
        • Resource Library
        • Meet the IFI Staff
      • Resources for California Educators
      • K-12 Science Leader Network
      • Resources for Supporting Science Teachers
      • Field Trip Explainer Program
      • Cambio
    • Tools for Teaching and Learning
      • Learning Toolbox
      • Science Snacks
      • Digital Teaching Boxes
      • Science Activities
      • Tinkering Projects
      • Recursos gratuitos para aprender ciencias
      • Videos
      • Exhibits
      • Publications
      • Apps
      • Educator Newsletter
      • Exploratorium Websites
    • Educator Newsletter
    • Advancing Ideas about Learning
      • Visitor Research and Evaluation
        • What we do
        • Reports & Publications
        • Projects
        • Who we are
      • Center for Informal Learning in Schools
    • Community Programs
      • High School Explainer Program
      • Xtech
      • Community Educational Engagement
      • California Tinkering Afterschool Network
        • About
        • Partners
        • Resources
        • News & Updates
        • Further Reading
  • Explore
    • Browse by Subject
      • Arts
      • Astronomy & Space Sciences
        • Planetary Science
        • Space Exploration
      • Biology
        • Anatomy & Physiology
        • Ecology
        • Evolution
        • Genetics
        • Molecular & Cellular Biology
        • Neuroscience
      • Chemistry
        • Combining Matter
        • Food & Cooking
        • Materials & Matter
        • States of Matter
      • Data
        • Data Collection & Analysis
        • Modeling & Simulations
        • Visualization
      • Earth Science
        • Atmosphere
        • Geology
        • Oceans & Water
      • Engineering & Technology
        • Design & Tinkering
        • Real-World Problems & Solutions
      • Environmental Science
        • Global Systems & Cycles
        • Human Impacts
      • History
      • Mathematics
      • Nature of Science
        • Measurement
        • Science as a Process
        • Size & Scale
        • Time
      • Perception
        • Light, Color & Seeing
        • Listening & Hearing
        • Optical Illusions
        • Scent, Smell & Taste
        • Tactile & Touch
      • Physics
        • Electricity & Magnetism
        • Energy
        • Heat & Temperature
        • Light
        • Mechanics
        • Quantum
        • Sound
        • Waves
      • Social Science
        • Culture
        • Language
        • Psychology
        • Sociology
    • Browse by Content Type
      • Activities
      • Blogs
        • Spectrum
          • Arts
          • Behind the Scenes
          • News
          • Education
          • Community & Collaborations
          • Science
        • Eclipse
        • Studio for Public Spaces
        • Tangents
        • Resonance See & Hear Blog
        • Fabricated Realities
        • Tinkering Studio: Sketchpad
        • Exploratorium on Tumblr
      • Exhibits
      • Video
      • Websites
      • Apps
        • Total Solar Eclipse
  • About Us
    • Our Story
    • Land Acknowledgment
    • Explore Our Reach
    • Impact Report
    • Awards
    • Our History
      • 50 Years 1969–2019

    • Senior Leadership
    • Board of Trustees
    • Board of Trustees Alumni
    • Staff Scientists
    • Staff Artists

    • Arts at the Exploratorium
      • Artworks on View
      • Artist-in-Residence Program
      • Cinema Arts
        • History and Collection
        • Cinema Artists-in-Residence
        • Resources and Collaborating Organizations
        • Kanbar Forum
      • Center for Art & Inquiry
        • Begin Here
          • Lessons
            • Bob Miller/Light Walk
            • Ruth Asawa/Milk Carton Sculpture
          • Workshops
      • Resonance
        • About the Series
        • See & Hear
        • Past Seasons
      • Over the Water
      • Black Box
      • Upcoming Events
      • Temporary Exhibitions
      • Arts Program Staff
    • Teacher Institute
    • Institute for Inquiry
    • Explainer Programs
    • Studio for Public Spaces
    • Exhibit Making
    • Partnerships
      • Building Global Connections
        • Global Collaborations
          • Projects
          • Approach
          • People
          • Impact
      • Partnering with Science Agencies
        • NASA
        • NOAA
      • Partnering with Educational Institutions
      • Osher Fellows

    • Job Opportunities
    • Become a Volunteer

    • Contact Info
    • Newsletter
    • Educator Newsletter
    • Blogs
    • Follow & Share
    • Press Office

    • FY21 Audit Report
    • 990 FY20 Tax Return
    • Use Policy
      • Privacy Policy
      • Intellectual Property Policy
  • Join + Support
    • Donate Today!
    • Membership
      • Membership FAQ
      • Member Benefits
      • After Dark Membership
      • Member Events
      • May Is for Members
    • Join Our Donor Community
    • Engage Your Business
      • Corporate Membership
      • Luminary Partnerships
    • Attend a Fundraiser
      • Wonder Funday
      • Science of Cocktails
      • Party at the Piers
        • Event Leadership and Host Committee
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Volunteer
      • How to Apply
      • Application for Internships
      • Our Contract
      • Application for Individuals
  • Press Office
    • Press Releases
    • News Coverage
    • Events Calendar
    • Photographs
    • Press Video
    • Press Kits
    • Press Visits
    • Exploratorium Logos
    • Recent Awards
    • Praise for the Exploratorium
    • Join Our Press List
  • Store

Masks and vaccinations are recommended. Plan your visit  

Visitor FAQ Buy Tickets Donate Today
Exploratorium
Exploratorium
  • Visit
    • Calendar
    • After Dark Thursdays
    • Buy Tickets
    • Exhibits
    • Museum Galleries
    • Artworks on View
    • Hours
    • Getting Here
    • Visitor FAQ
    • Event Rentals
    • Field Trips
  • Education
    • Professional Development Programs
    • Free Educator Workshops
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate Today!
    • Membership
    • Join Our Donor Community
    • Engage Your Business
    • Attend a Fundraiser
    • Explore Our Reach
    • Thank You to Our Supporters
    • Donor & Corporate Member FAQ
    • Host Your Event
    • Volunteer
  • Store
Science Snacks
Science activity that demonstrates the chemistry of a battery

Penny Battery

Light an LED with five cents.

Use two different metals and some sour, salty water to create an inexpensive battery.


Grade Bands: 
3-5
6-8
9-12
Subject: 
Chemistry
Combining Matter
Engineering & Technology
Design & Tinkering
Real-World Problems & Solutions
Physics
Electricity & Magnetism
Light
Keywords: 
LED
video
battery
electron
NGSS and EP&Cs: 
PS
PS1
PS3
ETS
ETS1
CCCs
Cause and Effect
Energy And Matter

  • Facebook logo
  • Reddit logo
  • Twitter logo


Video Demonstration

Penny Battery: Introduction
Penny Battery: Materials and assembly
Penny Battery: What's going on?
Penny Battery: Teaching tips

Tools and Materials

  • Five or more post-1982 U.S. pennies
  • Piece of 100-grit sandpaper
  • Matboard or thick cardboard
  • Salt
  • Vinegar
  • A red LED; high-intensity ones are easier to see
  • Electrical tape
  • A voltmeter
  • Scissors (not shown)
  • Cup with water (not shown)
  • Paper towel (not shown)
  • Optional: other LEDs of different colors, such as yellow and blue

Assembly

  1. Make a saturated salt solution by adding salt to water and stirring until it doesn't dissolve anymore. Add a splash of vinegar to this solution.
  2. Cut your matboard into four 1/2-inch squares, each about the size of a penny. Soak the pieces in the salt-and-vinegar solution. Once the pieces are thoroughly wet, take them out and place them on a paper towel so they are still damp, but not dripping.
  3. Use sandpaper to remove the copper from ONE side of each of four pennies. Leave the fifth penny intact. Sand until you see zinc (shiny silver color) covering the entire face of the coin. This takes some time and effort, so be patient. Try placing the sandpaper on a hard surface and moving the penny instead of the sandpaper. The "tails" side may be easier to sand because the Lincoln Memorial (or Union Shield) doesn't protrude as far as Lincoln's head. When you're done, the sanded coins should have a bronze-colored copper side and a silver-colored zinc side.
     

To Do and Notice

Take one of your sanded pennies with the zinc side facing up (copper side down), and place a damp piece of matboard on it. Then stack another sanded penny (again, zinc side facing up) on top of this. Take your next piece of matboard and place it on top, and continue stacking pennies and matboard on top of each other to make a neat pile. Finally, place the unsanded penny at the very top.

When you're done, you should have alternating layers of pennies and matboard with all the zinc sides facing up, and both the very top and the very bottom of your stack (facing down) should be copper. Make sure the pennies aren't directly touching each other and, likewise, that the pieces of matboard aren't touching each other.

Test your battery by connecting your LED. Touch the longer lead to the intact penny on the top and the shorter lead to the bottom of the stack. Make sure that the leads don't touch any other layer. Did the LED turn on? If not, make sure the LED leads are oriented correctly and use a paper towel to wipe off any excess water from the penny-matboard stack.

Check the voltage of the battery with a voltmeter by placing the leads on the top and bottom of your penny battery. If you want your LED to stay lit without having to hold it, wrap the entire assembly together with electrical tape. The LED will grow fainter as the matboards dry out, but it should stay lit for 24 hours! To recharge, just re-soak the matboards and reassemble.


What’s Going On?

Batteries are devices that convert chemical energy into electrical energy. When two different metals are connected by an electrolyte, a chemical reaction occurs at each metal surface, called electrodes, that either releases or uses electrons. When these electrodes are connected by a wire, electrons will move from one surface to the other, creating an electric current.

Pennies that were made after 1982 have zinc cores that are plated with copper. By sanding off one face of a penny, you create a zinc electrode that can pair with the copper electrode on the face of the next penny. The matboard soaked in salty vinegar water serves as the electrolyte between the two terminals.

Each zinc-matboard-copper stack represents one individual cell. By stacking additional matboards and sanded pennies, you’ve created a battery, which is a series of electrochemical cells. This is also called a voltaic pile, which is named after Alessandro Volta, who created the first battery in 1800 by alternating zinc and copper electrodes with sulfuric acid between them. In Volta’s battery and your penny battery, an oxidation reaction occurs at the zinc electrode that releases electrons and a reduction reaction occurs at the copper electrode that uses them.

With a voltmeter, you can see that each cell can generate over 0.6 volts. The penny battery you created for this Snack has four cells. A stack of three cells should generate enough voltage to light a red LED, which usually require around 1.7 volts.


Going Further

For an added challenge, try making a battery powerful enough to light a blue LED. 

Before 1982, pennies were made of 95% copper, but the rising costs of copper led the United States Mint to change the composition of the penny. The metal content in a pre-1982 penny is actually worth more than its one-cent face value. Consequently, in December, 2006, the United States Mint implemented regulations that prohibit the melting or treatment of all one-cent coins.

Legal disclaimer: The Exploratorium does not take responsibility for any damaged coinage, and certainly don’t try to sell your completed battery for more than 5¢!



Related Snacks

Science activity that demonstrates charge in a battery
Hand Battery

Use your skin and different metals to create a battery.

Science activity that demonstrates the chemistry of batteries
Aluminum-Air Battery

Construct a simple battery that can power a light.

Science activity that demonstrates conductivity of solutions
Conductivity Meter

Make a conductivity meter and let your electrolytes shine.



Creative Commons License



This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Attribution: Exploratorium Teacher Institute

  • Education
    • Teacher Institute
    • Tools for Teaching and Learning
      • Science Snacks
        • Browse by Subject
        • Special Collections
        • Science Snacks A-Z
        • NGSS Planning Tools
        • Frequently Asked Questions



Connect with us!



  •   Sign up for our educator newsletter

  •   Follow #ExploEDU

  •   Teacher Institute YouTube

  •   Teacher Institute Facebook

  •  teacherinstitute @exploratorium.edu

Exploratorium
Visit
Join
Give

Pier 15
(Embarcadero at Green Street)
San Francisco, CA 94111
415.528.4444

Contact Us

  • Plan Your Visit
  • Calendar
  • Buy Tickets
  • Getting Here
  • Store
  • Event Rentals
  • About Us
  • Become a Member
  • Donate
  • Jobs
  • Volunteer
  • Press Office
  • Land Acknowledgment

Get at-home activities and learning tools delivered straight to your inbox

The Exploratorium is a 501(c)(3) nonprofit organization. Our tax ID #: 94-1696494
© 2023 Exploratorium | Terms of Service | Privacy Policy | Your California Privacy Rights |