Electricity is a kind of energy that powers many things in our lives, like lights, computers, and phones. Even though you can't see electricity, you can feel its power when your hair stands up after rubbing a balloon on it, or when you see a lightning storm. That's why it's important to learn about electricity and how to use it safely!

This activity uses a common potato and two different metals to make a enough electricity to run a small digital clock. Try this activity then attempt to expand on it to create a neat science fair project.

Can a potato produce enough electricity to light an LED? A potato contains moisture and acid that allow a chemical reaction between two different metals. That reaction generates a small voltage.

You push two different metal strips (such as copper and zinc) into a potato. Then you connect a multimeter and read the voltage and current. Different metal combinations produce different amounts of power.

Wire two or more potatoes in series to add their voltages together. With the right combination, four potatoes can produce enough current to light two low-power LEDs.

POTATO POWER

Purpose:

In this activity, you will learn how to build a battery from potatoes.


Materials:

metal strips: copper, aluminum, zinc (galvanized steel)
potatoes (at least 4)
multimeter (volts, milliamps)
wire clips
steel wool (to clean the metal strips)

Procedure:

1) Select two different metal strips and one potato.
2) Carefully place the metal strips into the potato.
3) Voltage: Set the meter to "DC Volts" and make sure the probes are plugged into the correct jacks. Also make sure that the scale is correct. All multimeters are different, but there should be a low scale, something like 2V, or 6V.
4) Attach wires from the meter's probes to the metal strips.
5) What does the meter read? 
6) Current: Set the meter to "DC milliamps" and make sure the probes are plugged into the correct jacks. (Use the smallest setting on the multimeter.)
7) Attach wires from the meter's probes to the metal strips.
8) What does the meter read? (enter on the worksheet) (You may notice that the current decreases. As the current decreases, you are draining the battery. So take your measurement, then disconnect the wires.)

Additional experiments:
1) Different metals: Now that you know how to make a potato battery, and know what voltage and current are, you will try to make a better battery.
Some metals make better batteries than others. You will try to find the combination of metals that gives the most voltage and current.
What combination of metals made the most voltage and current together? 

2) Potatoes in Series
Make another potato battery.
Wire up the two potatoes in series.

3) Light the LEDs
Now you are qualified to be a battery engineer! Your job is to design a more complicated potato battery to light two LEDs.
Two LEDs need 1.6 volts and 1 milliamp to light brightly. The more current, the brighter the light. By putting potatoes in series and parallel, design a battery to do this:
Now test your battery with the LEDs. LEDs are special lights that have a positive side (red wire) and negative side (black wire). Make sure you attach the positive side of your battery to the red wire and the negative side to the black wire.

Notes
The best combination of metals should be copper and zinc.
The LEDs used here are special low current LEDs, rated for 1.8 V and 1 mA, but they will fire at about 1.6 V and .2 mA.
One LED should fire with 2 potatoes in series (this barely produces the needed 1.6 V), but you may need 3.
The 2 LED eyes are wired in parallel. Four potatoes should brightly light the eyes: two pairs in series, those pairs in parallel.
The zinc used here is really galvanized steel, meaning zinc coated steel. Zinc is dissolved from the strips in the battery, so the metal strips have a finite lifetime.

Potato Batteries: Metals, Voltage, and LEDs

How to make a potato battery

<h1><strong>1000 Science Fair Project Ideas by Subject</strong></h1><p>Looking for a science fair project idea? Each of our science fair project idea has complete instructions with video. Get ideas for your science projects, find extra resources for your class' scientific projects, or try a fun experiment at home! It doesn't matter what grade you're in, there's something for everyone!</p><p>You can find your perfect science fair project from the different science subjects below or from our <a href="https://www.all-science-fair-projects.com/category0.html#bottom">science fair project idea lists!</a></p>

<h2>Science Fair Project Idea Lists</h2><p>Looking for other ways to find good ideas for science fair projects? Check out these lists of science projects!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>Easy Science Fair Projects</h3><p><img src="/images2/flex/176_popular 2 (2).png" data-size="100" data-float="left" style="width:100px; float:left">Explore the exciting world of science with an easy science fair project that you can do at home using simple materials. Any one of these easy project ideas will teach you important scientific concepts and help you have fun while learning. An easy science fair project is a great way to introduce the wonders of science to kids and adults alike!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Changing the Color of Flowers</p></li><li><p>Baking Soda Volcano</p></li><li><p>Swimming Raisins</p></li><li><p>Egg in Vinegar</p></li><li><p>Color of Skittles Experiment</p></li><li><p>Jumping Rice Krispies</p></li><li><p>Mixing Colors of Light</p></li><li><p>Camouflage and Hide</p></li><li><p>Light and Dark on Seed Germination</p></li><li><p>Make a Parachute</p></li></ul><p>More science project details at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/12">Easy Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>The Top 10 Best Science Fair Projects</h3><p><img src="/images2/flex/177_popular 2 (3).png" data-size="100" data-float="left" style="width:100px; float:left">To find the best science fair project for you, we've picked the best science projects from 10 different science categories, all with very interesting topics. If you're looking for more science projects at another difficulty level or topic, you can explore science fair project ideas by grade level at the top of this page!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Jet Lag in Hamsters (circadian rhythm, Biology science fair project)</p></li><li><p>Egg with Vinegar (acid-base reaction, Chemistry science fair project)</p></li><li><p>Galileo's Inclined Plane Experiment (acceleration, Physics science fair project)</p></li><li><p>Plant's Favorite Color for Photosynthesis (Photosynthesis, Botany science fair project)</p></li><li><p>Color and Taste (color perception, Psychology science fair project)</p></li><li><p>Does Dog Saliva Kill Bacteria? 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With just a few simple things, you can be fascinated by science and have tons of fun with these popular science projects!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Explosive Elephant Toothpaste</p></li><li><p>Egg in Vinegar</p></li><li><p>Electrifying Lemon Battery</p></li><li><p>Making Oobleck: Liquid or Solid?</p></li><li><p>Egg Drop Project</p></li><li><p>Colors of Skittles Experiment</p></li><li><p>Cloud in a Bottle</p></li><li><p>Baking Soda Volcano</p></li><li><p>Egg in a Bottle</p></li><li><p>Plastic Milk</p></li></ul><p>Project details and more cool science projects at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/1/Popular_Science_Experiments_At_Home">Popular Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>One-Day Science Fair Project Ideas</h3><p><img src="/images2/flex/172_popular 2 (1).png" data-size="100" data-float="left" style="width:100px; float:left">Quick experiments can be a great option for a science fair project. In this list, we've highlighted one-day science fair project ideas for elementary school (easy), middle school (medium), or high school (hard). 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Science museums, natural history museums, space museums, and discovery museums are all great places to do that! You can discover all sorts of interesting things about science and find cool project ideas for science fairs.</p><p>There may be free admission days or free passes to a science museum near you! Check your credit card for offers, your local library for free museum passes, and nearby science museums for free entrance days.</p><p>So what are you waiting for? <a href="https://en.wikipedia.org/wiki/List_of_science_museums">Find a science museum near you</a> and prepare to be awed by all that you can learn there!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h4>Look around and observe</h4><p><img src="/images2/flex/117_5.png" data-size="100" data-float="left" style="width:100px; float:left">Do you know how scientists start their cool projects? They often look around and notice things that are interesting or make them curious. 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Check them out at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/12">Easy Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3 style="text-align: start"><strong>How do I start a science fair project?</strong></h3><p><img src="/images2/flex/199_science coach.png" data-size="100" data-float="left" style="width:100px; float:left">No matter if you're in high school, elementary or middle school, science fair projects are a fun and unique way to discover science by asking a question and doing a science project. We'll help you find a science fair project idea and guide you through the process of doing and presenting your science fair project with <a href="https://www.all-science-fair-projects.com/science_fair_projects_coach/science-project-coach.html">Science Fair Coach's Science Fair Project Guide</a>.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>What should I do after I have a science fair project idea?</h3><p><img src="/images2/flex/143_intro science fair.png" data-size="100" data-float="left" style="width:100px; float:left">If you have a science fair project idea, Science Fair Coach can help you turn it into a full science fair project! Starting at the <a href="https://www.all-science-fair-projects.com/pgpage/4">Introduction to Science Fairs</a>, check out the section on <strong>How to do a science fair project</strong> for a step-by-step guide!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p><img src="/images2/flex/203_compared to scientific method.png" data-size="100" data-float="left" style="width:100px; float:left">We'll guide you through every step of the <a href="https://www.all-science-fair-projects.com/pgpage/5">scientific method</a>, from designing and conducting your experiment to collecting and analyzing your findings.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p><img src="/images2/flex/202_engineering design process.png" data-size="100" data-float="left" style="width:100px; float:left">If you're working on an engineering project, you can head over to <a href="https://www.all-science-fair-projects.com/pgpage/9">The Guide to the Engineering Design Process</a>.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p> <img src="/images2/flex/150_science fair poster.png" data-size="100" data-float="left" style="width:100px; float:left">Finally, we'll help you showcase your results on a <a href="https://www.all-science-fair-projects.com/pgpage/7">science fair board</a> for others to learn from and enjoy.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3 style="text-align: start"><strong>How do I make a science fair board?</strong></h3><p style="text-align: start"><img src="/images2/flex/150_science fair poster.png" data-size="100" data-float="left" style="width:100px; float:left">Your science fair board is where you show off your science fair project for everyone to see and learn from. With <a href="https://www.all-science-fair-projects.com/science_fair_projects_coach/science-project-display-board-6a.html">Science Fair Coach's step-by-step guide</a>, you can make sure your science fair board stands out and impresses at the science fair!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>Where can I find a science fair competition?</h3><p><img src="/images2/flex/179_Intro Science Fair Projects 32.png" data-size="100" data-float="left" style="width:100px; float:left">Science fair competitions are an excellent opportunity to explore science. One of the of the premier science advocacy organizations, the Society for Science, is associated with more than 400 science fair competitions in almost every US state, as well as over 70 other countries, regions, and territories. You can find out if there's a <a href="https://findafair.societyforscience.org/">Society of Science affiliated science fair</a> near you!</p><p>The <a href="http://physics.usc.edu/~gould/ScienceFairs/">The www Virtual Library: Science Fairs website</a> also has a collection of science fairs from all over the world, as well as national, state, regional, local, and virtual competitions!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat">

Physics is the study of how the universe works. Physicists study everything from tiny particles that make up atoms to huge stars and galaxies. They help us understand how things move, how energy works, and even how time and space are connected!

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Potato Batteries: Metals, Voltage, and LEDs

Hypothesis

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