science experiment potato

Advertisement

Potato Battery Experiment: Powering a Light Bulb With a Potato

• Share Content on Facebook
• Share Content on LinkedIn
• Share Content on Flipboard
• Share Content on Reddit
• Share Content via Email

Did you know you could power a light bulb with a potato? The chemical reactions that take place between two dissimilar metals and the juices in the potato create a small amount of voltage that can power a very small electrical device [source: MadSci].

Follow the instructions below to make a potato battery .

How to Make a Potato Battery

The science behind potato battery experiments, using potato batteries to power other devices.

• One potato (ideally large)
• Two pennies
• Two galvanized nails (zinc-plated nails)
• Three pieces of copper wire
• A very small light bulb or LED light

What You Need to Do:

• Cut the potato in half, then cut a small slit into each half, large enough to slide a penny inside.
• Wrap some copper wire around each penny a few times. Use a different piece of wire for each penny.
• Stick the pennies in the slits you cut into the potato halves.
• Wrap some of the third copper wire around one of the zinc-plated nails and stick the nail into one of the potato halves.
• Take the wire connected to the penny in the half of potato with the nail and wrap some of it around the second nail. Stick that second nail into the other potato half.
• When you connect the two loose ends of the copper wires to the light bulb or LED, it will complete the electrical circuit and light up.

Be careful when handling the wires, because there is a small electric charge running through the wires. Hydrogen gas may also be a byproduct of the chemical reactions in the potato, so don't perform the experiment near open flames or strong sources of heat [source: MadSci].

Batteries store energy for later use, but where does the energy come from? All batteries rely on a chemical reaction between two metals.

In a potato battery, the reaction — between the zinc electrodes in the galvanized nails, the copper in the penny, and the acids in the potato — produces chemical energy.

The potato doesn't produce electricity, but it does allow the electron current to flow from the copper end to the zinc end of the battery.

You can try using multiple potatoes to power other battery-equipped devices, like a clock.

In the battery compartment, connect the potato with a copper coin inside to the positive terminal (marked with a "+") and a potato with a galvanized nail inside to the negative terminal (marked with a "-"). Learn more about how to make a potato clock.

With any potato battery experiment, if your battery doesn't power your device on the first try, you can try increasing the number of potatoes. You can also use other fruits and vegetables to make batteries — lemon, which is highly acidic, is a popular choice.

"Food Batteries." MadSci Network. Mar. 14, 1998. (Sep. 20, 2023). https://www.madsci.org/experiments/archive/889917606.Ch.html

Potato Battery FAQ

How does a potato battery work, can a potato light up a light bulb, why does my potato battery not work, how many amps of energy can a potato battery produce, does using a boiled potato result in more power.

Please copy/paste the following text to properly cite this HowStuffWorks.com article:

Potato Power!

[vc_row][vc_column][vc_column_text]

Explore the science behind the popular potato battery Science Fair project! Want to know how potato batteries work? It might simply look like a couple of potatoes with clips, wires and pennies sticking out of them in all directions. But when you connect the wires and pennies – WOW!  It creates energy!   

 [dt_divider style=”thin” /], potato battery demonstration, what is a potato battery.

A battery is something that causes chemical energy to be converted into electricity. Batteries have a positive side (terminal) and the negative side (terminal). The negative side is the source of the electrons that gives the energy to a wire that is connected to an electronic device. Batteries power electronic devices when connected with a conductive material, such as wires.

The potato battery is a type of electrochemical battery, or cell. Certain metals (zinc in the demonstration below) experience a chemical reaction with the acids inside of the potato. This chemical reaction creates the electrical energy that can power a small device like an LED light or clock. Incredible, huh?

There are a few different ways to create batteries. Different batteries can be made from different electrolytes (acidic fruits, vegetables and liquids) and different electrodes (metals).

An electrochemical battery has these parts:

• Acidic Electrolyte
• Zinc Electrodes
• Copper Electrodes

Gather these supplies:

• 3 Fresh clean potatoes – acidic electrolyte
• 3 Galvanized nails (or screws) – they have a zinc coating and will be used as your zinc electrodes
• 3 US Pennies (or copper wire with exposed copper end) – Pennies newer than 1982 are thinly copper-plated, while older ones have more copper. The pennies will be used as your copper electrodes
• 5 Dual alligator clip connectors (10 actual clips total) – you can find these at most hardware or electronic stores
• 1 LED clock that has a battery compartment

Now make a potato battery!

• With the close supervision of an adult, insert one nail about 1 inch into the potato end. Make sure not to poke all the way thru the potato. Use a pen to write a minus sign “-” next to the nail.
• Push one penny into the opposite end of the potato. Make sure most of the penny is still sticking out. Use a pen to write a plus sign “+” next to the penny.
• Repeat steps 1 and 2 with the other two potatoes.
• Connect the potatoes so that the penny on potato 1 is attached to the nail in potato 2.
• Connect the penny from potato 2 with the nail from potato 3.
• Connect the nail from potato 1 to the penny from potato 3.
• Open the battery compartment to your clock. Look for the “+” and “-” signs on either side of the battery compartment.
• Connect the nail from potato 1 to the negative terminal inside the battery compartment of the clock and the penny from potato three into the positive terminal inside the battery compartment of the clock.
• Once everything is connected, observe what happens!

Explore the science behind the potato battery

Now you’ve had fun building your potato battery and maybe even surprised a few people when that clock turned on using a potato . Now, let’s look at the how you can find out more about the real science of how it works. Some of the science might be tough to understand if you aren’t in middle school yet, but you can still give it a try.

The science behind a topic is called its scientific principles or concepts. Let’s learn a little more about the science of the potato battery by doing some background research. To do your background research, you can ask an expert, look in books or search the internet.

Below are some scientific principles and concepts of potato battery experiments that would be helpful for you to understand in order to plan your project. When searching the internet, include “kids” in your search to get age-appropriate information. For example, “kids potato battery project”.

• Acid (Late Elementary)
• Electrons (Late Elementary)
• Electrolyte (Middle)
• Electrical currents (Middle)
• Electrically conductive (Middle)
• Electrodes (Middle)
• Circuit (Middle)
• Voltage (High)
• Current (High)
• Oxidation-reduction (High)

[dt_divider style=”thin” /]

Now, think like a scientist.

Scientists make observations, ask a lot of questions, then try to find ways to answer those questions. They use their understanding of scientific concepts to explore their questions. Here are a few questions for you to try to ponder now that you have learned some scientific concepts:

• Think about all of the different toys, gadgets and tools that use batteries. What can you learn about different battery types?
• What other fruits, vegetables or liquids do you think you could try experimenting with instead of a potato? Why?
• Will your potato battery power your small electronic device if you only use one connecting wire? Why or why not?
• What other types of metals could you experiment with as electrodes?
• How do you think changing the environment would cause a change to your observations about the potato battery?

Inquiry Project

If your science fair allows inquiry projects (or demonstrations), then try to answer “why” or “how” questions as part of your project. In your own words, describe the scientific concepts that you learned about and some of the things you observed or discovered. The purpose of an inquiry is to demonstrate what you learned, observed and discovered. Demonstrations are not the same as experiments but can involve you having fun collecting data.

Experimental Project

When you do an experiment, you choose one thing to change and try to understand the results of that change. This is called Cause and Effect. If your science fair only allows experimental projects that follow “The” Scientific Method, then follow these steps:

•  After learning the science behind the potato battery, decide on just one thing that you will change during your experiment and what you will measure. For example, maybe you make a lemon battery instead of a potato battery.
• Write a detailed experimental question that makes it clear what you will change.
• State your prediction as a result of a change that you make.
• Plan how you will set up your experiment, including necessary supplies.
• Determine the potential health and safety risks of doing your experiment.
• Write down a detailed procedure that you can use when doing your experiment.
• Collect and record your data and observations.
• Display your data in a table and graph.
• Look for trends in your data graph.
• Try to explain why your data or observations turned out the way they did.
• Share what you learned with others.
• Create a project board display – refer to Project Display Tips

Want a little more help taking charge of your project? Let Mo and Pepper lead you step-by-step through an experimental project in Make Science Fair Fun ®![/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

© 2022 STEM World Publishing, Public Benefit Corporation, with permission.

[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_cta h2=”Want to promote authentic STEM projects at your school?” h2_font_container=”tag:h2|font_size:48px|text_align:left|color:%23a11d21|line_height:60px” h4=”Help us connect with your school district to donate our impactful programs to you and your school community!” h4_font_container=”tag:h2|font_size:24px|text_align:left|line_height:30px” add_button=”bottom” btn_title=”Learn More” btn_color=”turquoise” btn_size=”lg” use_custom_fonts_h2=”true” use_custom_fonts_h4=”true” h4_link=”|||” btn_link=”url:https%3A%2F%2Fstemgeneration.org%2Fprograms%2F|title:Parents%20-%20Inspire!|target:_blank”][/vc_cta][/vc_column][/vc_row]

Similar Posts

Common Science Fair Budget Items

Creating a budget for your Science & Engineering Fair is not necessary. But if you have a source for funding, then you can add some perks for increasing student and family engagement. You might ask your principal, parent-teacher organization/association, or student council if they have a budget for your fair.

Birth of STEM Generation

In 2015, a teacher reached out to me to share a story a couple of weeks after I provided her with full support at a Title 1 school to organize their Science & Engineering Fair. She explained how one of her most at-risk students had come to her the day after the fair and had…

6 Steps of Innovative Science & Engineering Fair Projects

Looking at a Science & Engineering Fair project in small steps can help make such a big project seem a lot more manageable. The Make Science Fair Fun® experience involves these 6 easy-to-follow steps. 

Create Effective Science Fair Signups

If you want students to participate in your school’s Science & Engineering Fair and for adults to support you during your fair, then you will need signups. Gauge whether online or paper signups will be most effective at your school. Consider that not all families have access to or are receptive to the use of internet tools. We’ve seen schools use online only, paper only, or the combination of the two.

Top 3 Parent Tips for Inspiring your Child to Innovate

Effectively mentoring your child on their Science & Engineering Fair project can be more challenging than actually doing the project itself. Have the patience to help your child develop the skills to work through challenging times, while empowering them to stay in the driver’s seat.

Science Fair Position Statement

We at Science Fair Fun recognize the potential for Science & Engineering Fairs to be ideal incubators for inspiring and empowering our next generation of innovators when those fairs align with the following principles:

Science Project Ideas

Potato Clock or Potato Battery

The potato clock science project teaches students the principle behind the working of a battery. The experiment is an ideal one to be performed at science fairs to invoke curiosity in kids on the science behind current and electricity. It is good to have some background information on the traveling of current from the positive to the negative terminal of a battery and that of electrons in the opposite direction before embarking on the investigation. Then, in case the potato battery clock does not work, they know how to troubleshoot.

How to Make a Potato Battery

On making the connections as explained below, 2 potatoes power a LED clock that has its actual battery removed.

• 2 galvanized nails
• 2 small pieces of heavy copper wire
• 3 alligator clips
• A low voltage LED clock that uses a 1-2 volt button type battery

Instructions

• Remove the battery from the clock making a note of which end (positive or negative) of the battery went to which terminal point in the battery compartment of the clock.
• Number the potatoes as 1 and 2 with the marker.
• Insert a nail in each potato.
• Insert a copper wire into each potato a far away from the nail as possible.
• Use an alligator clip to connect the copper wire in potato 1 to the positive terminal in the battery compartment of the clock.
• Connect the nail in potato 2 to the negative terminal in the battery section of the clock using the alligator clip.
• Connect the nail in potato 1 to the copper wire in potato 2 with the 3 rd alligator clip and watch the clock turn on.

Note that the battery lasts for only a short span of time. Drawing the circuit diagram prior to conducting the experiment minimizes the chances of errors.

Potato Powered Clock Video

Here is a video to help you carry out the building procedure.

How Does a Potato Clock Work

Being an electrochemical cell, a potato battery transforms chemical energy into electrical energy. A transfer of electrons takes place between the zinc coating of the galvanized nails and the copper wire inserted in the potatoes with the help of the alligator clips that complete the circuit resulting in a chemical reaction. Here the potato provides a favorable medium for the transfer of the electrons. That charges the clock.

• Research has shown an easily available and a green source of energy, potato clocks, could power cell phones and other small electronic appliances in remote, underdeveloped places having no access to a power grid.
• Boiling the potatoes further increases their electrical conductivity.

You Can Try

• Test if it can power a digital alarm clock, light bulb and flashlight. You might have to play around with the number of potato pairs connected in series to achieve the objective.
• Substitute the copper wires with copper pennies. Does it work?
• Can you measure the voltage supplied by the potato battery? Consider using a voltmeter or a multimeter for this.

A lemon battery utilizes a similar theory. Hence, after doing the activity with potatoes, you can repeat with lemons, bananas and apples and check the voltage and/or brightness supplied by them. A data chart for the observations and a graph with the voltage as the dependent variable and the fruits and vegetable as the independent one could make the comparative study easier. You may also prepare a display board to demonstrate the DIY tutorial in the lab.

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Potato Light Bulb Experiment

Please enable JavaScript

(Physics for ages 8+)

If you’re looking for an exciting and boredom-busting activity, this just might be the one for you! Did you know you can use potatoes to light up a light bulb ? It seems crazy, but there is electrical energy all around us and even in everyday things like the food we eat. The video above shows exactly how it’s done. Here’s what you’ll need:

Potatoes Copper wire or copper nails Iron-galvanized nails Electrical wire (with or without alligator clips) Light bulb Voltmeter (optional) Adult supervision (Adult supervision at all times please)

• Start by inserting a 3-inch piece of copper wire about half-way into each of your potatoes (use 2, 3, or more potatoes if you’d really like to ramp up the voltage and brightness of the light bulb).
• Next, insert an iron-galvanized nail half-way into each of your potatoes. For best results, try to insert the nails about an inch away from the copper wire pieces.
• If you are using thin electric wire without alligator clips, you will need to remove some of the plastic covering. Cut two 6-inch strips of wire per potato you are using (if you are using 2 potatoes you need 4 strips, 3 potatoes will need 6 strips, and so on). Have an adult help you remove about ½ inch of plastic covering from both ends of each of the wire strips.
• You will need to attach the wires to your nails to complete an electrical circuit. In doing this, it is important to note the copper wire is the positive terminal (like the positive end of a battery), and the iron nail is the negative terminal. If you are using wires with alligator clips, simply clip one end to the copper wire of potato 1, and the other end to the iron nail of potato 2. If you are starting with just one potato, clip one wire from the copper wire to the light bulb, and connect another wire to the iron nail and light bulb. If you are using wires without alligator clips, simply wrap the exposed ends of the wire around the tops of the iron nails and copper wire pieces.
• Complete your circuit by attaching a strip of wire from the positive terminal (copper wire) of one potato to the negative terminal (iron nail) of the next potato. When you are finished, the light bulb should be attached to the negative terminal of the first potato and to the positive terminal of the last potato in the series. Please see the video for clarification on building this circuit.
• If you have voltmeter, replace the light bulb with the test terminals of the voltmeter to test the voltage coursing through the potato circuit. Try starting with a small circuit of just one potato and work your way up to several potatoes, testing the voltage of each circuit. You can also try different types of potatoes to see which kind makes the most powerful circuit (for example: Russet versus Yukon gold).

A potato is made up of water, sugar, and acid. When certain metals, like the copper and galvanized iron, are inserted into it, they react and create a flow of electrically charged molecules to move from the negative terminal to the positive terminal.

This reaction also released hydrogen gas as the charged molecules move through the entire potato circuit. Each potato releases a certain voltage, so connecting them in a series increases the total voltage output, which in turn brightens the light bulb. What other kinds of food might work to create a “ food battery ?”

Science Experiments On The Osmosis Of A Potato

Osmosis, the process in which solvent molecules move from an area of lower solute concentration to an area of higher solute concentration, can easily be demonstrated with potato experiments. Potatoes are full of both water and starch, and will gain water when immersed in watery solutions. Conversely, they will lose water when in concentrated solutions, such as those containing a great deal of starch. You can use potatoes to set up osmosis experiments for students of all ages and levels.

Potatoes in Saltwater

Cut a potato in two, and immerse one of the halves in a very salty solution of water — one containing a quarter cup of salt in a cup of water. Immerse the other piece in tap water containing no added salt. Leave both in their respective solutions for half an hour, then remove the potato halves from their solutions and observe their differences. The one in the salty solution will have shrunk, indicating that water is diffusing from a less concentrated solution to a more concentrated solution. The one in the tap water solution, in contrast, will actually swell slightly, indicating that it is taking in water.

Salt, Sugar and Pure Water

This experiment helps students to differentiate between different degrees of concentration gradients. Make one salt water solution, one sugar water solution, and for the third solution, simply use tap water. Make three thin potato slices — 1/2 cm thick. Place each potato slice into each of the solutions, and leave the slices in the solutions for a half hour.

Observe that the slice placed in salt is very flexible, while the slice placed in sugar is flexible, but less so. Since potatoes already contain sugar, less water will diffuse out of the potato placed in sugar water. The slice placed in water will be rigid, since it will absorb water.

Potato Lengths in Saline Solutions

Give your students potato "cylinders" that are uniform in length and size: for instance, you could cut them to be 70 mm in length and 7 mm in diameter. Make solutions of saline in three different concentrations, 20 percent, 0.9 percent and 0.1 percent. Have the students measure the lengths and diameters of the potato cylinders before and after soaking them in the saline solutions for half an hour. Then, have them calculate the changes in the lengths and diameters of the cylinders, and plot the saline concentrations versus the changes.

Potato Cube Weights

Cut potatoes into four groups of small, uniform cubes measuring 1/2 cm by 1/2 cm. Make four different solutions of sucrose: 10 percent, 5 percent, 1 percent and 0.01 percent. Weigh each group, on a mass balance, before immersing it in the appropriate sucrose solution for half an hour. After immersion, weigh each group again and have your students calculate the changes in the potato masses. Ask them to comment on why a group gained mass, lost mass or retained the same mass.

• The Teachers Corner: Science Experiment–Osmosis

Cite This Article

Lobo, Tricia. "Science Experiments On The Osmosis Of A Potato" sciencing.com , https://www.sciencing.com/science-experiments-osmosis-potato-8360195/. 26 April 2018.

Lobo, Tricia. (2018, April 26). Science Experiments On The Osmosis Of A Potato. sciencing.com . Retrieved from https://www.sciencing.com/science-experiments-osmosis-potato-8360195/

Lobo, Tricia. Science Experiments On The Osmosis Of A Potato last modified August 30, 2022. https://www.sciencing.com/science-experiments-osmosis-potato-8360195/

Recommended