cool battery experiments

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STEAM Project: Tiny Dancers (A Homopolar Motor)

March 10, 2015 by Ana Dziengel 71 Comments

Today we are getting a bit artsy with our science! Does the idea of making a wire sculpture that “dances” entice you……? Tiny Dancers is the third project in our collaborative series STEAM POWER: Empowering kids to explore the world through creative projects. Today’s topic is HARNESS!

This post contains affiliate links to products I love and recommend to my readers.

SAFETY NOTE:

Neodymium magnets are extremely strong and MUST BE KEPT OUT OF REACH OF SMALL CHILDREN! Do not give them to any child who might put them in their mouth, they are dangerous if swallowed and must be surgically removed! This is a project for older children who can understand the precautions and I recommend ADULT SUPERVISION! For more about neodymium magnets safety and precautions go here Additionally neodymium magnets can interfere with electronic devices so please keep them away from phones!

Also please note that these motors do heat up. See our TIPS section for safety precautions.

Tiny Dancers (A Homopolar Motor)

Note: Before we get started I want you to know that despite this looking very easy there is a fair amount of TWEAK TIME you will need to invest to make this project work! I recommend starting with a BASIC HOMOPOLAR MTOR to get the hang of how the motor actually works, then trying your hand at making a tiny dancer. Each dancer will need to be tweaked to get them to dance properly on a battery. Don’t be discouraged if at first it doesn’t work, keep tweaking and see our tips sections for some troubleshooting solutions.

download our template here

Copper Wire- THIS is the gauge we used
1/2″ x 1/8″ Neodymium Disc Magnets
3 in 1 Combination Tool or pliers/wire cutters
Crepe Paper (optional for skirt)
Hot Glue (optional)

Instructions

Steps One Cut a long piece of wire off your spool, I started with about a 10” long piece. Lay it on the template of your choice and bend as shown using 3-in 1 tool or pliers. No need to be perfect HOWEVER try and keep your form as symmetrical as possible.
Step Two To create the base section of wire that wraps the magnets, I recommend bending the end of the wire around the battery. Remove the battery and gently widen the circular wire form with your fingers.
Step Three Place three neodymium magnets on the negative side of your battery.
Step Four Place the motor on top of the battery so that it touches the positive pole. The round section at the bottom of the motor must be low enough to encircle the magnets!
Step Five Let it go. If properly constructed it should start to spin. If it doesn’t see our tips below.
Step Six (optional) to make a skirt for your dancer cut a small circle of crepe then cut a slit in the center of the circle. Slide it up onto the dancer and secure in place with a dab of hot glue.
MONITOR THESE FOR HEAT! Some of the motors that got going really fast heated up quite quickly. If you notice a battery getting usually warm stop the project, let it cool down and remove the magnets. I recommend against reusing a battery that got overheated. Instead replace it with a fresh battery. One educator warned me about a defective battery that peeled open during this experiment. Please monitor the motors closely as they spin.
Start with your basic homopolar motor. It’s easy to bend and shape and you should have success with it. The dancers require more time to fine tune.
Keep the forms as symmetrical as possible! Since they spin on an axis if the are not symmetrical and/or balanced they will spin off the battery! This happened to us all.the.time. If they do spin off try and bend the form slightly to get them balanced on the battery.
To make the head of the dancer, bend your wire around a pencil.
Thin wire does not work! We tried this with very thin copper wire at first and it did not work. Stick to heavier gauges. Here is the gauge we used.
The templates are meant as GUIDES ONLY! The motors will need to be fine tuned by hand by you!
Remove the magnets immediately after running your motor. They will drain your motor if kept attached.
When the electrical circuit is completed you will hear a very low buzz.

Troubleshooting

If the motor does not work try turning your magnets upside down and reversing the polarity . I found this did the trick most of the time.
The batteries burn out quickly! If turning the magnets upside down doesn’t work, try replacing your battery with a new one.
Make sure that the bottom section of wire encircles the magnets. If it doesn’t your motor will not work.
Be sure your wire is free to move around the battery and magnets. If it’s too close to the battery or magnet it will get stuck and be motionless.
I read that you can use a nail to put a small indentation in the top of your battery to help keep the motor in place. I highly recommend AGAINST doing this . I tried it! One small and light dent worked and the next dent smashed a hole in the battery causing battery acid to spin on my counter! Eek! I decided off balance motors were better than battery acid splashes.

What’s happening?

I’m going to keep this as simple as possible because let’s face it, electromagnetism is hard to explain! Basically homopolar motors demonstrate something called a Lorentz Force . This is a force that is generated when electricity moves through a magnetic field. Our copper wire is conducting electricity from one end of the battery to the other. As it moves through the magnets on the negative side of the battery, it creates a force which causes the wire to spin .

You can read more about the Lorentz force and homopolar motors here and here .

Hendrik Lorentz. Hendrik Lorentz was a Nobel Prize winning Dutch physicist who inspired Albert Einstein! The Lorentz Force is named after him though he was not the first to discover its existence. In his early years Lorentz was primarily interested in studying electromagnetism and light. Albert Einstein used Lorentz’s paper “ On the Electrodynamics of Moving Bodies “ as the basis of his own work and the theory of special relativity. It’s super complex stuff but suffice it to say Lorentz ‘s studies of electromagnetism laid the groundwork for some of the most important scientific discoveries of the last century.

Ready for more projects that harness energy?

My fellow bloggers have done a wide variety of projects you have to check out!

Simple Circuit – What Do We Do All Day

Rubber Band Car – All for the Boys

Lego Inspired Electric Dough – Lemon Lime Adventures

Design Thinking – Meri Cherry

Mason Jar Solar Night Lights – Tinkerlab

Electromagnetic Train – Frugal Fun For Boys

10 Ways to Play & Learn with Springs – Left Brain Craft Brain

If you are looking to incorporate more STEAM ideas into your family’s creative day check out our STEAM Kids Book

Fill your child’s life with more art, design, science, and engineering.

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March 10, 2015 at 7:06 am

Well…. that is pure awesomeness!

Ana Dziengel says

March 10, 2015 at 9:32 am

Thanks Mama!

Jillian Burt says

May 15, 2016 at 2:46 am

Rachel says

December 12, 2016 at 6:57 pm

ok, i am in 5th grade and I’m doing the tiny dancers for my science project. THIS IS SO COOL!

December 14, 2016 at 6:44 am

March 10, 2015 at 8:51 am

Love the combo of adorable dancers and battery power! My daughter just gave the highest compliment: “I want to do that! Now!”

Meri cherry says

March 10, 2015 at 10:02 am

You just blew me away.

March 11, 2015 at 7:01 am

These are adorable, Ana. Just adorable!

Rachelle | TinkerLab says

March 11, 2015 at 6:07 pm

I love the simplicity of this (and yet, it seems quite complicated). Brilliant, Ana.

March 25, 2015 at 6:02 am

Thank you so much Rachelle!

Cait Fitz @ My Little Poppies says

March 19, 2015 at 12:25 pm

This is AMAZING. I cannot wait to try this with my STEM-obsessed little dancers. Thank you so much for sharing. The video was incredible, too, by the way! Nicely done!!

March 25, 2015 at 5:58 am

Thank you so much Cait!

Mariana says

March 20, 2015 at 5:22 pm

What a great idea!

March 25, 2015 at 5:57 am

Thanks Mariana!

Leslie says

March 23, 2015 at 11:39 am

These are so cool! 🙂 Love how they look like they’re dancing!

March 25, 2015 at 5:55 am

Thanks Leslie!

March 25, 2015 at 6:04 am

I see you have a link for the magnets, but do you have any ideas of where I might be able to find them locally? (Or type of store that might carry them?) Thanks for the great idea! My kids can’t wait to do this activity!

March 25, 2015 at 6:13 am

Possibly Radio Shack or an electronics store but they usually stock only ceramic magents which are not strong enough. Call ahead and see!

Sallie says

April 26, 2016 at 12:53 pm

Do you think ferrite magnets might work? I am having a hard time paying $20 for neodymium magnets!

April 30, 2016 at 4:07 am

Hi Sallie, I’m not sure but magus is they will not work. They just don’t have the power of neodymium.

Meghan @ PlaygroundParkbench says

May 31, 2015 at 7:45 am

Planning a ballerina-themed birthday for my oldest this summer… these will make the cutest centerpieces. Do you think they would work with a bigger battery too?

June 5, 2015 at 6:00 am

They are pretty finicky so I’d stick with the small battery. Plus these babies get got after spinning awhile so take precautions if experimenting with a larger battery 🙂

Jennifer says

June 6, 2015 at 8:37 pm

What guage wire did you use?

June 23, 2015 at 4:45 am

16 Gauge. Here’s the product we used: http://amzn.to/1BJcthJ

November 17, 2015 at 12:06 pm

Sorry to keep pestering–that link is broken too! I’m not sure where to buy the battery?

November 19, 2015 at 4:17 am

No prob! Here is a link 🙂 http://amzn.to/1S6bawG

Tracy Hart says

June 10, 2015 at 9:18 pm

The link to buy the magnets is broken. Could you tell me which size I should order off Amazon.

June 23, 2015 at 4:40 am

Thanks for letting me know! Here is the link : http://amzn.to/1CqrBeF

Shannon says

June 29, 2015 at 12:05 pm

This is not working for us. I tried all of your troubleshooting tips but no luck. Any ideas?

July 18, 2015 at 6:07 am

Sorry I’m just seeing this Shannon! Did you get it to work? I’m happy to help you troubleshoot if you still need it. Email me at [email protected] .

Shanna Taylor says

July 2, 2015 at 9:35 am

What size are the magnets that you used? I am figuring out that they are not easy to find. Thanks!

July 18, 2015 at 6:05 am

1/2″ diameter x 1/8″ thick. They are best ordered online 🙂

Bridget says

July 7, 2015 at 5:54 pm

How long approximately would an AA battery last if they dance non-stop?

July 18, 2015 at 6:00 am

I’m not sure. Ours burnt out after a day or two of use but we didn’t have them running non stop. I probably wouldn’t leave them running indefinitely as the battery gets hot. They should be run with supervision.

Elizabeth says

July 17, 2015 at 6:59 am

Can you put another link to the magnets? The link is no longer working. Thank you

July 18, 2015 at 5:59 am

Thanks for letting me know! The link has been updated 🙂

Kenan okan says

September 16, 2015 at 9:01 pm

deneyi yapıyordum ama sizinki daha güzel. Teşekkür.

October 19, 2015 at 6:56 pm

Can you use Bare Copper 16 Gauge Artistic wire?

November 9, 2015 at 9:17 am

I believe that should work 🙂

October 20, 2015 at 5:02 am

Awesome article!! The magnets are available at all Michael’s craft stores, and I believe A.C. Moore also carries them. Cool!!

November 9, 2015 at 9:16 am

Good to know!Thanks!

November 18, 2015 at 6:11 pm

This project was done at my school and me and my class mates loved it

November 19, 2015 at 4:04 am

I love hearing this Lena!!! It makes my day!

Catherine Stephenson says

November 22, 2015 at 1:09 pm

I absolutely love this science project idea. The fact that it is tailored to little girls I think makes it more attractive for them. These type of projects can often be more of boy interest. Keep it up!

November 24, 2015 at 7:34 am

Thank you so much for the encouraging words!

Kimberly says

January 13, 2016 at 6:15 am

January 16, 2016 at 5:16 pm

Do you have to use that size disc battery or can you use a little bigger one? The next size up is all I can find on amazon. The link posted for the magnets, is not secure for credit card. My pop up security feature came up when I tried to order there. 🙂

February 23, 2016 at 7:46 am

what age group do you think this is for? my daughter in middle school and is doing this for her school.

Levent Suberk says

February 29, 2016 at 4:00 pm

Thanks for this article. You wrote that “If the motor does not work try turning your magnets upside down and reversing the polarity.” But this only reverse the motion of wire, it does not affect working.

project centre says

March 10, 2016 at 2:09 am

Awesome job with batteries. That looks great. Thanks for your idea

March 18, 2016 at 2:33 pm

Thank you for this! Is there a way this project can be done for a class of students at a lower cost? IE: Would smaller batteries/magnets/wire have the same effect?

Hallo Bloggi says

April 4, 2016 at 1:55 am

Awwwwww!!!! Great idea! Thank you. Bloggi

April 8, 2016 at 4:59 am

Veronica Marino says

April 19, 2016 at 3:00 am

We had a big problem doing this activity. I used supplies [magnets, wire] from the sources you cited and duracell batteries. I first had the students shape the wire and then gave out the batteries, waiting to put the magnets in place only at the very end. After about 2-3 minutes more than one pair of students noticed the batteries getting warm, one very much so–and that battery actually peeled open and we had to shut down the activity! I think it was a defect with the battery, but I thought I should highlight this for other users/educators so that they know that the batteries need extreme caution and that in general this is an experiment with a high degree of caution

April 19, 2016 at 2:23 pm

Hi Veronica, Thank you for sharing your experience. I do have a warning in the post that these heat up and I appreciate you bringing it up again in your comment. I did this project many times without an issue of a battery peeling open though some batteries did get warm over time. I will add an additional note about your concern. Thank you, Ana

Jacquelyn says

April 25, 2016 at 7:06 pm

Put a small nut on top of the battery and the dancer will stay centered. I lost my patience with trying to tweak it!

April 30, 2016 at 4:04 am

Thanks for the tip!

Ana Rodz says

April 29, 2016 at 8:24 pm

We are doing this project for my son’s science fair. The hardest thing was finding the magnets we found a good deal on ebay. And instead of tiny dancers we are doing rockets and airplanes. Let’s see how bit goes. Thanks for the step by step video

August 16, 2016 at 4:29 am

Rockets and airplanes sounds great! I hope it was a success!

May 27, 2016 at 2:51 am

Amazing post Ana!!! I appreciate your talent. Here you described step by step procedure. I really love the dancers and the battery power. Keep up…

May 30, 2016 at 7:11 am

At first, I was like this is the perfect project for STEM , I’m going to do this… Then when it said all the negative and dangerous things about the battery I’m still confused should I do it or not?

August 15, 2016 at 8:34 am

It’s great for older kids. Anyone that tries it should be aware of the potential safety concerns which is why I have added the Safety Notes.

July 3, 2016 at 5:15 pm

Thank you for sharing, we have not yet success in getting it work….

July 8, 2016 at 8:00 am

I’m sorry to hear that Koko. Have you checked out our troubleshooting section?

Rafaella says

August 20, 2016 at 9:08 am

I need photos of the steps, but i don´t know in were can i found it!!!

Anyway thanks for the experiment!!

August 21, 2016 at 12:42 pm

Hi Rafaella, What steps are you looking for images for? Ana

Diana @ Toys for kids says

October 4, 2016 at 2:18 am

What a great idea! This is awesome! Thanks for sharing this creativity. Amazing post!

October 31, 2016 at 12:41 pm

Yay! Glad you liked it!

Louise says

November 30, 2016 at 8:02 pm

I love your ideas here and I wanted to use one of your activities for a school assignment, how would I be able to reference you in APA format?

December 9, 2016 at 5:38 am

What is APA format?

Share This Activity

Batteries come in all shapes, sizes and compositions. And while they often go unnoticed, these small, handy power packs provide a steady supply of electrical energy that powers some of life’s most essential items.

Batteries come in all shapes, sizes and compositions.

And while they often go unnoticed, these small, handy power packs provide a steady supply of electrical energy that powers some of life’s most essential items.

The different types of batteries include:

Household batteries (rechargeable and non-rechargeable). These are the most common types of batteries that power things like cell phones, toys and hearing aids.
Industrial batteries. These batteries exist to power heavy-duty systems like machinery, railroad and telecommunications systems.
Vehicle batteries. These are large, yet fairly easy to use. And they power our cars, motorcycles, boats and other motorized vehicles.

What’s the science behind batteries?

In a nutshell, a battery slowly converts chemicals packed inside it into electrical energy, or electricity. That energy is typically released over a period of days, weeks, months or even years.

The electricity is produced through an oxidation/reduction reaction which occurs when electrons are transferred from one substance to another.

5 Battery-Powered Science Experiments to Try In After School

In honor of National Battery Day, we’ve rounded up a few of our favorite battery-powered experiments for students to try after school.

*These activities require adult supervision. While most are designed for older students, younger students may participate and will enjoy watching the experiments.

Make a Lemon Battery

Create a battery out of lemons that produces enough energy to power a digital clock!

4 galvanized nails
4 pieces of copper
5 alligator clip wires
A small digital clock to power up

Visit Chrome Battery to see the full experiment.

Electrolysis of Water

Use the energy from a 9V battery to separate liquid molecules (hydrogen and oxygen) to create even more energy. As a result, the energy produced will literally split the water! In this experiment, students will test to see which water solution is the best conductor of electricity.

Distilled water
2 silver-colored thumb tacks
Small, clear plastic container
2 test tubes
Baking soda
Dishwashing detergent

Visit Education.com to see the full experiment.

Which Battery Lasts the Longest?

This experiment explores the difference between alkaline and non-alkaline batteries. Students will also determine which type of battery lasts longer: brand-name batteries or generic brands.

Several different brands of AA batteries. Try to purchase batteries that all have roughly the same expiration date (at least within the same year), and note the price you paid per battery. Here are some suggestions:
Brand-name batteries (Rayovac, Energizer, Duracell, Eveready and Panasonic)
Generic brands (CVS, Walgreens, Rite Aid and Kirkland/Costco)
Several identical flashlights that take two AA batteries (get one flashlight for each type of battery you plan to test)
Clock or watch
Masking tape (for labels)

Build an Electric Motor

Harness the power of one AA battery to build an electric motor that spins!

One AA Battery
Copper Wire (18 gauge should work)
A neodymium (rare earth) magnet
Wire cutters
Needle-nosed pliers

For the optical illusion version:

Colored pencils

Visit Frugal Fun for Boys and Girls to see the full experiment.

Dirt Battery

This experiment doesn’t involve an actual battery. But it uses ordinary items and materials, like dirt, to build a makeshift battery that can power a little LED light!

Ice cube tray
Galvanized steel screws
Copper wire
LED pin Lights

Visit Teach Beside Me to see the full experiment.

Batteries are small power packs that make it possible for cell phones, medical devices and other essential technologies to exist. Use these battery-powered science experiments to help students explore the magic of batteries after school.

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