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Science Rocks!

Lemon Battery


your results

Sent in by:
Kendra of MO

This clock is citrus-powered!

Materials Needed

  • 2 lemons
  • 3 copper wires
  • 2 large paper clips
  • 2 pennies
  • a digital clock
  • scissors
  • knife



  1. Check with a grown-up before you begin.
  2. First, attach one of the paperclips to a wire.
  3. Then attach a penny to a second wire.
  4. Attach another penny to one end of the third wire, and a paperclip to the other end.

  1. Squeeze and roll two lemons to loosen the pulp inside.
  2. Make two small cuts in the skins of both lemons an inch or so apart.
  3. Put the paper clip that is attached to the wire and the penny into one of the cuts until you get to the juicy part of the lemon.
  4. Stick the penny into a hole in the other lemon.
  5. Put the other paper clip into the second hole of the lemon with the penny.
  6. Then put the last penny into the last open hole.

  1. Connect the free ends of the wires to the terminals of the digital clock.

  1. Watch how the lemons make enough electricity to turn the clock on. If you've hooked everything up and the clock isn't running, try switching the wires.

  1. Here's how this lemon battery works. There's a chemical reaction between the steel in the paper clip and the lemon juice. There's also a chemical reaction between the copper in the penny and the lemon juice. These two chemical reactions push electrons through the wires.
  2. Because the two metals are different, the electrons get pushed harder in one direction than the other. If the metals were the same, the push would be equal and no electrons would flow. The electrons flow in one direction around in a circle and then come back to the lemon battery. While they flow through the clock, they make it work. This flow is called electric current.
  3. This is hard to understand. So, if you need it explained to you again, be sure to talk to a parent or a teacher.

Now it's time to experiment. Do you think your lemon battery will still work if you change the lemons? Try cutting the lemons in half, or squeezing them and putting the wires in the lemon juice. Does your battery still work? Since lemon juice is an acid, think about how you can make batteries out of other acids, like orange juice or cola. Or see if your battery will work using a base, like soapy water. Choose one thing to change (that's the variable) and predict what you think will happen. Then test it and if you come up with some cool discoveries, send them to ZOOM.

Some of your Results

Kathrine of Salt Lake City, UT wrote:
First I tried it with lemons but it didn't work. Then I tried grapefruit it WORKED!

Alicia, age 10 of Detroit, MI wrote:
i did mine for a science project. practically everyone in my family helped. we couldnt get it to work.

Emma, age 10 of Goleta, CA wrote:
It worked. I tried it with lemons, limes. oranges, potatoes and tomatoes! It is so cool! No need o buy regular batteries, use organic ones!

Gabi, age 12 of Staten Island, NY wrote:
It didn't work for me. How did you guys get it to work? I even tried with 8 lemons and it still didn't work!

Dawn, age 12 of Barnwell, SC wrote:
I had to do mine for a science fair project and I used two lemons and two grapefruits. the reason why I used these things because I was trying to compare two unlike things and it worked.

Akhil, age 14 of Punjab, India wrote:
Lemon Battery really worked. It started mine clock. It also glow a small bulb. I love it. Mine teachers also liked it very much. It is fabulous.

Natalie, age 11 of Marysville, WA wrote:
Nothing happened and it didnt work! My partner and I made a lemon clock for a 6th grade science fair project and our teachers told us that it would work!! I dont understand why it didnt work!!!

Bishop, age 9 of Fort Gratiot, MI wrote:
When I tested my fruits, the apple was the best with 1. 00 V. The tomato and the lime came in second woth. 98 V each.

Robyn, age 10 of Hopewell Jct., NY wrote:
When I tried, the clock didn't work! I was so mad! But then, when I tried grapefruits, it worked! I also tried oranges, but those didn't work either.

Destiny, age 13 of San Jose, CA wrote:
it actually worked!!! WOW. it was really amazing

Terika, age 11 of Buffalo, NY wrote:
im doing a science fair project and im making a potato battery and a lemon battery and am going to power a lightbulb. To measure how strong it is, I will probobly see how bright it shines and make a scale or use one of those meter things. Ill write what happens soon

Ashvin, age 11 of Austin, TX wrote:
I used a lemon, a a grapefruit, a peach, and an orange. I used a galvanized zinc nail instead of a paperclip and measured the volts with a multimeter. lemon got the highest current and peach got the least. its awesome!!!

Chantel, age 12 of Willacoochee, GA wrote:
boy it was cool dude I didnt think it was goin to work but it did.

Daron, age 14 of Suitland, MD wrote:
the clock started to work

Monica, age 9 of San Juan wrote:
I tried two times and it works the second time. I used 4 lemons and it worked. Next I will tried with vinegar and chocolate.

Penelopie, age 16 of Corona, AR wrote:
i compared a lemon, bananna, and potato and all of them worked except for the bananna

Lexi, age 11 of Vancouver, WA wrote:
I tried to get a light bulb to light with an orange, lemon, and strawberry. Although the bulb didn't light for any of the fruit(it should have for the lemon) there was an electrical charge for the orange and lemon but the strawberry did notn'

Leeasia, age 13 of Dayton, OH wrote:
This project did not work when I did it, and everything was right but we probably did not have the right clock.

Jackie, age 13 of NC wrote:
i tried more fruits and the lemon worked the best!

Vinh, age 14 of Orlando, FL wrote:
It word because I use one lemonade, one penny and one nickel. I cut two lines then put one penny and one nickel on lemonade then I turn it and it work.

Sakura, age 10 of Mtn. View, CA wrote:
Nothing happened!!! I was so frustrated that it didn't work!!! I even did it as my science project!! Next time I'm doing a glowing pickle!!

Brandie, age 9 of Whitley, KY wrote:
The light glew a little bit.

Myah, age 13 wrote:
i tried it with apples and bananas. The apples and lemons worked but the bananas didn't.

Greg, age 13 of Sylvania, OH wrote:
When I did it, the lemon was able to make the light glow just a little bit.

Danny, age 14 of Flevoland wrote:
I think this is wicked tight I was able to power my room with a little help from my dad. I used about 200 lemons. Weird? I never thought that lemons could power the lighting in my room plus it worked for about 2 days. talk about free electricity!

Jordan, age 13 of Chicago, IL wrote:
The lemon turned the clock on. I didn't just use a lemon. I used oranges, apples, and strawberries.

Tina, age 12 of Huntington, NY wrote:
it didnt work the first time but then I realized I didn't have the clock hooked up right. They should explain th "terminal" thing more clearly but it worked in the end!!!

Vashjken, age 9 of MT wrote:
welll when I tried this experiment I used 1 apple 1 sausage 2 feet of wire a glass bottle and 2 pennies it worked a-mazingly bad. lol

Aj, age 8 of Baton Rouge, LA wrote:
-It shoked me!

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