Think chemical energy is dull? Think again! Potato batteries are shockingly fun to make and this project is easy to do at home! The project is perfect for ages five and up, but younger children will need adult supervision and help working with the nails and wires.
If you want to learn how to make a potato battery, we show you how to conduct this experiment!
Potato Battery Instructions
A potato battery is a great activity to illustrate the transfer of energy, from chemical to electrical energy. It takes about 15 to 20 minutes to complete from start to finish.
- Two potatoes
- Two copper wires
- Two pennies
- Two galvanized nails
- Multimeter with one black wire probe and one red wire probe
For a nail to be galvanized, it needs to have a zinc coating. This is designed to prevent rust and corrosion. Make sure to look for the word "galvanized" when shopping for this material, otherwise the experiment won't work.
- Cut out a penny-sized hole inside of a raw potato.
- Strip one end of a copper wire (make sure to remove a few inches of plastic).
- Tie a copper wire around a penny, making sure the stripped end is touching the copper. You should wrap the wire around the penny a few times.
- Place the penny and copper wire unit into the hole of your potato.
- Pierce the potato with a galvanized nail on the opposite side of the potato as the penny.
- Follow steps one through five with a second potato, penny, copper wire, and galvanized nail.
- Place the two potatoes side by side.
- Wrap the copper wire from one potato around the galvanized nail of the other potato.
Does Your Battery Work?
So now you've made your potato battery, but what should you do with it? There are a variety of things you can do to see if your battery works and how it might be used.
- Use a multimeter. A multimeter measures voltage. All you need to do is touch the multimeter's probes to the nail and penny.
- Use your potato to power something. You can use LED lights, a light bulb, a simple clock, or anything else small that requires a battery. This is easiest to do if you use alligator clips to help connect your battery to the battery terminal of a small device. Keep in mind a potato battery isn't strong enough to power anything large.
More potatoes equal more power! If you want to power something larger, repeat the steps above to create a longer circuit and give your object some more juice!
Potato Battery Experiment Variations
There are a few variations you can try with this science experiment. All of them are appropriate for any age. However, small children will require adult supervision and guidance.
- Try boiling or cooking the potato first to see if this increases the output or voltage.
- Try the experiment with a lemon, an orange, or a pickle.
- Soak your potato in salt water before setting up this experiment. See how much extra voltage it gains from this salty soak!
- Determine how much energy comes from each potato battery. Add additional potatoes (with pennies and galvanized nails in them) one by one and measure your increase your voltage. This is easily done by attaching the potatoes to each other with copper wires (see video) and measuring the increases in voltage with your multimeter.
- Determine if a cleaner penny can conduct more electricity than a dirty one. This is a great way to introduce more science concepts to your kids.
Why Your Potato Battery Works
The reason potato batteries work is because chemical reactions are taking place between the zinc in the nail, the copper in the penny, and the acids in the potato. Essentially, this experiment changes chemical energy into electric energy.
Teach Engineering notes that potatoes create an electrolyte solution. This means that zinc's electrons have a way to move to the copper. Then, the attached wire allows the electrons to move from the copper back to the zinc. This creates a complete circuit allowing for a "flowing path of electrical energy."
Learning About Electricity Can Be Fun
The potato battery experiment provides an excellent way for kids (and adults) to learn more about science. Now that you've made a potato battery, you know more about how a circuit and electricity works!