Children across the country have learned to make batteries out of potatoes. I learned to do this when I was a kid. To be honest, I thought it was just some kind of sleight of hand that my teacher learned from his colleagues. I was wrong.
Now in my 50s, I decided to look into the potato battery to find out exactly how it works. It's actually simpler than you might think. A potato battery takes advantage of a chemical reaction between copper wire and the zinc coating of a galvanized nail.
To operate the potato battery, you will need at least two potatoes. Pale Blue Earth, a Utah company that sells USB-rechargeable lithium-ion batteries, says potatoes perform the same function as the electrolyte in one of their rechargeable batteries.
In addition to your two potatoes, you will also need:
You start by cutting a small notch in one of the potatoes. Then wrap one of your pennies in copper wire and insert it into the notch. Leave some of the wire protruding from the potato. Then, drive a galvanized nail into the opposite side of the potato. Half of your battery is depleted.
Now repeat the process with the other potato. When you're done, connect the copper wire from one potato to the galvanized nail from the other. You now have a working battery. If you were to connect a voltmeter between the open nail of one potato and the copper wire of the other potato, it would register the voltage. You can use your potato battery to power an LED bulb.
Although potato batteries don't produce enough electricity to be useful, they are a good illustration of how batteries actually work. As you know, potatoes do not store electricity. Neither do copper wires, galvanized nails or coins. So what's going on?
There are certain materials in both galvanized nail and copper/penny wire. When these materials come together, they create a reaction capable of producing electricity. This reaction needs a conduit through which the ionic energy can flow. Potatoes serve as a conduit.
In a real battery, you have an electrolyte solution between the two ends of the cell. A lithium-ion electrolyte solution is based on lithium salts. The positive end of the battery is the cathode; the negative end is the anode. These two ends are comparable to the copper wire and the zinc nail in your potato battery.
When these two ends meet in a closed circuit, they create a chemical reaction within the electrolyte solution. This chemical reaction generates electricity.
Hope you now have a basic understanding of how the potato battery works and why this is a great illustration of how lithium-ion batteries work. But there is another trick you can try. Grab some extra potatoes and use them to create additional battery setups. Connect them all in one line - galvanized nail copper wire.
When you're done, check them with your voltmeter. You should notice a higher reading than what you got with just two potatoes. Indeed, each potato you add to the series increases the tension.
Potato batteries really work. It may sound primitive, but building such a battery is a useful way to understand what's going on with the batteries that power our cell phones, flashlights, and electric toothbrushes. Batteries really aren't that complicated when you break them down into their basic components.
