How to Make a Penny Battery

Question: What is a penny battery?

This photo was taken by me...  Cruz Flores

Cruz: The name says it all! It's a battery made completely out of pennies. It may be hard to construct for only a small amount of power, but it is still cool and nifty to see what simple components make up a manufactured battery.

Question: What materials do you need?

Cruz: You would need:
-8 pennies (shaven on one side; 1985 and newer)
-LED light
-switch (optional)
-Cardboard
-Vinegar (Salt water mix and soy sauce can also be used)
-File (sandpaper works too)

Question: Why do the pennies have to be shaven off on one side?

Cruz: Well the battery has two main components: electrode and electrolyte. The copper acts as the positive side of the battery, and the zinc acts as the negative side of the battery. So if you did not scratch off one side of a penny to reveal the zinc, your battery would have no negative end and the electrolyte can pass through. The electrolyte in this case is your cardboard+ your acidic liquid.

Question: Okay, so how do I start making my battery?
Cruz: You can start off by cutting the cardboard into small squares slightly smaller than the penny.
Then get the pieces of cardboard soaked in vinegar. As the cardboard absorbs the vinegar, place one penny, shaven side up.
Place one of the wet cardboard pieces on top of the penny. This is one cell. Continue stacking the pennies in the same manner; copper, zinc, cardboard.

Question: What do I do next?

Cruz: Now it's time to see how much power it has! Grab your LED light and place the wires onto the battery. The wire that is slight longer is the positive side, so that will be touching the top of the battery. and the slightly shorter wire will touch the, if you decided to do so, aluminum foil. If not, then it will be touching the bottom of the battery.

Question: How do I show this on paper?

Cruz: Draw a schematic! A schematic is a diagram showing how the circuit runs.

Question: Can I keep the light on forever?
Cruz: Well, not forever. The battery will dry up, and power will stop running to the LED light, but you can seal the battery to slow down the evaporation process by using electrical tape to connect both the battery and the LED light.

Question: What else can I do with the battery?

Cruz: You can create a switch and wire together the battery and the LED light, that way you can turn the light on and off manually.

Question: Is the battery only useful for powering LED lights?
Cruz: Of course not! You can also power a small fan, so you can also make a hand held fan to use on the go!

Question: Was it fun to do this?

Cruz: Definitely! It was a small science lesson and a small life tip to use when there is no power. You can use your spare change to charge your phone! But that requires much more copper and zinc, so start saving up!