Introduction: Potato Battery
So I have been interested in electronics and batteries in specific for a while, Telsa's recent announcement of their new "tabless" battery has rekindled that interest. So once I saw this challenge I figured I would take this opportunity to explain a little bit about how to make your own potato battery and why it works.
Any kind of wire
Anything that copper (I'm using a penny)
Anything made of zinc (most machine screws are plated with zinc to stop it from rusting)
Step 1: Preparing Your Potato an Penny
To prepare everything you'll want to wrap the red (or black, it doesn't matter, but because I know the penny will end up as our +lead we'll use red) around the penny and wrap the black wire around the screw. You'll next need to cut a small slit into one end of the potato, make sure its long and deep enough to fit the penny.
Step 2: Stick Em in the Potato
Simply stick the penny with wire attached, into the slit you made earlier and screw the screw into the opposite end of the potato. That's it, you've made a battery!!
Step 3: Testing It
You've made a battery, but your not quite sure if it works. To test it take out your multimeter and turn the knob to DC voltage(DC is shown by a dotted line under a straight line, AC is a curvy line under a straight line) that DC is important it won't work if its set to AC. When your multimeter is ready just touch the red lead to the read wire and the black lead to the black wire. I got a reading of .85 volts, because potatoes aren't standard sizes you will get a slightly different number but it should be in the same ballpark.
Step 4: What's Happening?
Seeing as I am an electrical engineer major I'm not terrific at chemistry but I know enough to explain the basics of how this battery works. The penny is called the cathode and the screw is called the anode, the zinc in the screw reacts with the electrolyte ( an electrolyte is just some substance that will react with the metals and helps balance everything, in this case, its just the potato juices) and decides to give away an electron. at the same time, the penny reacts with the potato juice and decides it really wants an electron, so when we connect them together with a wire the electrons can go from the screw over to the penny. If you were to put a light between the anode and cathode then the electrons would have to go through the light before it gets to the cathode. That is why I said earlier to use the red wire on the penny because I knew that the copper in the penny would make it the cathode and red is commonly used to show the cathode lead. this is a simple explanation of how all batteries work just with different materials as the cathode and anode and electrolyte.
Step 5: Lets Light Things Up
Ok now we know how this thing works lets make it work for us. I have this small led that needs 1.8 volts and 20 mA now I already knew this wouldn't work but i connected it up and sure enough no light. You might be thinking "Of course not it needs 1.8 volts" that's actually not why, yes, it needs 1.8V but if i only gave it .85V it would still light up just not very bright. The real reason is that the potato doesn't have 20mA to give, mA is Milli amperes. Amperes is basically the storage size of a battery(yes I know this isn't technically what it is but its a good enough explanation). the potato simply does not have enough Amps to power this LED.
Step 6: Congrats, Your Done.
Congratulations! you now know how batteries work and have made one yourself. I want to clarify a couple of things, just because we couldn't power a LED with this one potato there are many things we could've powered but I just didn't have on hand. I've seen kits that come with a little clock, or with a smaller led, and if you are bent on lighting up that led you could make multiple potato batteries and tie all the red wires together and the black wires together, to give it a higher amperage. I would like to thank you for your time and if you learned something please consider leaving a vote for this. You could take a look at the other projects I've done on my instagram https://www.instagram.com/kwood_creations/ Thanks!
Step 7: One Last Thing
Hello, I'm here to tell you one last little secret. this works with other fruits or veggies too, WHAT!! it's true, if you follow the same steps but substitute the potato for say, an apple, it'll work the same. I even got a higher voltage when trying a small cup of lemon juice than I did for an apple or potato. ok, that's it, I promise, goodbye.
Participated in the
Potato Speed Challenge