Banana Battery (Voltaic Pile)

prusaprinters

IntroductionBuild this voltaic pile to learn how batteries work! Zinc washers act as the anode and copper washers act as the cathode. Banana slices are the electrolyte. You could also use pickle slices, but make sure they aren't too wet (liquid could cause a short between anode and cathode layers). Stack more zinc-banana-copper layers to increase the voltage. I found that using 4 banana slices (as pictured) provides enough voltage to turn on an LED. This design is inspired by the original voltaic pile invented by Alessandro Volta in 1800 (https://en.wikipedia.org/wiki/Voltaic_pile)Parts ListIn addition to the printable parts, the following hardware is needed:Copper washers (0.5" diameter or smaller, McMaster-Carr)Zinc plated washers (0.5" diameter or smaller, McMaster-Carr)1 banana or pickleCopper foil tape (for optional terminals - this makes it easier to connect to the anode and cathode, Amazon)2 screws and 2 nuts (for optional terminals - this makes it easier to connect to the anode and cathode)Voltmeter (optional - this helps determine the voltage being generated by the voltaic pile)LED (optional - things are always better with LEDs!)Assembly InstructionsPrint the base, two contact plates, top plate, three nuts, and screw. Slide one contact plate onto the base, then layer washers and banana slices as follows: zinc, banana, copper, zinc, banana, copper, etc… The more washer banana sandwiches you make, the more voltage you will generate. Top off the “pile” with the other contact plate and then place the top plate on top of the base. Use the three nuts to secure the top plate to the base, and then screw the screw into the top plate. Keep tightening the screw until it makes a firm connection to the top contact plate. There should be a voltage potential between the top copper washer and the bottom zinc washer.Optional: to make it easier to connect things to the battery, cover each contact plate with copper foil tape. Use a screw and nut to make terminals that are electrically connected to the copper foil tape on each contact plate. You can now connect to the voltaic pile using these terminals.