How to do the Lemon battery experiment
Batteries store chemical energy that can be transmitted as electrical energy through various components in a circuit. You can think of the circuit as the path the electrons (electricity) take. The path must have no breaks in it and it much be a path made of a material that will allow the electrons to flow. Lots of metals meet the requirement although most metals although some are better conductors than others.
Batteries, such as the one we are about to build, have electrodes, or connection points on the battery. The anode is the electrode at which electrons leave the cell and oxidation occurs, and the cathode is the electrode at which electrons enter the cell and reduction occurs. In our battery, the lemon juice acts as the electrolyte which is a solution which is electrically conductive. The electrolyte and electrode components cause a “flow” of electrons to occur as the two metals react with the citric acid in the lemons. When this reaction ends, the battery is dead.
Follow these steps to create a lemon battery.
- Cut three cardboard strips about 1 inch by 4 inch
- Wrap the three strips in aluminum foil
- Cut slits in each lemon about ½ inch apart
- Insert a alumni strip into one of the slits on each of the lemons
- Place a paperclip on the end of the aluminum strip
- In the other slit, place a 4-inch piece of copper tubing
- We will refer to your three lemons as Lemon A, Lemon B, and Lemon C. Using the copper wire, connect one end to the aluminum strip on Lemon A and the other end to the copper tubing on Lemon B. Take another wire and attach to the aluminum strip on Lemon B to the copper tube in Lemon C.
- Attach one end of a wire to the copper tubing on Lemon A. Leave the other end hanging.
- Attach another wire to the aluminum strip on Lemon C. Leave the other end hanging.
- Tape the free end of the wire from Lemon A to the positive terminal on the clock (or the millimeter).
- Tape the free end of the wire from Lemon C to the negative terminal of the clock.
- Wait a few minutes for the current to flow and the clock will begin to run.
If it doesn’t work well, make sure all the connections are good. You might also move the aluminum strips closer to the copper tubes (but not so close that they touch). Also make sure that the lemon has enough electrolyte (juice – dry lemons won’t work).
As explained above, an electrochemical reaction occurs between the aluminum tubing (the anode electrode), the copper tubing (the cathode electrode), and the lemon juice (the electrolyte). This reaction generates an electrical current. Real batteries that you buy in the store work in this exact same manner but use different materials for the electrolyte solution.
Additional notes about the lemon battery experiment
You can take an old penny and an old dime (older coins were made with more pure metals) and stick them into the lemon about ¼ inch apart. Touch your tongue to the coins so that your tongue bridges the gap between them. You will feel the electricity tingling on your tongue.
Lemon battery experiment supplies
Supplies: Tape, Wire (bare), Cardboard, Microammeter, Aluminum foil, Lemon, Paper clip, Copper tubing
Lemon battery experiment picture gallery
Image CreditsLemon battery experiment via Wikimedia Commons with usage type - GNU Free. May 18, 2016
Lemon battery circuit via Wikimedia Commons by Nevit Dilmen with usage type - GNU Free. 2011
LED Lighting by Lemon Battery via Wikimedia Commons by Travis V with usage type - Creative Commons License. April 7, 2010
Making a lemon battery via Wikimedia Commons by Elvira Sagdieva with usage type - Creative Commons License. October 17, 2020
A battery of three lemon cells powering a red LED via Wikimedia Commons by Rupert Swarbrick with usage type - Creative Commons License. October 6, 2012