If you are ever feeling creative and wishing you were slightly more like MacGuyver, who can make anything from anything, give this one a try. A rudimentary battery cell can be made from three simple items: a fresh juicy lemon, a galvanized nail, and a penny. The zinc from the galvanized nail, the copper from the penny, and the citric acid from the lemon will combine to create a very small electric current that can be used to power an LED light (a Light Emitting Diode).
To begin, insert the galvanized nail partially into one end of the lemon. Take care not to insert the nail too far in; just far enough to make contact with the lemon juice inside the lemon. At the other end of the lemon, make a small incision and insert the penny partially so that the penny makes contact with the lemon juice within. You must ensure that the nail and the penny do not touch one another or the battery will fail to work.
Once you have inserted the galvanized nail and the penny into the lemon, your rudimentary battery is complete. The nail and the penny will form the battery’s terminals, which you can attach to a low powered LED to turn the electrochemical energy in the lemon battery into light. If you find that one lemon does not produce enough voltage to light the light adequately, two or more lemon batteries can be connected end to end (remember that each battery has a positive and negative terminal, and they must be connected positive-to-negative) to form a multi-cell battery with higher voltage. To attach the LED to the lemon battery you will probably also need some alligator clip wire test leads that should be available at any electronics supply store. It may take as many as two or three lemon batteries connected in series for the LED to light demonstrably.
The lemon battery makes a fun, five minute project that one can do with the kids or just for your own self-interest. While you won’t be able to power your house from a collection of lemon batteries, ask your local electronics store what other things you might be able to get a lemon battery to power, such as a miniature hobby motor or a small transmitter. The possibilities are endless, but you will soon discover that the lemon battery’s potential is lackluster at best for most applications. It makes a fun science project to teach your kids about electricity, though, and you could even incorporate a switch into the circuit with the LED to teach them about basic circuits. Good luck with your lemon battery project, and happy MacGuyvering!