Ok, the above image is a bit of an exaggeration, but batteries do generate electricity (so to speak) by using two dissimilar metals and an electrolytic solution. This is the same principle that is used to turn veggies into batteries since vegetables and fruits are filled with natural electrolytic material, the most important component for electrically charged ions to move from one “pole” to another. In other words, they can help electric current to flow under the right conditions.
Potatoes are popularly used for making batteries with as many pairs of dissimilar metals as there are potatoes. The metals need to have sharp edges so that they can easily cut through the potatoes and make necessary contacts.
While copper and zinc are the most common metal choices, you can also try other metal pairs like copper and aluminium, copper and iron, aluminium and iron and so on. You’ll need as many short pairs of wire stripped at the edges as metal pairs. You also need an LED light preferably a red one as it’s more visible in daytime and requires minimum voltage for bright illumination.
Clean the potatoes and metal pieces to remove mud and dust particles. Scrub the metal pieces with sandpaper for a polished look. Secure the potatoes in containers and align them. Alternately insert the metals, starting from the first potato to the last.
Use the given wires and a soldering iron to connect the alternate metal strips from one potato to the other so that two ends of metals from the two extreme potatoes are free and open.
Add longer pieces of flexible wires to these ends and connect to the LED. If all connections are properly done, the LED will instantly give a bright glow, proving that there’s a reaction between the metals and potato’s electrolyte and a battery is formed!
Other fruits and vegetables
Not only potatoes, even lemons can generate electricity using similar metals, wires and an LED light. But lemons are more efficient at generating electricity as they are acidic in nature. Even bananas and strawberries can be made into batteries using the same principle.
Potatoes are most popular as they are rich in phosphoric acid, easily available and can be stored for months without attracting insects because of its sturdy starch tissue.
Or for a more prepared experiment, try one of these project kits …