Did you know that you could easily make a battery at home?
You can do that by using lemons.
Lemons are sour and carry a lot of citric acid.
Of course, they cannot power your refrigerator or a toy car.
But they contain enough energy to power a small LED light and make it light up a bit.
This experiment is not hard at all, but you do need a few special equipment.
They are listed at the end of the instructions below.
Try it. I guarantee your kids will be awestruck with this lemon lightbulb!
- lemons (You can start with 4. In general, the more you use, the more power can be generated)
- low voltage LED light bulb (you can buy small LED diodes or get one from an old Christmas string light decoration)
- copper wire
- galvanized nails (the same number as the number of lemons used)
- electrical wires or alligator clips
- wire cutter
- adult supervision
- Roll and squeeze the lemons a little bit by hand to release the juice inside.
- In each lemon, insert 1 nail and 1 small strip of copper wire. Leave a small section in each one out for the electrical wires to connect.
- Using an electrical wire, connect the nail in one lemon to the copper strip in another lemon. Do this to each lemon to form a chain.
- In the first lemon, connect the copper to the long leg of the LED light. In the last lemon, connect the nail to the shorter end of the LED light (the shorter leg comes out of the flat side of the LED).
- Voila! You have made a battery.
Batteries are made of two different types of metal suspended in an acidic solution.
In this experiment, copper and zinc (galvanized nails are zinc-plated) are the two metals and the lemon juice is the acidic solution.
An electric current is created when the two metals have different tendencies to lose the negatively charged electrons.
Because zinc loses electrons more readily than copper, zinc is the negative electrode (anode) and copper is the positive electrode(cathode).
When the battery is connected with a LED bulb, the circuit becomes closed.
Electrons flow from the zinc electrode through the LED bulb to the copper electrode and the bulb lights up.
Now it’s time to explore more. Can you try the experiment again with the following modifications and see what differences they make?
- Use a different type of fruit.
- Use other substances such as a vegetable or a cup of tap water as the conducting solution.
- Use different metals as the electrodes.
But it is a simple experiment to demonstrate how direct current (DC) can be generated.
- Electrochemical Cells by HyperPhysics, Department of Physics and Astronomy, Georgia State University