Lemon-Powered Light

Did you know that you can easily make a homemade battery?

It’s not hard at all. You don’t need to buy any special equipment for that.

Ok, you may need some equipment, but I bet you can get them by rummaging the house (that’s what I did 🙂 ).

I guarantee your kids will be all awe struck!

lemons (I used 4 of them. In general, the more you use, the more power can be generated)
low voltage LED light bulb (you can buy this or get it from an old Christmas string light decoration. I got mine by taking apart this flashlight keychain)
copper wire
galvanized nails (you need the same number of nails as the number of lemons)
electrical wires (This one is harder to scour in the house. So I used electrical wires with alligator clips.)
adult supervision

Warning: Do not consume the lemons after they are used in the experiment!!

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.

Obviously, this lemon battery cannot power up a camera or even a kid’s toy. As you can see, our LED only lighted up slightly.

But it is a fabulous experiment to demonstrate how direct current (DC) can be generated.

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.