A battery, which is actually an electric cell, is a device that produces electricity from a chemical reaction. Strictly speaking, a battery consists of two or more cells connected in series or parallel, but the term is generally used for a single cell. A cell consists of a negative electrode; a positive electrode and an electrolyte, which conducts ions.In the year 1800 Alessandro Volta invented the voltaic pile and discovered the first practical method of generating electricity. Constructed of alternating discs of zinc and copper with pieces of cardboard soaked in brine between the metals, the voltaic pile produced electrical current. Alessandro Volta's voltaic pile was the first "wet cell battery" that produced a reliable, steady current of electricity.
Since then varieties of batteries are made for commercial or specialized uses. Different batteries use different electrodes and different electrolytes. Some electrolytes contain corrosive or otherwise hazardous substances.
Making batteries and producing electricity is among the most exciting and educational experiments that students can try as their school project or science project. To avoid exposure to hazardous chemicals, ScienceProject.com recommends using household materials such as saltwater, lemon juice and other fruit juices or fruits as electrolytes.
Light up a light bulb!
Although challenging, you can make enough electricity from fruits to light up a small light bulb. To be more precise, it's not the physical size of the light bulb that matters. You really need a light bulb that requires very low voltage and very low current.
What is voltage and what is current?
Electricity is a flow of electrons (almost like a flow of water). Voltage is the speed or pressure of electrons (like the pressure of water in a pipe or the speed of water exiting the pipe). Current is the ratio of the flow. (A river has a larger current than a narrow pipe. The total amount of passing water is a function of the current and speed.)
This project is also a good practice for learning about electric current and voltage. Some light sources require high current and low voltage while others may require high voltage and low current. The order in which you connect fruit batteries may result either higher voltage or higher current.
What materials do I need?
The materials you need for making fruit batteries and performing related experiments are:
Using a kit
You may find it to be a big saving when you buy the materials as a kit. MiniScience.com has a kit for this project called "Make Electricity Science Kit".
Some experiments in this page have used copper sulfate solution. Copper sulfate is not included in your kit, but is usually available from pool suppliers and hardware stores.
|Don't Install the battery
Your multi-meter comes with a battery, however you will not need to install battery for this project. Your potato or lemon will make enough electricity for the meter to work. Set your meter to 2.5 DCV. This setting is for Direct Current Voltage measurement up to 2.5 volts.
Read the voltage on the line that reads from 0 to 250 and divide it by 100 to get the real voltage.