When perusing websites such as Instructables for interesting electronic projects, you'll find dozens of instructions on how to make a low-tech battery known as a Leyden Jar, usually with an empty jar, aluminum foil, and a long nail.
There's many reasons why the Leyden Jar (which is technically a capacitor, rather than a battery proper) is so popular on these creative maker websites.
First, they can be made with almost any material. A Leyden Jar works by absorbing static electricity and storing it via the gap between two coatings of metal on the outside and inside. As long as you have two pieces of metal that can conduct static electricity and a non-conductive container, you can make a Leyden Jar with them. The earliest Leyden Jars were even made usingsalt water and the human hand, which can both conduct static electricity!
Secondly, Leyden Jars, have a long, dramatic history. They were the first devices ever created that could reliably store and discharge static electricity: pioneering scientists such as Benjamin Franklin used Leyden Jars to experiment with electricity and learn about it's properties, efforts that led to the technology of our modern day society.
Thirdly, Leyden Jars can be very entertaining, due to their ability to give off a mild electric shock, 'Joy-Buzzer' style. During the late 18th century, a party game fad arose where guests at a party took turns getting shocked by a Leyden Jar, or held hands and let the static discharge from a Leyden Jar travel through several people's bodies. During the 19th century, there were even stage magicians who would build Leyden Jars into their canes in order to 'levitate' pieces of paper and foil or ignite pyrotechnics without matches!
Here then, is a simple Leyden Jar that can be made in a few easy steps, requiring only:
An empty glass spice jar, a long nail, aluminum foil, electric tape, and a pocket knife to cut things out.