We make the classic copper sulfate and zinc battery using the incredibly easy "gravity" battery design approach. Great for science fairs and similar projects this battery can be used to explore many basic concepts in batteries.
All the components can be gotten from our previous videos:
Copper sulfate: http://www.youtube.com/watch?v=arlYPz3EP7A
Sulfuric acid: http://www.youtube.com/watch?v=okvvD3-DF9U
More information on the chemistry can be googled under the term "daniell cell"
Other science videos at our channel at http://www.youtube.com/NurdRage