Watch this science video tutorial from Nurd Rage on how to make copper sulfate and zinc batteries. They show you how to 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.
More information on the chemistry can be Googled under the term "Daniell cell".
Brought to you by one of WonderHowTo's favorite scientists NurdRage.