Alien Artifacts?

For years archeologists have been digging up strange things but one day in 1936 a stange looking object was unearthed near a village in Bagdad, it was a jar made of clay which inside had a cylinder of sheet copper which had an iron rod suspended at the centre of it. No one knew what it was so it was put on display at the Cairo Museum in Egypt. Some people who saw the strange looking object commented on how it looked like an electric cell. Ufologists called this proof that technical knowledge had been passed on by space travellers!

In 1976 a team of german scientists made a copy of the artifact and filled it with grape juice a good source of acid. It produced a current of two volts. The original battery maybe as old as 2,000 years so how did the race know how to build it? Where did they get the knowledge from? and what did they use it for?