Video narration
This object, called the “Baghdad Battery,” was found near Baghdad, Iraq: a clay jar with a copper cylinder and an iron rod inside. Some researchers think that, filled with an acidic liquid like vinegar, it could produce a small electric voltage—like a simple battery. That electricity might have been used for experiments or to electroplate metal with a thin coating. But the interpretation is contested, and it may have had a different purpose entirely. It’s usually dated to the Parthian or Sasanian era, around two thousand years ago.