The Baghdad battery thing isn't that mysterious. The Ancient Egyptians used electrolysis to remove the hair from their heads and bodies as was the fashion at the time to prevent infestations of lice and other parasites, and Ancient Egyptian priests did it for religious reasons. This is likely a battery that made it out of Egypt and into Baghdad.
ooh! Mysterious! LOL
people need to be more skeptical. There are natural and logical explanations for everything, even if we don't know yet what they are.