They could produce about one volt of electricity, long before the invention of this technology.
Of course, there are skeptical people who claim that the batteries are the tools of natural origin. But it is proved that this artifact was created by a human, and the batteries were capable of generating electricity. However, its functionality two thousand years ago raises many questions. But the fact remains.
The metallurgy expert from the British Museum, Dr. P. Craddock, stated that "Baghdad batteries" have always attracted a lot of attention. They are considered as very bizarre invention. He also noted that there have never been found similar artifacts and, most likely, the find was used only once.
By design, the batteries are reminiscent of clay jugs with clogging made of asphalt material, riddled with iron twigs. Most likely, they were filled with a solution of vinegar or wine, or any acidic liquid. Corrosion changes on the inner surface of the vessel indicate that. Acid was used as electrolyte, which helped to generate electricity.
At Smith College in Massachusetts, there was made an exact copy of the "Baghdad Battery". The website reported that the function of the jugs has not been documented, but they definitely were galvanic cells. The scientists from the college believe that batteries could be used to apply one layer of metal such as gold on the surface of another metal, for example, silver. This method is used now in Iraq.