Baghdad Battery – 250 BC
The Baghdad battery seems like something that should not have existed 2,000 years ago because human understanding of electricity did not come until centuries later. But while the purpose and use of the Baghdad battery is not known, the object does have the ability to function as a battery. There are archaeologists and scientists who vehemently disagree over whether or not these artifacts were ancient batteries, but despite this the object maintains the name of battery.
The artifact was found in Khujut Rubu’a, just outside of Baghdad. It consisted of a clay jar with a stopper made from asphalt. Through the center of the asphalt was an iron rod that was surrounded by a copper cylinder inside the pot. The pot could then be filled with an electrolytic solution such as vinegar, lemon juice, or grape juice. Once filled with the liquid, the battery produced 1.1 volts of electricity.
There are a number of theories posited by archaeologists and historians about what the small battery could be have been used for. Some prominent theories propose that the battery was used for electroplating. The theory comes from a number of very fine silver objects that were uncovered from ancient Iraq. These silver objects had been plated with very thin layers of gold which some believed had been done by electroplating using the battery.
There are controversies surrounding the battery. The first is that the batteries that were uncovered could not actually produce a charge. Some claim that this is because the batteries have degraded over time. Others see this a proof that they were never meant to be a battery but rather used as storage for scrolls. There were similar artifacts found for scroll storage but that were without the outer clay jar. It was argued that the acidic organic material found within the battery was actually the remains of a scroll that had deteriorated and not acidic material used to produce an electric current.