One day in 1936, a clay vessel similar to a jug was found. It turned out to be an ancient battery, 13 centimeters tall. Concealed inside this element was a copper cylinder and an iron rod. In reality, it was a regular salt battery.
Today, this find is housed in the Baghdad History Museum. Some experts believe it's the oldest battery ever found, while others simply can't understand how such a thing is even possible. The battery is approximately 2,000 years old and was functioning perfectly well 250 BC.
The ancients used this device to apply various coatings to metals, such as gold, silver, or copper.
Scientists hypothesized that such a battery could produce up to 1 volt. After some theoretical considerations, they decided to conduct an experiment. They constructed a similar jug and filled it with wine vinegar. The device showed that the vessel was capable of producing 0.5 volts. Then, in 1947, another researcher decided to use copper sulfate as an electrolyte. His experiment resulted in a voltage of a whopping 2 volts! Then someone suggested using lemon juice, and the researchers ultimately reached the maximum limit of 4 volts.
