Could Ancient Mesopotamians Have Built a Battery?

What if an ancient civilization had built an electric battery nearly 2,000 years before Alessandro Volta? The idea is irresistible. Perhaps that is why the so-called “Baghdad Battery” has become one of archaeology's most debated artifacts. 

Discovered in 1936 during excavations at Khujut Rabu, near Baghdad, the artifacts commonly referred to as the Baghdad Battery consisted of several unglazed ceramic vessels containing a copper cylinder sealed with bitumen—a byproduct of crude oil—and an iron rod inside. The discovery led Wilhelm König, then director of the Iraq National Museum, to suggest these pieces might have functioned as galvanic cells, the basic components of an electric battery. Ever since, the theory has remained suspended between popular fascination and academic skepticism.

"People like to believe in oddities,” says archaeologist William B. Hafford, a research associate at the Penn Museum who has studied the artifact extensively. According to Hafford, the Partho-Sasanian civlizations—which dominated much of the Middle East when the vessels were likely made between the third century B.C. and third century A.D.—possessed the knowledge needed to develop complex technologies. However, he maintains that the available archaeological evidence strongly contradicts the idea that the so-called Baghdad Battery was ever intended to function as a battery. 

Experiments conducted by König and numerous later researchers, have shown that reconstructions of the Baghdad Battery can produce between 0.8 and 2 volts of electricity. In 2005, the TV show "MythBusters" connected 10 replicas and filled them with lemon juice to generate about 4.5 volts.

In 2026, independent researcher Alexander Bazes reignited the debate by proposing that the vessel functioned as “two batteries in one.” His hypothesis argues that the clay jar not only contained the copper-and-iron cell but also served as a separator, generating a second source of voltage. Together, these two mechanisms could have produced about 1.4 volts per unit—roughly equivalent to the nominal voltage of a modern AA battery. Bazes reported that this amount of electricity was sufficient to produce observable effects such as water electrolysis, gas release and changes to metal surfaces.

But many archaeologists say such experiments prove only that a replica can generate electricity—not that the ancient vessels were designed to do so. “Those who reconstruct the supposed battery use a drawing made by König in the 1930s. That drawing shows the vessel and its components assembled as a battery, so of course it works,” Hafford says. The problem is that König never saw the object intact or in its original archaeological context, adds Hafford. “He firmly believed the pieces he saw in the Baghdad museum were of a battery, so he drew it reconstructed in a way that would make a battery,” he explains.

Most archaeologists remain unconvinced that the vessels were ever intended as batteries. "I don't know anybody who thinks it's a real battery in the field," said archaeologist Elizabeth Stone in an interview with NPR.

The Baghdad battery vessels lack key features one would expect in a device designed to generate electricity, Hafford adds. “We don’t find wires, and in the way most of these objects were found, there is no way to attach a contact to the metal core, which remains inside the vessel sealed with bitumen,” he explains. Some examples contain multiple copper or bronze cylinders rather than a single central rod—a configuration that is difficult to reconcile with the idea of a functional electrochemical cell.

Hafford believes the vessels were ritual jars intended to “trap evil spirits.” He considers this one of the strongest interpretations because the vessels were found in the foundations of a building alongside incantation bowls with well-documented ritual functions. In this view, the iron rods would not have served as electrodes but as nails.

The vessels might have been used to hold prayers or incantations inserted through the neck before they were sealed and buried as part of a ritual practice. Hafford points to the discovery of so-called “witch bottles,” ritual containers used centuries later, as a comparison. They may have served a ceremonial purpose similar to that of the ancient Mesopotamian vessels. “People don’t like that interpretation, so they go only on the evidence of one example that König interpreted,” he says.

However, the mystery continues. In 2003, many of the original artifacts disappeared during the looting of the Iraq Museum in Baghdad. What remains today are photographs, reconstructions and a debate that, according to Hafford, reveals as much about modern perceptions as it does about the ancient world.