In 1938 an archaeologist in Iraq acquired a set of clay jars that had been excavated two years earlier by villagers constructing a railroad line. The vessels were about 2,200 years old. Each clay jar contained a copper cylinder surrounding an iron rod. The archaeologist proposed that the vessels were ancient electric batteries and even demonstrated that they can produce a small electric current when filled with some liquids. However, it is not likely that the vessels were actually used as electric batteries in ancient times.
First of all, if the vessels were used as batteries, they would probably have been attached to some electricity conductors such as metal wires. But there is no evidence that any metal wires were located near the vessels. All that has been excavated are the vessels themselves.
Second, the copper cylinders inside the jars look exactly like copper cylinders discovered in the ruins of Seleucia, an ancient city located nearby. We know that the copper cylinders from Seleucia were used for holding scrolls of sacred texts, not for generating electricity. Since the cylinders found with the jars have the same shape, it is very likely they were used for holding scrolls as well. That no scrolls were found inside the jars can be explained by the fact that the scrolls simply disintegrated over the centuries.
Finally, what could ancient people have done with the electricity that the vessels were supposed to have generated? They had no devices that relied on electricity. As batteries, the vessels would have been completely useless to them.
Your reading says that these vessels were not used as batteries in ancient times. But the arguments used in the reading are not convincing. The battery explanation could very well be correct.
First, about the absence of wires or other conductors. Remember: the vessels were discovered by local people, not archaeologists. These people might have found other material located near the jars, but since they were not trained archaeologists, they may not have recognized the importance of that material. So material serving as wires or conductors might have been overlooked as uninteresting or even thrown away—we will never know.
Second, it’s true that the copper cylinders in the vessels are similar to the cylinders used to hold scrolls. But that does not really prove anything. It’s possible that the copper cylinders were originally designed to preserve scrolls, and that some ancient inventor later discovered that if you use them together with iron rods and some liquid in a clay vessel, they will produce electricity. That’s how the first ancient battery could have been born. In other words, the copper cylinders could have been originally used for one purpose but then adapted for another purpose.
Finally, there’s the question of the possible uses of the battery in the ancient world. Well, the battery could produce a mild shock or tingling sensation when someone touched it. This could very well have been interpreted as evidence of some invisible power. You can easily see how people could convince others that they had magical powers through the use of the battery. Also the battery could have been used for healing. Modern medicine uses mild electric current to stimulate muscles and relieve aches and pains. Ancient doctors may have used the batteries for the same purpose.