Baghdad Battery — who made it?

The Baghdad Battery is the common name for a number of artifacts found in Mesopotamia (a part now largely corresponding to modern Iraq), possibly created during the Parthian or Sassanid period (the early centuries AD). These jars were probably discovered in 1936 in the village of Khuyut Rabbou’a, near Baghdad, Iraq. In 1940, Wilhelm König, the German director of the National Museum of Iraq, published a paper speculating that they may have been galvanic cells, perhaps used for electroplating gold onto silver objects. This interpretation continues to be considered as at least a hypothetical possibility. If correct, the artifacts would predate Alessandro Volta’s 1800 invention of the electrochemical cell by more than a millennium.

Because of this, it is considered by specialists to be an OOPArt (Out-Of-Place Artifact). One wonders: Is that a surviving proof of a prehistoric advanced society long gone? and if so, was that advanced society human or not? or was it dropped onto Earth by other intelligent creatures that live elsewhere?

Wikipedia:
Baghdad Battery
Out-of-place artifact