Quote Originally Posted by n2ize View Post
The problem, with the Persian/Bagdhad cell is that it has no external cathode connection. My guess is that it wasn't a cell at all.
Your guess and that of just about every serious archeologist. Since the copper and iron were both completely covered by the asphalt sealant, it seems very unlikely that the thing was used as a battery. The most likely scenario is that they were used to store important documents and that the acidic residue found in the jars was probably decomposed papyrus.