Most sources date the batteries to around 200 BC - in the Parthian era, circa 250 BC to AD 225. Skilled warriors, the Parthians were not noted for their scientific achievements.
"Although this collection of objects is usually dated as Parthian, the grounds for this are unclear," says Dr St John Simpson, also from the department of the ancient Near East at the British Museum.
"The pot itself is Sassanian. This discrepancy presumably lies either in a misidentification of the age of the ceramic vessel, or the site at which they were found."