The Baghdad Battery

Overview

The Baghdad Battery (also called the Parthian Battery) is a set of artifacts discovered near Baghdad, Iraq, in 1936. A clay jar approximately 13 cm tall contained a copper cylinder and an iron rod, sealed with asphalt. It has been dated to the Parthian period (c. 250 BC - 224 AD).

Key Discoveries

Discovery and Early Research

In 1936, German archaeologist Wilhelm Konig studied the artifacts at the Iraq Museum in Baghdad and proposed that they might be galvanic cells (batteries). When filled with an acidic liquid such as vinegar or wine, the jar could reportedly generate approximately 1-2 volts.

Replication Experiments

Multiple experiments, including those on MythBusters, have confirmed that replicas can indeed generate a weak electrical current. However, the power produced is very small, limiting practical applications. The most popular theory is that they were used for electroplating (gilding with gold or silver), but no ancient Mesopotamian plated artifact has shown evidence of electroplating.

Proposed Hypotheses

An ancient battery used for electroplating
A ritual device that produced a religious sensation through mild electric shock
A storage container for scrolls or documents, unrelated to electricity
A tool created for another purpose that coincidentally resembles a battery

AI Analysis

Scientific Explanation

While replicas do produce weak electrical current, there is no evidence that ancient peoples understood electrical principles. Ancient Mesopotamian gilded artifacts can be explained by mercury gilding (fire gilding), eliminating the need for electroplating. Poor documentation of the discovery context, including uncertain dating and provenance, complicates assessment. The "battery" interpretation is likely retroactive, and the artifacts probably served a different original purpose.

Alternative Theories

The weak current accidentally generated by the combination of acidic liquid and metals may have been used as a medical device for pain relief, similar to electro-acupuncture.
Rather than a battery, the vessel may have been a sealed container for protecting and storing papyrus or leather scrolls, with the asphalt seal serving as moisture protection.
The vessel may have been used for manufacturing fragrances or chemicals through fermentation or chemical reactions, with copper and iron combined to facilitate specific reactions.