The beginning of the nineteenth century brings us at last to the question: who invented the battery? The short answer is that in 1799, an Italian named Alessandro Volta, created the first device recognizable as the modern battery.

The long answer is all of the history of electricity that you’ve read up to this point, as well as the work of Luigi Galvani.

To understand how Volta made his discovery, it’s necesssary to understand the state of the electrical theory in the late eighteenth century. The theory had been limited to electrostatics before Benjamin Franklin’s experiments revealed current electricity. In explaining the origin of electricity, scientists followed their national prejudices. British scientists adhered to the single fluid theory advanced by Franklin. The French, additionally influenced by the physics advances of Pierre Simon LaPlace (1749-1827),  adhered to Coulomb’s two-fluid theory. The Italians opposed Coulomb’s theory. But in the late 1700s, the revolutionary experiments of Luigi Galvani (1737-1798), a physician, anatomist and professor at the University of Bologna, would bolster the world’s knowledge of current electricity, creating a platform that Alessandro Volta would build on.

Galvani and his wife Lucia were dissecting frogs near an electrostatic generator when they noticed that as Lucia placed the scalpel into particular muscles, they contracted violently. This observation spurred Galvani to investigate, and he soon found that two metals placed in contact with the frog’s muscle would cause it to twitch. Galvani termed his discovery “animal electricity,” and published a work in 1791 detailing his experiments (De viribus electricitatis in motu musculari commentarius). To explain animal electricity, Galvani hypothesized that the frogs’ legs contained a sort of electric fluid, which was retained after death. Thus Galvani discovered current generated by a chemical action, or galvanic current.

(Galvani’s work inspired Mary Shelley to write Frankenstein, in which dead flesh is reanimated using lightning; the term galvanism originally referred to this process but has fallen out of use. Galvani’s name now survives in the word galvanization: the process of electroplating metals, typically steel, with other metals, usually zinc and chromium, to prevent corrosion.)

When Alessandro Volta read Galvani’s work, he was unsatisfied by Galvani’s explanation for the electricity’s origin. Volta was well-positioned to comment; he had already experimented extensively with electrostatics and he had improved and popularized an electrostatic generator operating through induction, the electrophorus. (Volta is often credited with inventing the electrophorus, but it was actually invented in 1764 by Swedish scientist Johan Carl Wilcke.)

Through repeating Galvani’s experiments, Volta realized that electricity was only produced when two different metals were used in the circuit, and that some metal combinations produced more twitching than others—an important discovery in the creation of the battery.

Volta paired different combinations of metals and tested the electrical charge produced between them with an electrometer. He discovered the following combinations:
POSITIVE    NEGATIVE
Zinc                Copper
Lead               Silver
Tin                 Gold
Iron                Graphite

Through further experimentation, Volta realized that fluid facilitated the electrical flow. Volta then placed a piece of tinfoil and a silver coin on his tongue and noticed a sour taste; he tried it again with a silver spoon and a copper wire and got a similar result. He even placed a metal on his forehead and another in his mouth and claimed that he saw a flash in his mind. Based on the experiments with placing the metals in his mouth, he realized that a liquid would improve conductivity. He tested a number of liquids before choosing a strong solution of saltwater, brine, and soaking cardboard discs in it. He then stacked zinc and copper pairs between cardboard discs, producing the voltaic pile—the first battery. The year was 1799.

The famous couronne de tasses, or “crown of cups” experiment, was Volta’s next battery form. The first version was a series of cups filled with brine daisy-chained together with alternating pieces of zinc and silver. The second version consisted of a voltaic pile connected to a cup of brine to keep the cardboard discs moist. Finally, the third version connected two voltaic piles with two cups of brine.

Volta’s pile showed the dramatic difference between galvanic and static electricity. Unlike electrostatic electricity and lightning, there was no flash of power. The galvanic electricity of the voltaic pile was low voltage but high amperage. These terms were not yet in use; Volta said that the pile had low electrical tension but high current. In contrast, frictional electricity has high voltage and low amperage.

Volta himself was unsure of the source of the voltaic pile’s power and reverted to the fluid theory; he theorized that the metal combinations were somehow freeing static electrical fluid which then traveled through the whole pile.

In 1801, Volta gave a series of lectures and demonstrations in Paris, where he was assisted by Napoleon Buonaparte himself, who was at that time a member of the Institut de France. Volta was awarded a special gold medal and a pension, the first of many honors.