Meet the Irish Priest Who Built the World's Largest Battery in 1848

Part 1 of our Irish Renewable Energy Pioneers series

Long before "renewable energy" was a buzzword, a Catholic priest in County Louth was tinkering with electromagnets, batteries, and coils in a seminary lab, quietly laying groundwork for the electrified world we live in today.

Fr. Nicholas Callan (1799–1864), professor of natural philosophy at Maynooth College, wasn't just saying Mass and teaching Latin. Fascinated by the emerging science of electricity, he spent decades building bigger, better, and frankly more dramatic versions of the era's batteries and magnets. In 1848, he wired together 577 cells into a single battery, reputedly the largest in the world at the time, and used it to instantly electrocute a turkey in front of a packed Maynooth lecture hall on 7 March. His giant horseshoe electromagnet, still on display at the college, could lift over a tonne.

But Callan's real legacy is the induction coil. By winding a primary and secondary coil around an iron core and cleverly separating them, he discovered in 1836 that a small battery could produce a massive "stepped-up" voltage, essentially working out the principle behind the modern transformer years ahead of his peers, including Michael Faraday. Every transformer humming away in an EV charger, solar inverter, or electricity substation today owes a debt to that Maynooth laboratory.

The Priest Who Shocked His Students (Literally)

Born on 22 December 1799 in Darver, between Drogheda and Dundalk, Callan was appointed to the chair of natural philosophy at Maynooth in 1826, where he taught mathematics, astronomy, and physics. He had a... let's call it "hands-on" approach to teaching.

To judge the power of his batteries, Callan persuaded his students to take electric shocks and gauged the strength by their reactions. With 14 cells, students felt the effect for days. With 16 cells, nobody could be persuaded to volunteer. One brave (or foolish) student, William Walsh, who later became Archbishop of Dublin, was reportedly knocked unconscious by one of Callan's shocks.

By 1848, Callan had assembled his monster battery: 577 individual cells using cast-iron casings and zinc plates. The entire contraption was reckoned to be the world's largest battery at the time. To demonstrate its power before a large college audience, he ran a current through a turkey. The bird was instantly electrocuted, a macabre but undeniably effective bit of showmanship.

Building Batteries Before Lithium-Ion

Callan didn't just build big batteries; he improved them. In 1854, he invented the "Maynooth battery," which used a cast-iron outer casing with zinc plates suspended inside, and in 1855 developed a single-fluid cell design that simplified construction. These weren't just academic exercises. Callan was solving real engineering problems about how to store and deliver electrical energy efficiently, the same challenge we're wrestling with today in home battery storage and grid-scale systems.

His giant electromagnet, built in 1836, could lift more than 1,000 kg when powered by his batteries. It was one of the most powerful electromagnets in the world at the time and demonstrated the practical applications of electrical engineering in an era when electricity was still considered something of a parlour trick.

The Induction Coil: Callan's Crowning Achievement

Callan's most important contribution was the induction coil, developed in 1836. The principle is elegant: wrap two coils of wire around an iron core, connect the primary coil to a battery, and interrupt the current rapidly. The collapsing magnetic field induces a much higher voltage in the secondary coil. It's the fundamental principle behind every transformer, voltage converter, and ignition coil ever made.

Callan also built early electric motors and dreamed big. He envisioned electrifying the Dublin to Dún Laoghaire railway line, decades before it actually happened. He understood that electricity, properly harnessed, could power transportation and industry, not just light up lecture halls.

From Maynooth to Modern Energy Storage

Nearly two centuries later, we're picking up where Callan left off, just with more efficient batteries and smarter electronics. At WattCharger, we design and install solutions for EV chargers, solar panels, and battery storage systems, helping homes and businesses generate, store, and move electricity efficiently and sustainably.

Callan didn't have lithium-ion cells, smart inverters, or renewable energy targets. But he had the same instinct: that electricity, properly understood and harnessed, could genuinely serve people. His induction coil made high-voltage electricity practical and portable. His batteries pushed the boundaries of energy storage. His electromagnets demonstrated the physical power of electrical engineering.

So next time you plug in your EV, watch your solar inverter quietly converting DC to AC, or check your home battery topping up overnight, spare a thought for the priest in Maynooth who was electrocuting turkeys in the name of science, and helped switch on Ireland's electric future.

Coming Next: Part 2: The Irish scientist who proved a shape and helped power modern solar panels.

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From solar panels to battery storage and EV chargers, WattCharger helps Irish homes and businesses harness electricity the way Fr. Callan envisioned: efficiently, sustainably, and in service of real people. Get your free consultation today.