Zamboni pile

Lore & Background

The Zamboni pile was invented by Giuseppe Zamboni in 1812. It is constructed from discs of silver foil, zinc foil, and paper, typically about 20 mm in diameter.

Alternative materials include silver paper (paper with a thin layer of zinc on one side) gilded on one side, or silver paper smeared with manganese dioxide and honey. These discs are assembled into stacks that may be several thousand discs thick. The stack is then either compressed in a glass tube with end caps or stacked between three glass rods with wooden end plates and insulated by dipping in molten sulfur or pitch.

The pile produces an electromotive force of approximately 0.8 V per element. By stacking many elements, Zamboni piles can achieve output potential differences in the kilovolt range, but the current output remains in the nanoampere range. The famous Oxford Electric Bell, which has been ringing continuously since 1840, is thought to be powered by a pair of Zamboni piles.

More modern versions of the Zamboni pile were manufactured as recently as the 1980s for providing the accelerating voltage in image intensifier tubes, particularly for military use. Today, such voltages are obtained from flyback converters powered by lithium ion batteries.

Reader's Guide

The Zamboni pile holds a unique place in battery history as an early electrostatic battery that demonstrated the feasibility of generating high voltages from a dry, solid-state design. Its construction from simple materials—foils and paper—allowed for easy assembly into stacks that could reach thousands of layers, producing kilovolt outputs while drawing only nanoamperes of current. This combination made it suitable for applications requiring sustained high voltage with minimal power drain, such as powering the Oxford Electric Bell, which has been ringing since 1840 and is believed to be driven by two Zamboni piles.

The pile's legacy extends into the 20th century, with modern versions manufactured into the 1980s for military image intensifier tubes, where they provided the accelerating voltage. However, advances in power electronics have since replaced them with flyback converters powered by lithium ion batteries. The Zamboni pile remains a notable example of early battery innovation, illustrating how simple electrochemical principles could yield long-lasting, high-voltage power sources.