These cells are among the oldest, and they use an aqueous solution of alkaline hydroxide (NaOH, KOH) fixed in an asbestos matrix as electrolyte. Their operating temperature can reach up to 230 °C. Pure hydrogen is used as fuel and pure oxygen or carbon dioxide-free air as an oxidizing agent.

In these cells, various types of catalysts can be used, not just those based on platinum. Nickel, silver, their oxides or noble metals can be used. These cells have mainly found use in space or military applications.