In 1860, the Frenchman Gaston Planté (1834–1889) invented the first practical version of a rechargeable battery based on lead–acid chemistry—the most successful secondary battery of all ages. This article outlines Planté’s fundamental concepts that were decisive for later development of practical lead–acid batteries. The ‘pile secondaire’ was indeed ahead its time in that an appropriate appliance for charging the accumulator was not available. The industrial success came after the invention of the Gramme machine. In 1879, Planté obtained acceptance for his work by publishing a book entitled Recherches sur l’Electricité. He never protected his inventions by patents, and spent much of his fortune on assisting impoverished scientists.