The functioning of a battery is modeled through a potential double well in which a force of physico-chemical origin acts on charges, causing the population on one side side to increase in relation to the other. The electrical potential thus created is the source of an electro motive force. External charge circulation makes this electro motive force to decrease by means of an adequate mechanism. Its value as a function of the amount of circulated charge is calculated, as well as the kinetics of recovering after briefly short-circuiting it.
