Abstract: A portable tool with discontinuous operation equipped with a pneumatic motor and an element driven in motion intermittently by the motor by a kinematic chain. The portable tool includes a generator for generating electric energy out of the kinetic energy of the element in motion, and at least one supercapacitor capable of storing the electric energy produced by the generator, and at least one battery. The battery is charged by the supercapacitor when the generator no longer produces electric energy. In this way, the combined use of a supercapacitor and a battery enables power to be supplied for longer periods to accessories embedded in the tool or electrically connected to the tool. The tool recovers the maximum energy produced by the motions and stores it in an embedded battery so as to be able to use it at any time thereafter.