An oscillatory mass operative to drive the rotor of a current generator adapted to charge a capacitor feeding the clockwork of an electronic watch is situated above the dial of the watch, which dial serves as a supporting plate for this mass. The arm of the mass is articulated at the center of the clockwork by means of a ball-bearing carried by the plate constituting the dial. The hours division is of relatively small diameter, leaving free the annular part of the dial opposite which the peripheral portion of the mass moves. The dial serves at the same time as a supporting member for the outer journal ring of a ball-bearing supporting the oscillatory mass and is secured to the frame of the clockwork by means of screws. The outer journal ring of the ball-bearing supporting the mass is rigid with a pinion meshing with a pinion of gearing coupled to the rotor of an electric generator driven by the said mass.