NOVELTY - The accumulator assembly comprises electrical energy accumulator elements stacked according to a stacking axis, connecting electrodes (18, 20), spacers (22, 24) arranged axially between the electrodes, tie bolts (54) extending axially through cavities of the connection electrodes and spacers, end flanges (50, 52) engaging with the tie bolts to axially clamp the electrodes and the spacers, resilient prestressing units engaging with the end flanges to exert axial resilient prestressing forces on the stacked connecting electrodes and spacers, and a clamp.    USE - The accumulator assembly is useful for a battery of an electric vehicle or a hybrid vehicle.    ADVANTAGE - The accumulator assembly can be economically and easily manufactured and reliably operated for long time without degrading its performance.    DETAILED DESCRIPTION - The accumulator assembly comprises electrical energy accumulator elements stacked according to a stacking axis, connecting electrodes (18, 20), spacers (22, 24) arranged axially between the electrodes, tie bolts (54) extending axially through cavities of the connection electrodes and spacers, end flanges (50, 52) engaging with the tie bolts to axially clamp the electrodes and the spacers, resilient prestressing units engaging with the end flanges to exert axial resilient prestressing forces on the stacked connecting electrodes and spacers, a clamp for fitting the tie bolts with connection electrodes and spacers, a unit for maintaining the accumulator elements in position, a unit for isolating the accumulator elements. The prestressing units are axially disposed between a head of the tie bolts and the end flanges, and comprise an annular wafer with axial elasticity. The spacers include electrical conductor spacers and insulator spacers. The accumulator elements have positive and negative connection electrodes along the stacking axis so that a positive electrode element of the accumulator element is axially disposed adjacent to the negative electrode of the adjacent accumulator element. The insulator and conductor spacers are arranged for connecting the accumulator elements in series. The insulator spacers comprise a base and an extension in contact with an outer envelope of the accumulator elements, and extend partially in projection with the connection electrodes and a side of the conductor spacers. The conductor spacers comprise a recess within which a connector is connected to an electronic cable. The tie bolts comprise a male part including a threaded fastener and a closing head, and a female part including a fitting portion inside of which the threaded fastener is screwed and a supporting head in contact against the end flanges. The isolation unit comprises an insulating strip to cover the opposed side of the accumulator elements.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an accumulator assembly.    Electrical battery elements (12)    Connecting electrodes (18, 20)    Spacers (22, 24)    End flanges (50, 52)    Tie bolts. (54)