A method for controlling the state of charge (SoC) of an electrical energy accumulator, especially a battery, of a hybrid vehicle which has an internal combustion engine and an electric machine, wherein the battery is operated in a working state-of-charge range (30%, 80%) which lies completely within the theoretically possible state-of-charge range (0%, 100%) of the battery, characterised in that the battery, in - a first sub-range (1. TB) of the working state-of-charge range is charged by the electric machine, the electric machine operating as a generator and being driven by the internal combustion engine, the first sub-range (1. TB) of the working state-of-charge range being defined by the lower limit (30%) and a first sub-range limit, - a second sub-range (2. TB) of the working state-of-charge range is neither charged nor discharged, the electric machine operating as a generator and being driven by the internal combustion engine and in so doing supplying current merely to a vehicle electrical system of the hybrid vehicle, the second sub-range (2. TB) of the working state-of-charge range being defined by the first sub-range limit and a second sub-range limit, - a third sub-range (3. TB) of the working state-of-charge range is discharged and in so doing supplies current to the vehicle electrical system, with the electric machine running along passively in such a way that the electric machine neither receives electric power nor delivers electric power, the third sub-range (3. TB) of the working state-of-charge range being defined by the second sub-range limit and a third sub-range limit, and in - a fourth sub-range (4. TB) of the working state-of-charge range is discharged and in so doing supplies current to the electric machine, which is operating as an electric motor, the fourth sub-range (4. TB) of the working state-of-charge range being defined by the third sub-range limit and the upper limit of the working state-of-charge range. - a first sub-range (1. TB) of the working state-of-charge range is charged by the electric machine, the electric machine operating as a generator and being driven by the internal combustion engine, the first sub-range (1. TB) of the working state-of-charge range being defined by the lower limit (30%) and a first sub-range limit, - a second sub-range (2. TB) of the working state-of-charge range is neither charged nor discharged, the electric machine operating as a generator and being driven by the internal combustion engine and in so doing supplying current merely to a vehicle electrical system of the hybrid vehicle, the second sub-range (2. TB) of the working state-of-charge range being defined by the first sub-range limit and a second sub-range limit, - a third sub-range (3. TB) of the working state-of-charge range is discharged and in so doing supplies current to the vehicle electrical system, with the electric machine running along passively in such a way that the electric machine neither receives electric power nor delivers electric power, the third sub-range (3. TB) of the working state-of-charge range being defined by the second sub-range limit and a third sub-range limit, and in - a fourth sub-range (4. TB) of the working state-of-charge range is discharged and in so doing supplies current to the electric machine, which is operating as an electric motor, the fourth sub-range (4. TB) of the working state-of-charge range being defined by the third sub-range limit and the upper limit of the working state-of-charge range.