A hearing instrument system (1, 2, 3, 4, 5, 6), comprising: - a hearing instrument (12, 22, 32, 42, 52, 62), said hearing instrument (12, 22, 32, 42, 52, 62) having an energy transfer interface and a communication interface; - an accumulator system (11, 21, 31, 41, 51, 61), said accumulator system (11, 21, 31, 41, 51, 61) having an accumulator (13, 23, 33, 43, 53, 63), an energy transfer interface, a communication interface and an accumulator control facility (14, 24, 34, 44, 54, 64); - and a charging system (10, 20, 30, 40, 50, 60), said charging system (10, 20, 30, 40, 50, 60) having an energy transfer interface, a communication interface and a charge control facility (15, 25, 35, 45, 55, 65); wherein the accumulator-side energy transfer interface and communication interface can set up a respective energy transfer link or communication link to the charger-side and hearing-instrument-side energy transfer interfaces and communication interfaces, wherein said accumulator system (11, 21, 31, 41, 51, 61) uses the relevant energy transfer link to make energy stored in said accumulator (13, 23, 33, 43, 53, 63) available to said hearing instrument (12, 22, 32, 42, 52, 62), wherein said accumulator system (11, 21, 31, 41, 51, 61) transfers an item of information relating to the accumulator (13, 23, 33, 43, 53, 63) and generated by said accumulator control facility (14, 24, 34, 44, 54, 64) to said hearing instrument (12, 22, 32, 42, 52, 62) and/or said charging system (10, 20, 30, 40, 50, 60) by way of the respective said communication link; and said accumulator system (11, 21, 31, 41, 51, 61) transfers an item of state of charge information dependent on the state of charge of said accumulator (13, 23, 33, 43, 53, 63) and determined by said accumulator control facility (14, 24, 34, 44, 54, 64) to said hearing instrument (12, 22, 32, 42, 52, 62); wherein said energy transfer link between said accumulator system (11, 21, 31, 41, 51, 61) and said hearing instrument (12, 22, 32, 42, 52, 62) is also embodied as a communication link; wherein said accumulator system (11, 21, 31, 41, 51, 61) provides a regulated supply voltage for said hearing instrument (12, 22, 32, 42, 52, 62) by way of the energy transfer and communication link and said accumulator system (11, 21, 31, 41, 51, 61) transmits the state of charge information by setting the supply voltage to a predetermined value. - a hearing instrument (12, 22, 32, 42, 52, 62), said hearing instrument (12, 22, 32, 42, 52, 62) having an energy transfer interface and a communication interface; - an accumulator system (11, 21, 31, 41, 51, 61), said accumulator system (11, 21, 31, 41, 51, 61) having an accumulator (13, 23, 33, 43, 53, 63), an energy transfer interface, a communication interface and an accumulator control facility (14, 24, 34, 44, 54, 64); - and a charging system (10, 20, 30, 40, 50, 60), said charging system (10, 20, 30, 40, 50, 60) having an energy transfer interface, a communication interface and a charge control facility (15, 25, 35, 45, 55, 65); wherein the accumulator-side energy transfer interface and communication interface can set up a respective energy transfer link or communication link to the charger-side and hearing-instrument-side energy transfer interfaces and communication interfaces,