An electric storage balancing circuit for an energy storage device which comprises a plurality of electric storage devices (B1 - B4) connected in series so as to provide positive and negative terminals (+B, -B) and arranged in at least first and second assembled electric storage devices, the circuit comprising: a first coil; a first switching unit configured to switch between energy accumulation from the whole energy storage device into the first coil and energy release from the first coil to any one of the electric storage devices (B1, B2) in the first assembled electric storage device; a second coil; a second switching unit configured to switch between energy accumulation from the whole energy storage device into the second coil and energy release from the second coil to any one of electric storage devices (B3, B4) in the second assembled electric storage device; characterized in that: the electric storage balancing circuit further comprises: a first current limiting circuit including a first comparator for comparing a voltage derived from current flowing through the first coil with a first reference voltage; a second current limiting circuit including a second comparator for comparing a voltage derived from current flowing through the second coil with a second reference voltage; in that the first switching unit and second switching unit switch responsive to the first comparator and to the second comparator, respectively; and in that the circuit further comprises: a reference voltage control unit configured to adjust one of the first and second reference voltages based on voltages associated with the first assembled electric storage device and the second assembled electric storage device, when energy is accumulated in the first coil and the second coil, to change the current on the first and/or second coil. a first coil; a first switching unit configured to switch between energy accumulation from the whole energy storage device into the first coil and energy release from the first coil to any one of the electric storage devices (B1, B2) in the first assembled electric storage device; a second coil; a second switching unit configured to switch between energy accumulation from the whole energy storage device into the second coil and energy release from the second coil to any one of electric storage devices (B3, B4) in the second assembled electric storage device; the electric storage balancing circuit further comprises: a first current limiting circuit including a first comparator for comparing a voltage derived from current flowing through the first coil with a first reference voltage; a second current limiting circuit including a second comparator for comparing a voltage derived from current flowing through the second coil with a second reference voltage; in that the first switching unit and second switching unit switch responsive to the first comparator and to the second comparator, respectively; a first current limiting circuit including a first comparator for comparing a voltage derived from current flowing through the first coil with a first reference voltage; a second current limiting circuit including a second comparator for comparing a voltage derived from current flowing through the second coil with a second reference voltage; in that the first switching unit and second switching unit switch responsive to the first comparator and to the second comparator, respectively; and in that the circuit further comprises: a reference voltage control unit configured to adjust one of the first and second reference voltages based on voltages associated with the first assembled electric storage device and the second assembled electric storage device, when energy is accumulated in the first coil and the second coil, to change the current on the first and/or second coil.