ENERGY TRANSFER CIRCUIT, AND ELECTRICITY STORAGE SYSTEM

Cell selection circuit (11) is provided between n cells (C1 to C4) connected in series, where n is an integer of 2 or more, and inductor (L1), and is provided at both ends of the selected cell and both ends of inductor (L1) can be conductive. Clamp circuit (12) includes at least one clamp switch (Scl to Sc4) for forming a closed loop including inductor (L1) in a state where cell selection circuit (11) does not select any cells (C1 to C4). Current detection circuit (Rs, AP1) detects the value of the current flowing through inductor (L1). Low-pass filter (15) band-limits the detection value. Overcurrent detection circuit (16) activates the protection of inductor (L1) when the band-limited detection value exceeds the threshold.