The cutoff signal output step S300 may be a step for outputting a cutoff signal for cutting off a path through which a current is charged in order to cut off an inflow of a charge current to the battery cells. According to the output of the cutoff signal, the path through which the charge current flows to the battery cells, namely, the inflow of the charge current may be cut off by the cutoff unit 140 as described with reference to FIG. 2. Accordingly, the current being charged to the battery cells may be cut off.

The second voltage measurement step S400 may be a step for measuring a voltage of at least one or more cells having been determined to be overvoltage in the first overvoltage determination step S200.

Like the first voltage measurement step S100, the second voltage measurement step S400 may also be performed by the voltage measurement unit 120.

In other words, when describing on the basis of a time when the second voltage measurement step S400 is performed, the second voltage measurement step S400 is a step for measuring again the voltage of at least one or more cells having been determined to be overvoltage from among the first measurement voltages having been measured in a previous period N, and a voltage value calculated at this point is referred to as a second measurement voltage value.

The second overvoltage determination step S500 may be a step for comparing the second measurement voltage value of the at least one or more cells, which is measured in the second voltage measurement step S400, with a prescribed second reference voltage value to determine whether the cell is overvoltage through a comparison result.