A method for detecting a minor short in a battery block comprising at least one cell, the method comprising: a first step of measuring a voltage of the battery block in a process of charging the battery unit; characterized by: a second step of measuring a voltage of the battery block in a process of discharging the battery block; and a third step (S204; S205) of detecting the minor short in the battery block based on measurement results from the first step and the second step; wherein the battery block forms at least a part of a battery pack comprising a plurality of cells; and wherein: the battery pack includes a plurality of blocks serially connected together; each of the blocks includes a number of cells among the plurality of cells which are serially connected together; the first step comprises measuring a voltage of each of at least two of the plurality of blocks in the charging process; the second step comprises measuring a voltage of the at least two of the plurality of blocks in the discharging process; the third step comprises a fourth step (S204, S205) of determining whether any of the cells of the at least two blocks has a minor short; and the fourth step (S204, S205) comprises determining that at least one of the cells of the at least two blocks has a minor short if a condition that a difference in voltage between the two blocks is greater than a first predetermined threshold value holds for a first predetermined period of time or more in the discharging process and if the condition does not hold for a second predetermined period of time or more in the charging process. a first step of measuring a voltage of the battery block in a process of charging the battery unit; characterized by: a second step of measuring a voltage of the battery block in a process of discharging the battery block; and a third step (S204; S205) of detecting the minor short in the battery block based on measurement results from the first step and the second step; wherein the battery block forms at least a part of a battery pack comprising a plurality of cells; and wherein: a second step of measuring a voltage of the battery block in a process of discharging the battery block; and a third step (S204; S205) of detecting the minor short in the battery block based on measurement results from the first step and the second step; the battery pack includes a plurality of blocks serially connected together; each of the blocks includes a number of cells among the plurality of cells which are serially connected together; the first step comprises measuring a voltage of each of at least two of the plurality of blocks in the charging process; the second step comprises measuring a voltage of the at least two of the plurality of blocks in the discharging process; the third step comprises a fourth step (S204, S205) of determining whether any of the cells of the at least two blocks has a minor short; and the fourth step (S204, S205) comprises determining that at least one of the cells of the at least two blocks has a minor short if a condition that a difference in voltage between the two blocks is greater than a first predetermined threshold value holds for a first predetermined period of time or more in the discharging process and if the condition does not hold for a second predetermined period of time or more in the charging process.