本发明揭示一种电池组的压降设备与方法。此设备包括有：一放电电阻，连接于该电池组中复数个电池其中一目标放电电池，并且使该目标放电电池之电压下降；一开关区块，连接于该目标放电电池、与该放电电阻；一电压量测区块，用来量测目标放电电池之电压；以及一控制区块，系根据该电池所测量到之电压值来控制该开关区块，以维持该放电电阻所消耗之能量固定不变。此方法之步骤包括：量测一电池组之复数个电池中之一目标放电电池的一电压；利用量测得到之该电压之数值与一放电电阻之数值，计算一连接于该目标放电电池、与该放电电阻之开关区块之一脉宽调制功率；以及根据该功率控制该开关区块，以维持该放电电阻所消耗之能量固定不变。

Disclosed are apparatus and method for discharging a voltage in a battery pack. The apparatus comprises a discharge resistance connected to a discharge target battery of plural batteries in the battery pack and discharging a voltage of the discharge target battery; a switching section for connecting the discharge target battery and the discharge resistance; a voltage measuring section for measuring a voltage of the discharge target battery; and a control section for controlling the switching section depending on the measured voltage value of the battery so as to maintain an energy consumed in the discharge resistance to be constant. The method comprises measuring a voltage of a discharge target battery of plural batteries in the battery pack; calculating a PWM duty rate of a switching section connecting the discharge target battery and a discharge resistance using the measured voltage value and a value of the discharge resistance; and controlling the switching section depending on the duty rate to maintain an energy consumed in the discharge resistance to be constant.