Leakage detection device and battery pack having the same

A leakage detection device includes at least one optical coupler, a voltage divider, an analog-to-digital converter and a processing unit. Wherein, the at least one optical coupler is adapted to output an electrical signal according to a leakage degree of a DC power supply. The electrical signal is divided by the voltage divider to be output to the analog-to-digital converter and converted into a digital signal. The processing is adapted to compare a digital value corresponding to the digital signal with a reference value and output a leak signal when a difference between the digital value and the reference value is greater than a predetermined difference. A battery pack includes a battery cell assembly, a switch element, and a control unit, wherein the control unit controls the switch element to switch off an electrical connection between the battery cell assembly and the load to block electric power to the load.