Battery pack

A battery pack comprising:

• a plurality of battery cells;
• a first case body accommodating the battery cells;
• a second case body provided above the battery cells accommodated in the first case body and accommodating the battery cells;
• a first water jacket provided on a bottom portion of the first case body and configured to allow a refrigerant to flow therethrough to adjust a temperature of the battery cells accommodated in the first case body;
• and
• a second water jacket provided on a bottom portion of the second case body, communicating with the first water jacket, and configured to allow the refrigerant to flow therethrough to adjust a temperature of the battery cells accommodated in the second case body, wherein
• the second case body is provided with:
• an erect wall erected around the second water jacket and configured to receive the refrigerant leaking from the second water jacket;
• and
• a discharge portion configured to discharge the refrigerant leaking from the second water jacket to a specific position of the first case body.