Battery pack for a vehicle

A battery pack for a vehicle, the battery pack comprising:

• a plurality of battery modules, a first one of the battery modules being arranged in a first level from among a plurality of levels of the battery pack, a second one of the battery modules being arranged in a second level of the battery pack, the first level being below the second level in a vertical direction, each of the battery modules being in a housing having a cooling channel structure;
• and
• a liquid cooling circuit in thermal contact with the cooling channel structures of the housings of the first and second ones of the battery modules respectively in the first and second levels of the battery pack, the liquid cooling circuit comprising:
• an inlet in the first level of the battery pack and at a first side of the first one of the battery modules;
• an outlet in the first level of the battery pack and at a second side of the first one of the battery modules,
• a first connection tube vertically extending between the inlet and the housing of the second one of the battery modules in the second level of the battery pack;
• a second connection tube vertically extending between the housing of the second one of the battery modules and the outlet;
• and
• a bypass tube having an inlet opening at a highest point of the liquid cooling circuit in the vertical direction and an outlet opening within the liquid cooling circuit at a lower point of the liquid cooling circuit than the highest point of the liquid cooling circuit, the outlet opening of the bypass tube being between an end of the second connection tube in the first level of the battery pack and the outlet,
• wherein the highest point of the liquid cooling circuit is in the second level of the battery pack, and the lower point of the liquid cooling circuit is in the first level of the battery pack.