Battery pack and its control method

A battery pack comprising:

• a housing having
• a first side facing a front direction,
• a second side positioned opposite the first side,
• a third side positioned adjacent to both the first side and the second side,
• a fourth side positioned opposite the third side,
• an air inlet disposed on the first side, and
• an air outlet disposed on the second side;
• a plurality of battery cells;
• a fan positioned within the housing;
• a temperature sensor configured to sense a temperature;
• and
• an electronic controller configured to:
• receive a signal from the temperature sensor,
• determine, based on the signal, the temperature,
• determine whether the temperature is greater than a first temperature threshold, and
• turn on the fan for a first speed to move air from the air inlet to the air outlet in response to determining that the temperature is greater than the first temperature threshold.