Methods of and apparatus for removing heat generated by cells of a battery pack. The methods and apparatus may employ one or more fan modules disposed between or next to cells of the battery pack, or one or more fans directly mounted to the battery pack or battery pack case housing the cells. Further, a motor controller isolation system operates to electrically isolate the motor controller of the electric vehicle when the battery pack is being charged. The motor controller isolation system may be integrated with the integrated battery pack and thermal and ventilation system. The integrated system, or integrated battery unit (IBU), is preferably manufactured in a manner that requires no, modifications to the electric vehicle in which the IBU is installed.

A thermal dissipation structure includes a housing, a thermal dissipation mechanism, and a seal member. The housing accommodates a heat-generating element. The thermal dissipation mechanism includes a thermal transfer part and a thermal dissipation part. The thermal transfer part is disposed inside the housing. The thermal transfer part is configured to transfer heat generated by the heat-generating element. The thermal dissipation part is disposed outside the housing. The seal member seals between the housing and the thermal dissipation mechanism.

In a forklift, a battery is arranged rearward from a cabin in the rear portion of a vehicle main body. A motor controller is arranged frontward from the battery. A traction motor and a material-handling motor are arranged frontward from a cooling fan. The cooling fan discharges a wind, flowing from the front to the rear of the vehicle main body, to the rear of the traction motor and the material-handling motor.