Circuit/System Description
The drive motor generator battery is cooled by a drive motor battery vent fan motor. The battery vent fan motor and battery vent fan relay are located inside the drive motor generator battery assembly. B+ to the battery vent fan is provided from the battery vent fan relay when the drive motor generator battery control module (BECM) supplies a ground to the battery vent fan relay. A ground wire from the battery vent fan motor assembly completes the path to case ground. A 5 V circuit is provided from the battery vent fan motor assembly, to the drive motor generator battery control module. The drive motor generator battery control module uses a pulse width modulated (PWM) signal on the 5 V circuit to control the battery vent fan motor duty cycle. The drive motor generator battery control module uses 4 battery temperature sensors, one air inlet duct and one air outlet temperature sensor to control battery vent fan motor operation and speed.