> Of those listed, only the air-conditioner is a significant battery drain. On almost all cars the aircon compressor is driven by the engine, not an electric m

> Of those listed, only the air-conditioner is a significant battery drain. On almost all cars the aircon compressor is driven by the engine, not an electric motor, so the motor needs to be running to cool the air. The fan that blows the air through the vents is electric, but the air coming out will only be ambient temperature if the motor isn't running.