Cabin Preconditioning
Cabin preconditioning heats, cools, ventilates, or clears the passenger compartment before departure while the vehicle is parked. Depending on the vehicle and conditions, it can prepare the air temperature, seats, steering wheel, windows, or windshield before occupants enter.
Cabin and battery are different targets
Cabin preconditioning is primarily for comfort and visibility. Battery Preconditioning brings the traction battery toward a suitable temperature for charging, power, regeneration, or efficiency. A vehicle may schedule both functions together and may use shared thermal hardware, but starting one does not prove that the other is active.
Energy while plugged in
On a vehicle that supports it, cabin preconditioning while connected can draw some or all of its immediate energy through the charging connection instead of depleting the traction battery by the same amount. This changes the energy boundary: conditioning energy may appear as grid or charger consumption before departure rather than as battery energy used during the trip.
The result is vehicle- and situation-specific. Charging power, battery state, control strategy, target temperature, weather, and preconditioning duration can affect where the energy comes from and how much is used. Cabin preconditioning therefore does not guarantee a universal energy or range saving, even though it can improve comfort and may reduce the cabin-conditioning load after departure.
See Heating, Ventilation and Air Conditioning for the broader relationship among cabin climate, battery temperature, heat pumps, and resistance heating.