September 18, 2025
Uses waste heat from the internal combustion engine (ICE).
Heating is essentially “free” since the engine already produces excess heat.
EVs don’t generate much waste heat, so they must create heat using:
Resistive heaters: Work like an electric space heater; effective but consume a lot of energy.
Heat pumps (in many modern EVs): Transfer heat from outside air into the cabin using refrigerant. Much more efficient than resistive heating but less effective in very cold climates.
As a result, heating the cabin draws power directly from the traction battery, reducing range in cold weather.
Works the same way as in gasoline cars, via an AC compressor and refrigerant cycle.
However, in EVs the compressor runs on battery power, not engine power.
Running the air conditioner at high output consumes significant energy, which can cut range during hot weather.
Cold weather: Cabin heating, battery thermal management, and reduced battery chemistry efficiency can lower range significantly.
Hot weather: Continuous AC use also reduces range, though usually less severely than extreme cold.
In summary:
Unlike ICE vehicles, EVs must use battery power for both heating and cooling. Heating is especially energy-intensive without waste engine heat, and both climate control systems draw directly from the traction battery, lowering driving range in extreme temperatures.
