I was reading some speculation today about how the preheating might actually be super efficient (i have no way to verify this though).
The car will most likely just divert the coolant from the motors to the batteries, mostly skipping the radiators. This allows them to preheat the battery without expending any extra energy to do so.
The car will most likely just divert the coolant from the motors to the batteries, mostly skipping the radiators. This allows them to preheat the battery without expending any extra energy to do so.