Submitted by Roger1 on Mon, 2019-11-25 09:22
If you live where the temperature drops below 10C/50F, you know regenerative braking becomes unreliable as the weather gets colder. You must drive your Tesla like an ICE vehicle using the brake pedal to stop. The reason is the cold battery cannot accept all the power produced by the motor(s) when they act as generator(s). The vehicle’s kinetic energy is converted to heat by the brakes and thrown away. A possible solution to this problem is placing a suitably sized resistive heating element in the liquid heating/cooling loop. Regenerated electricity that cannot be stored in the battery could be dumped into the heating element to warm the fluid which is used to heat the battery and the cabin. Electricity consumption to provide heat is a major power user in winter so recovering kinetic energy as heat makes sense.
Two benefits come from this proposal. Regenerative braking would function consistently regardless of the temperature and energy currently wasted through the brakes would be captured to provide heat.