Computerdoctor wrote:Well, as a matter of fact I DO have some kind of battery heating. At least that´s what I have figured out since I have a 2012 for the "cold" markets. Or is this just another misconception of mine...?
Read somewhere that it will heat the battery from -4 F to 14 F whenever needed. I figure that once I start driving the chemical process itself will warm the batteries?
This leads me to another thought of mine : Is it possible to (generally) store more power in cold batteries than hot? That the electrons will be more compact stored in the battery but on the other hand they will move slower and therefore give less power? Then when the battery is used it heats up and releases more of the stored energy?
As others have said, the battery heater is to protect it from damage in very cold weather. Be aware, however, that the battery heater won't work unless there is more than 30% charge in the battery or the car is plugged-in. From the manual:
The Li-ion battery heater does not operate if the available Li-ion battery charge is less than approximately 30% and the charger is not connected to the vehicle. To help prevent the Li-ion battery from freezing, do not leave the vehicle in an environment if temperatures may go below -4ºF (-20ºC) unless the vehicle is connected to a charger.
So, if you expect your car to get to -20ºC it is best to be sure it is plugged-in. (For what it is worth, the battery heater draws 300 Watts, but it runs only as needed, so it isn't a continuous 300 W draw.)
Your range in winter will be improved if you can keep the car in a garage that stays warmer than outdoor nighttime temperatures. Another thing that will help cold weather range is to pre-heat the car while plugged-in (by using the Climate Control timer or by turning it on remotely or manually) before leaving home. Then you might be able to get by on cold weather days using just the steering wheel and seat heaters, which take very little power, rather than the power-hog cabin heater. Of course, whether or not this is practical depends on how long the trip and how cold it is. Around 0ºC it works well. At -15ºC the cabin would probably cool down too much to be comfortable. And if parked outside all day in very cold temperatures with no plug available, using the cabin heater will be necessary.
A lot of this depends on how far you have to drive each day. If you aren't close to stretching the range, say 50 km a day, run the heater and don't worry about it. Just be aware that pre-heating can help a lot if cold weather range is a problem. And it also is very nice to get into a warm car in winter! How long you will need to pre-heat depends on the car temperature and is something that you will need to experiment with. Also, the temperature for pre-heating is set to 25ºC and can't be adjusted.