-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
My first winter
- Thread starter Shelby16
- Start date
If you navigate to a supercharger as you drive, at some point the car will start heating the battery. It will depend on your distance to the SC and when the car thinks it needs to start heating to make it there at the right temp. If you have only one motor, it won't be able to do a good job since you're already using that motor for propulsion. If you have a dual motor, the front motor will start heating at ~3.5kW, except when it's needed for propulsion. The target battery temp will be close to 40C, much higher than what you need for full regen which is around 21C, or for the snowflake to disappear which is even lower than that. Said another way, supercharger preheat uses the same system as when you preheat the cabin, except it can't use engines that are moving the car, and it will try to warm it too much. If you want to do that, might as well just preheat the cabin.
It's important to note that the end goal should not be to get the battery into ideal operating temperatures, but rather to get the most energy efficiency out of your electricity. Running heaters (either cabin or utilizing the motors) is incredibly draining on your stored electricity. There's no way you come out ahead using heaters just to get the battery warmer and get back the snowflake range. There is very little negative impact to the battery when running it cold. The car will make sure you can't hurt it (primarily by nerfing regen, aka charging it too fast).
The best solution is to charge the battery right before you need it. Charging is something you need to do anyway, and as a side effect, it warms the battery. So if you schedule your charging before your drive, you have decent charge and a conditioned battery.
In my garage, which I keep around 45F in the winter, it takes about 1.5 hours for the heat from charging to dissipate, so your scheduling doesn't need to be exact.
The best solution is to charge the battery right before you need it. Charging is something you need to do anyway, and as a side effect, it warms the battery. So if you schedule your charging before your drive, you have decent charge and a conditioned battery.
In my garage, which I keep around 45F in the winter, it takes about 1.5 hours for the heat from charging to dissipate, so your scheduling doesn't need to be exact.
My concern was more that if I were to need more breaking than just coasting to a halt (never needed it, but experimented a bit to get a better feel for the car). The increased regen i.e. stronger breaking even when slowly coming off the accelerator was very unstable in comparison to equal breaking acceleration as provided by the "regular" breaks. I found no satisfactory transition from letting off the accelerator to regular controlled braking when on standard regen. In contrast, low regen always felt under control. Might have been just a bad experience on my part. On regular regen breaking, does the ABS system kick in on the front wheels while ESP controls the rear - or is it all ABS (obviously not an issue on AWD)? Just curiosity from someone who knows very little about cars! Thanks!
Main losses come from heating while driving, m3 loose alot of heat thru glass roof. Also battery itself needs to bebheated - this is why you lose charge even when you dont use a car.
