Tesla Motors Club
I believe I've read every post on cold weather driving, including and especially the great one by @Doug_G : Cold Weather Driving
My question is based on my personal experience and this statement made by @Doug_G : "The second thing you'll notice is that you have regenerative braking at about half power instead of zero. That's because your battery pack is a lot warmer."
Note that Doug_G mentions "half power". I agree with Doug_G as I've personally never experienced full/100% regenerative breaking or completely "normal" energy use even after preheating.
Why can't or why doesn't the preheating completely warm the battery sufficient to provide full regenerative braking and more importantly to allow reduced energy usage immediately when driving? I notice that even if/when I preheat for 20+ minutes (while plugged in & NOT using range mode), my Model X still limits regenerative breaking and uses abnormally high energy, presumably until the battery pack heats up even more. Only after driving for a while do the yellow marks on the energy usage chart (indicating the reduced regenerative breaking) then go away and I notice a significant drop in the energy usage for the same given speed & conditions that I may have been driving just a few minutes earlier.
My curiosity is based on the assumption that the battery pack does not need seem to need ANY additional heating when the ambient temperature is ~70 degrees F outside. When it's only 30-40F outside, it seems reasonable that a plugged-in vehicle could on its own get the battery up to at least 70F. Afterall, the battery gets to that level once we're driving for a bit, so why can't preheating while plugged in do the same?
I realize none of us may know the real answer, so some speculation is welcome as long as it's (please) not crazy talk. For example, I can guess that the battery pack "heater" can only raise the temperature to a max temperature that is less than 70F (independent of ambient air temp), and the rest MUST come from the heat of the motors, etc. That's purely speculation on my part that the battery pack heater just can't do enough on its own. Does anyone know better than I?
My question is based on my personal experience and this statement made by @Doug_G : "The second thing you'll notice is that you have regenerative braking at about half power instead of zero. That's because your battery pack is a lot warmer."
Note that Doug_G mentions "half power". I agree with Doug_G as I've personally never experienced full/100% regenerative breaking or completely "normal" energy use even after preheating.
Why can't or why doesn't the preheating completely warm the battery sufficient to provide full regenerative braking and more importantly to allow reduced energy usage immediately when driving? I notice that even if/when I preheat for 20+ minutes (while plugged in & NOT using range mode), my Model X still limits regenerative breaking and uses abnormally high energy, presumably until the battery pack heats up even more. Only after driving for a while do the yellow marks on the energy usage chart (indicating the reduced regenerative breaking) then go away and I notice a significant drop in the energy usage for the same given speed & conditions that I may have been driving just a few minutes earlier.
My curiosity is based on the assumption that the battery pack does not need seem to need ANY additional heating when the ambient temperature is ~70 degrees F outside. When it's only 30-40F outside, it seems reasonable that a plugged-in vehicle could on its own get the battery up to at least 70F. Afterall, the battery gets to that level once we're driving for a bit, so why can't preheating while plugged in do the same?
I realize none of us may know the real answer, so some speculation is welcome as long as it's (please) not crazy talk. For example, I can guess that the battery pack "heater" can only raise the temperature to a max temperature that is less than 70F (independent of ambient air temp), and the rest MUST come from the heat of the motors, etc. That's purely speculation on my part that the battery pack heater just can't do enough on its own. Does anyone know better than I?