While navigating to the supercharger is how you trigger the automatic preheating, I have found that depending upon the ambient temp and how long the battery was parked (depth of cold soak), and driving conditions, it still can take between 1-2 hours of normal driving prior to reaching the supercharger to achieve maximum charge rates. There is quite a large mass of the battery pack that you are needing to get uniformly warmed up which can take some time.