So, food for thought. In a regular ICE car, if you were to leave for 6 mo, you would most likely come back to a dead battery and need to jump your car to restart it. Then you would drive it around for a few minutes so it would charge back. This has always been my experience, although I never left a car for 6mo. Most was ever 6 weeks, but often when my parents would take 2-3 mo trips we would have to ask the airport security guy to jump start our car in the lot. What I wonder is why not let the car go down to 0%? Then when you come back, charge it back up. There would be no worry about stress on the battery, using electricity, etc...