To use the off peak rate I only charge at night between midnight and 6 am. As recommended by Tesla I keep it plugged in all the time. The so called vampire drain is kind of high so even though I keep it plugged in, the state of charge drops after the charging has finished. I watched the car and noticed the battery management is definitely active when the car is just sitting there without charging. Every once it a while it seems to turn on the heater or cooler for the battery or maybe just circulating the coolant. Each time it does that it gets the power from the grid (I can see hear the main switch and the UMC shows the power flow.) Despite that the state of charge drops over time. It's usually not a big concern until I noticed that if I don't use the car for two days or more it won't start the scheduled charging at night even though the state of charge has dropped noticeable. It seem that schedule charging triggers the charging process only once. It won't start again the following night! For example I had the schedule charge set to 76 %. It finished two nights ago. Now, two days later, the state of charge as dropped to 73 %. If I just let it sit, it would drop to 0 % in 25 days. All while it's plugged in. It's kind of odd that the scheduled charging only triggers the charging process once. Does normal charging do the same thing? Will it start charging again once the state of charge drops beyond a certain level?