I keep reading a lot about balancing the battery and many people here seem to know exactly where it is happening and how. Now I'm pretty much aware that when many cells are in a battery pack they they need to be as similar as possible or else the weakest cell will effectively determine the entire pack capacity. What I don't understand is how many people here are so confident in knowing what and when the Model S is balancing the batteries. I can't find any reference in the manual about it and I'm not aware of any official statement from Tesla about it. In several discussions here I see people commenting on range loss caused by imbalance followed by a more or less detailed recommendation on how to balance it again. I can't help but wonder where that confidence is coming from. Is there any official info from Tesla about it, or are people just making things up? All I could find is the battery tear down where the person found resistors that could possibly be used to "bleed off" charge from individual segments. These resistors are pretty small and can dissipate only a very small amount of power, though. Not enough to explain extended charge sessions at 2 or more kW that people comment on saying it would be balancing. There is no doubt that imbalance with the pack is an issue, but wouldn't it be much better to prevent it from getting out of balance instead of constantly trying to fix it? Tesla recommends to keep the car plugged in all the time, even when not charging. I do that and I noticed the Model S will often turn on the coolant pump and run it for a short time. It is using grid power but very little so it's not heating nor cooling the battery (there is also no fan running). What it does IMHO is ensuring the temperature among all cells is the same at all times. I think that is key to keep the battery in balance. If two cells are identical, there is no reason they will drift apart in capacity if used the exact same way. But we all know too well that temperature has a significant impact on cell efficiency. If two identical cells are charged or discharged the same way but have different temperatures, they will eventually drift apart in performance/capacity. By keeping them at the same temperature at any given time, even when just resting, they will stay the same.