I believe it is true that a plugged in Tesla has the same effect on the 12V battery as a 900 mA float charger. As we know, this will result in the battery failing in about a year. The question is what will happen with a larger (4A or 8A) float charger on the battery? If this can prevent the discharge/recharge cycles then the battery should last much longer than a year. That is what we are assuming will happen but there is not data yet to show this is the case. If someone who has one of these chargers (Cottonwood maybe) wants to try this out I would be happy to loan him my data logger so we can see the results with a larger charger. I don't plan to put a float charger in my car until Tesla stops replacing batteries annually. I remember reading (in this thread or another) that Tesla is aware of this problem and is working on a fix. So this is just investigating the problem to understand it so when the fix comes out it can be evaluated.