Well, I have to say it didn't realize that 11v was "dangerously" low. I also didn't realize that 12v systems dropped such high percentage points for such low decimel drop. Most mornings it was around 11.9-12v. Just the one morning that we had a visitor that has a bad back so we kept the trailer at 65 degrees. I don't see me going to a different type of heat. I am aware and have been for many years that the forced air type heat in an RV is super parasitic on the batteries but there is not room in this rig for a catalytic type heater and it's not my thought that we will be in weather colder that 20 degrees, at least not for any length of time. I will likely install two more 6v batteries to keep things happy. I just love posting a thread like this and getting all this great information!