Thanks VietVet'67, that link drives home what I was trying to say. The auxillary air conditioning cools the battery, but the 2nd coolant resevoir has nothing to do with that. The cooling system and the air conditioning are two totally different systems. The 2nd coolant jug is for the eCVT. I just read your post on the other link. I need to explain that the ICE runs the A/C compressor. There is no cooling going on without the ICE on, for the front passenger compartment or the rear battery cooling system. So it can only use A/C to cool the battery when the ICE is on. It can however, open the outside vent and turn on the fan without ICE on, but the air is not going to be cool. I hope this helps. On a different note, I'm up to 28.0 mpg now! Woo Hoo!