If you look at the back seat on the passenger's side, you will notice a vent toward the top of the seat between the main center section of that seat and the door. That vent is the air intake to the battery. Many of us think that the purpose of that is for cooling the battery. Well the reverse is true during the winter. As the vehicle warms up the cabin interior the vehicle is going to pull that warmer cabin air down into the battery compartment and as such the battery will be warmed by cabin air.

Now, in the summer the battery temperature control system relies on the cabin being cooled to a reasonable level so that there is air cooler than outside air to cool off the battery during that season.

So, the long and short of it is that your comfort in the car is also the battery's comfort level and as such you should "set it and forget it" with regard to your A/C. Do not hesitate to run the A/C in the winter and in the summer at a temp setpoint and let the car decide how to keep you comfortable.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)