I am just wondering what will happen if hybrid mode OFF, A/C is ON for a long period of time? or I have to turn ON the hybrid mode before I can turn ON the A/C? 1) will the engine start itself to recharge? 2) turn OFF the A/C automatically ? 3) Warning sound? but nothing will happen?
hybrid mode? there's normal, Eco, and EV mode... there's no "hybrid mode"... you can turn on the a/c whenever you want.
If you turn the A/C on high it may start the engine depending on current draw, State of Charge (SOC) for the HV battery, and a couple other factors. This is just one of the reasons that running the A/C system hard can cause lower mpg. You will not hurt the car regardless of which mode you put the car in. If the HV battery is drained te engine will turn on to recharge it. You don't have to worry about anything. To reduce the impact of A/C use on mpg check out this thread. http://priuschat.com/forums/gen-ii-prius-fuel-economy/97814-how-reduce-mpg-loss-because-c-use.html
If the car isn't turned on, AC won't run, or anything else! If you mean the car is turned on but the engine isn't running, like at a stop light or running on EV, the AC will run, draining the battery till it hits two bars and then the engine kicks on to recharge the battery.
Note that if it's like the Prius liftback it will run the engine for a minimal amount of time, keeping the battery at two bars. It knows that it's inefficient to run the engine when the car's not moving.
The Prius is there to provide my comfort and driving happiness. It does all that... engine kicks in to charge the battery if I happen to feel like reading my mail while parked at the post office in 80 degree heat... luvvit. Still a small carbon footprint and 61+ mpg. :rockon:
I think what is meant is turning on accessories and running the ac without turning on the engine. The prius is different than other cars and I would assume you could get a functioning ac without running your engine as it runs without a belt using an electric motor so if you can get functioning ac it could drain your battery quickly.