TB cooling fan duty cycle

Sorry guys, if this has been answered in another thread. We are taking a long trip in the Prius, and all I have available is my Blackberry, so I can't do a thread search.

I'm sitting in the right rear passenger seat, near the traction battery intake. When I moved back here at our last driver switch, the previous passenger had been laying on top of the vent. So when I got back here, I noticed that there was a low flow of air flowing into the intake. So obviously the TB cooling fan was running to to cool the battery. .

After being back here for a while, I've noticed that the air flow has stopped. This leads me to believe that the cooling fan cycles on and off as needed. Or possibly it slows down?

Hey! As I was about ready to send this, I just noticed that the airflow has started again.

Thanks

 

Thanks for those links, Chris.

I'm wondering if the fan is actually "variable speed". I have pretty good hearing, but didn't even know that the fan was running until I put my hand over the intake vent. Then if I put my ear up to it, I could hear the fan.

In those two links, some members mentioned that they had never heard the sound before, or that it only happened occassionally. I'm guessing that what they actually heard was the fan going into a "high speed" mode, and had never heard the fan previously, because it had been running at lower speeds.


Thanks again.