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
I can't seem to find the exact thread referencing the battery cooling fan I was looking for but here are a couple of links to other threads on the subject. http://priuschat.com/forums/gen-ii-prius-main-forum/35866-battery-cooling-fan.html http://priuschat.com/forums/gen-ii-...g/37794-high-hv-battery-temp-cooling-fan.html They provide some insight. There is even a nice pretty picture from efusco in the second link. From what I remember reading somewhere I think there are 3 thermistors in the battery "box" that monitor temp and will activate the cooling fan when needed. I rarely here mine come on and off but my wife's 2007 Touring seems to cycle more often especially after long days sitting in the sun here in Carolina on a freshly paved parking lot at her office. I hope this helps. Chris
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.
I have only heard mine once, and that was after a pretty long descent where the battery SOC showed all 8 bars.
