How often does your Hybrid Battery Pack FAN turn on?

never heard it in the GEN II but now with this 2010 I am hearing it when A/C is on and temps outside have been 95 in Georgia . I thought I heard something , turned radio off then realized it was the fan from the rear battery compartment. I never heard it in my 2007 . Had the 2010 for 1 month . also discovered no more SKS turn off button too .

 

What you heard is the gas tank pressure test. Has nothing to do with the HV bat.

 

Mine comes on as needed to keep the battery at or below its temperature setpoint, whatever that may be. As far as hearing the fan, well, quite frankly - never.

 

50k miles on my 2007 and I have not heard the HV fan?

Cacti

 

Does the sound associated with that last well over a minute?

 

As you see my Prius is "09 and just turned over 16,500 on odometer.
Fan came on for the first time today, 97 degrees, started car and began to back out of parking space. I noticed it immediately, I thought it was a car to my right side making the sound, I got onto street drove a couple hundred feet and pulled into a parking lot, opened the back door and checked it out. It was that definite a fan sound. I always recirculate the air, so I don't know why this happened for the 1st time, after this long a time in the usual "hot Nashville" weather.
I just trust the car computer to know what it's doing.

:noidea:

 

about 2 or 3 minutes for me.

 

Haven't heard it this summer, but once during 20 degree weather this winter I heard it cycling on and off while waiting at a post office! So it's also to keep the battery warm, I presume!

 

This happen to me today. I went out in the garage and a fan was running in the back of the car. The car was sitting for a least 8 hours. The fan ran for 2-3 minutes.

I am going to assume it is the gas tank pressure test as adamace mentioned. How often should this happen?

 

We own two 2010 Prius and a friend owns one as well. It seems the battery fan loudness and the driving techniques coincide.
If I am driving, the fan seems to run a lot. We live in an area of many hills and i'm always on the brakes a little bit down these hills to add some recharging action to the battery.
The more energy going into/out of the battery, the more heat is built up, the more the fan runs.

I never get to drive my friends car, i'm only a passenger. On the same terrain, his fan is a lot quieter and runs at a slower speed. But he uses his brakes like he's in an ordinary car and doesn't worry about recharging. He's visiting from the flat lands/prairies and has never heard the fan before arriving on the west coast.

Both of our cars are the Canadian Tech Pkg (basically a Prius IV with advanced technology) and my friends is the Premium Pkg + solar sunroof (Prius III with sunroof). So there is a difference in the cars and level of tech/battery draining devices. 2 loud fans in the Tech pkg and a quiet one in the lower model, maybe this means something?

Seems like different driving styles and different terrain AND the options on your Prius might mean the difference between those of us who hear the fan... and those who don't.

 

Fairly often on this hot days with AC. I got sick of it so I disconnected it.

I'm kidding. About the second part, but I do hear it often. Normally a couple minutes for me too I'd guess.

 

Hottest summer on record here, never heard it. I thought for sure I would hear it when it was over 100 for several days. I even left off the AC to force it on and it never came on.

I would say its time to make a service apt.!

 

Well, I heard the fan for the first time yesterday (after 44K miles) on my 2007 Touring. I paid attention today and heard it again. We are having a heat wave here in Central IL so I assumed the reason of the fan was just to cool the battery.

I still think is weird that I have not heard the fan previously (specially after 44K miles). I wonder if people with newer prius can hear the fan?

 

Oh yeah...I can hear it on the 2010 Prius I bought a few weeks ago. I didn't know what it was at first -- I thought the back right window was open.

 

The fan intake is in the right back seat area, about elbow high. It runs now and then to cool the batteries. You can hear it if you turn off your a/c and radio and listen closely. It is not loud.

 

I always thought that was the vent to outside, mine hisses... now I know.

and knowing is half the battle.

 

I recently traded up my 2010 III (c4clunker) to the one I really wanted, the solar IV. I have to say, after 17K miles in the III, I never heard the battery cooling fan. Now, in the IV, I hear it all the time. Is it possible that in the III, the material seats absorb more of the sound, hence, I never heard it, and now with the leather, the sound is more obvious? Just curious. I told my son the other day, "man, that battery cooling fan seems to come on every time we get on the freeway". I thought it was road noise and he confirmed it was coming from the vent. Like I said, 1 year, 17K miles, and I never heard it on the III version. Prius IV, hear it all the time.

 

Cwayne, I just got my 2011 Prius IV with the same set up as you (solar roof, etc). I had a 2007 Gen II previously. In my 2007, I rarely ever heard the fan, even on the freeway. I've noticed on my new car that i hear the fan come on almost every time I am on the freeway, but when I exit and slow down, it pretty much turns off. Driving around town in slow speeds and the fan is off too (or so low I can't hear).

Wonder why it comes on high on the freeway only? Last gen rarely did. Pretty sure it must a new design or something because I only have 300 miles on it.

If anyone has any technical info, let us know! Thanks