Excessive Noise (wind) Battery Fan

not sure how this will help ya, we have an 2011 prius and we had it now for 6 weeks so far i cant say i even heard it ,just asked the wife and she hasnt noticed it either,

 

I too have had an 2011 Prius for 3 months and have never been aware that the fan is on, I'm sure it has been on but I've not noticed it. Good Luck!

 

I have seen a few people talk about this. Yesterday it was 96 here i drove about 5 miles. Then i parked the car and left it on with the ac running full blast. i got in the back seat and put my ear right up to the vent. I coundn't hear anything and couldn't feel any air flow with my hand. I let it sit long enough to drain the battery most of the way down. i have never heard the fan in my 41,000 miles with the car. I do keep it cool inside the car in hot weather around 70 degres.

 

I have a 2010 III. I have over 25K miles on it and have never, ever heard that fan. I'd bring it back to the dealer and if they're no help find another one or contact customer relations.
Good Luck,

 

I hear mine on occasion, usually when it's hot outside and in stop and go traffic.

 

The fan should only come on when the battery temp is high... but this can depend on a lot of factors... outside temperature, inside temperature (because air for the battery comes from the inside of the car) and how much the battery is being used, among others. Additionally, I believe it's a variable speed fan, so it may be slower (and quieter) at times and faster (and louder) at other times. Because there are so many variables it's hard to compare what other people are seeing... particularly when they're in different climates.

Now, what I would suggest doing is asking the dealer to test drive one of the 2011's on their lot... preferably during a hot day, so the fan is more likely to come on and see if the fan sounds the same as your fan. If it does, then it's likely that the noise is normal and you'll just need to live with it. If not, then take the service manager for a trip in both cars and get him to see the difference.

Also, one more point... I'm in Orlando where it tends to be reasonably warm I rarely (if ever) hear my battery fan on the way in to work after the car has been sitting in a reasonably cool garage all night. However, I usually hear it during much of my commute home, after the car has been sitting in the hot sun all day. For some reason I usually don't notice the fan until 10 or 15 minutes into the commute. I'm not sure if that's because the AC fan is running at higher speeds duiring the beginning of the commute and it covers the noise of the battery fan or if the fan doesn't start immediately for some reason. Perhaps enough air is naturally forced through the battery vent when the AC fan is on high that it doesn't need to run it's own fan.

OK... maybe two more points... I'm also a bit puzzled by your description of this as wind noise. When my vent fan is running it sounds more like a motor or a fan... not really what I would describe as wind noise. Maybe it's just a case of semantics, but if you're hearing more wind and less fan then maybe something is blocking the vent.

 

+1. This is what I am thinking... perhaps the duct tube is squished or something is stuck deep inside. I figure the dealer didn't even look at it.

Personally I would either take stuff apart myself and inspect it or I would sit at the dealer till they did and accompany them during the process.

 

From the different replys that you got, I would say there is a problem on your car, the fan or the computer that controls the fan operation. Stay on the dealer, or another and try monitoring the temp thru a small hole in the fan exhaust (one which you can later plug) It seems to me the temp should always be less than ambient when 90 degrees plus. This could be very important down the line as your HV battery could fail, big time . So fix it while it is in warranty. You do run the Air Conditioner, right? More important for cooling the HV Battery than the passengers !

 

I've noticed my battery fan recently and I didn't notice it when it was only like 60-80 degrees outside. Currently it's like 95 degrees outside. It's noticeable but I wouldn't call it excess. More like a white noise aka whirling noise when you step on the brake and the battery charges, or when car runs only on battery.

 

I have a 2011 Prius Two, and the fan comes on regularly and almost anytime the car is in motion more than 30mph... and turns off (or slows down, anyway) as the car comes to a stop. Seems to me it's just being proactive with the battery cooling.

 

I have 2, 2010 Prius, bought at the same time from same dealer. One is mine, one for my wife. My one , you hardly hear the fan. In her one, I hear the fan almost all the time and then I also hear a high pitched sound that sounds like the fan bearing
I plan on going to the dealer next week to get them to take a look.

 

Old thread bump. I've had my 2013 for about a month and never heard a sound from this vent, but starting today I hear it anytime the car is in motion. It was around 83 today, which isn't crazy hot, and it's still making the noise at night after it has cooled down considerably. It's very annoying.

 

Have you checked for clogging of the duct? Even on hotter days, mine runs so slowly it's barely audible at close range, even with everything else off and no outside background noise.

 

I had a 2011 Prius. I drove it 48,000 miles. The vent fan was very quiet in it. I think you need to have someone take a look at it. It should not be loud.

 

I'll check it tomorrow. This seems to directly correlate with the vehicle speed, which is odd for a fan. It sounds like the vent is open to the outside and it's definitely something that just started.

 

can you hear it when stopped? have someone sit in the back and give a listen while you drive.

 

Something not right. I've NEVER heard our hybrid battery fan. And this is knowing it IS running, even up to speed 4 (out of 5 or 6 I believe). If it is this fan, I wouldn't just get annoyed, I'd get alarmed, check it out.