Upgrade Battery Pack Fan?

Turn up the radio.

SAMSUNG-SGH-I747 ? 2

 

Have you ever verified that the noise that you were hearing was actually the battery fan? The battery fan is actually very quiet. Every time that I thought the noise was the fan, I would stop the car, turn off the radio and then stop the AC vent fan. The noise would be gone.

The battery fan has six different speeds. The highest that I have ever seen on SGII is 4th speed. I could not hear the fan even with my ear up to the rear vent. I asked my wife, who has always been able to hear a pin drop, to listen and she said that if she put her ear up to the vent she could just faintly hear it.

I also hear noise from the right rear passenger area. My opinion is that when the battery fan runs, it vents to the 12V battery compartment in the right rear corner of the cargo area and then vents to the outside through a pleated rubber door to the inside of the right rear wheel well. The noise that I am hearing is, in my opinion, road noise from the battery vent to the outside.

Now, every time I hear a change in the road noise coming from the right rear passenger area I will glance down at the SGII and the battery fan would be running.

 

use ear plugs....

 

Maybe you should get it checked out. I've never heard ours. Maybe clogging with lint or other problem?

 

I agree. I have actually gotten out and reclosed all of the doors to make sure that a door was not fully closed !

 

jdcollins5; I was also quite curious about this noise and always ended up checking the doors and windows if they are properly shut. but looks like what you have suggested about the road noise from vent is the actual noise source. thanks

 

Or you could try ramming air into the vent with a mod like this.

There's another photo showing the rear window closed as he offers up a duct on the outside, but all other photos show the rear window open, so I have no idea it it should work.

Here is his explanation on page 2 of the article 東京～熊本1600km無給油チャレンジはかなりの忍耐が要りました | 由良拓也／今井優杏の「あなたの愛車教えてください！」
"Oh, yeah, and then I have a very geeky thing to the ventilation holes to cool the battery, attached to the inside of the rear door on the Prius. It directs the airflow there. I made it with the carbon ducted and inset in the rear window. This is also avoids scratching the outside of the car." (combination of google translate and some guesses.)
Though this would probably be noisier than the fan.

 

I like the idea of moving the vent, but not for the reasons above. It makes me nervous where it is positioned as my kids like to lean a pillow up against the car side while we travel. I ask them to be careful not to block the vent, but you never know.

The design in the newer V is much better where it draws cool air from under the rear seat. IMO, a place less likely to be blocked, probably has cooler inlet temperatures and less of a direct sound-path to passengers.

 

For the extreme hyper-milers this mod is a must.
The concept of the external forced battery cooling is great and ingenious.
But to implement this mod, the rear passenger window need to be modified or replaced with something like lexan.
I would replace the small triangular rear window to accomplish similar task with less intrusion to the passenger area.

 

The gen2 vents the traction pack out directly from it to the 12v then out of the car, the gen3 includes the spare tire in the re-circulation area, and it's a pretty good speaker, so any noise it makes or adds to is what you hear, a little sound deadening around the area helped me