Hybrid battery fan and air inlet

March 25

2009-2012 model (2011 specifically)
From research I have done, looks like the important hybrid Battery cooling fan is buried in front of the Battery pack and not accessable without removing the top row Battery section (!) And so draws it air in from under the car around the front bulkhead area. Is there a filter located there? And if so can it be checked/cleaned/renewed?
[The prius with battery and fan under rear seat is notorious for needing the fan to be cleaned out or kept clean]
Ive not had chance to get deeply underneath to look yet.

Hydrid Assistant app can be used to keep an eye on battery and fan inlet air temperature's.

April 5

This video (and some others) shows the fan and inlet duct eg at approx 19 minutes in this video.

Also (at the beginning of the video) shows some limited access to the back of the Battery, which might be useful if want to just inspect for dust in that area (and hoover out)

Still havent had chance to have a good look underneath mine to see where the fan inlet area is
(will update this post later)

April 5

2 fans in fact by the look of it ?

April 6

Well I've finally been able to crawl underneath it and have a good look round, and no sign of any Battery fan inlet.
I will review, and maybe post, the underside photos/videos' I took.

So still hoping someone here will know or can comment.

side-note: My ancient 2 ton Halfords trolly jack struggled to lift the front end (front left), and its heavier than I thought.
Might need a new jack !
It had no issue lifting the old 1992 Estima.

side-note2: 12 year old vehicle but looks like a 1 year old underneath, its in such good shape. Even the (expected) rust on the exhaust and the exhaust hangers isnt too bad.

April 6

At 2.2 tons I bet it did.

April 6

From the video, 4:56 is the air inlet, hoover all dust out you will be ok, I directed the middle rear air con to floor near hybrid Battery air inlet in hot day, you will get more Battery performance.

April 17

Just had a reply from the maker of one of the strip down video makers.
"The fan gets its air from under the dash. There isn't a filter but it can clog with fine dust."

May 1

Just for info, another older post here about the HV Battery fans (plural)

May 3

Just done a test with a smoke generator (smoking matches) while Battery fan is running after a trip. Can confirm the air is sucked in from the vent at the back of the Battery box between the front seats, ie from middle row passenger feet area.
Not sure where it is blown out from.

Should be able to pull off that rear cover and hoover out the inlet area.
Will comment on that when I get round to doing it

My Battery temerature (as seen in various apps) is normally 28-34C
But was at 40C on a recent long fast but gentle motorway trip, which seems a bit high to me.

May 3

Update/correction.
My Battery temperature (as seen in various apps) is normally 32-38C
But was at 40C on a recent long fast but gentle motorway trip, which seems a bit high to me.

And 42C is when it stops certain EV operations (from what Ive read. Luckily never hit it)
"EV mode is disabled"

https://youtu.be/AXkbbyJi5C8?t=40

May 3

Another good video (in Japanese) showing the fan assemblies and ducting.
Output seems to be low down along the sides

https://www.youtube.com/watch?v=LgKcEH2b3ZY

May 4

Output is low down along the sides that is then ducted backwards under the front seats, especially on the front passenger side.
Can see the big flat black ducting in the video above.

Photo of the end of the outlet under the front passenger seat in the first two photos below

I took the rear cover off to examine the inlet, at there was very little trapped dust/lint (much less than collects on my laptop).
Obviously cleaned and hoovered it as best as is possible including with a small flexible tube extension, but wasnt much there?
Unfortunately cant get access to the fans to check and clean them without a major stripdown.
Could potentially make a plastic cover to fit over the back that allows you to blow air in (large quantity, fast, maybe from hair drier), while the fans were on full, to potentially help clean out the system?).

To remove rear cover-
remove seat anchor point plastic covers (pull backwards)
lift up carpet (as bottom lip of the cover is below carpet level
prise open/off at top
pull back, will unclip itself 3/4 down the sides
the bottom retainer (can see the slot int the picture below, is free as no longer held by the seat anchor plastic cover)
disconnect wires
pull back and up a bit and remove

The white padding is more for noise/vibration damping?