HV Battery Cooling Fan

No filter in the Gen2.
So you have to inspect the fan which requires a bit of DIY auto work (some posts show how to).
So to tell you the truth at 170k miles and going on 12 years I have not inspected it.
Dogs and lots of back seat activity are debris causing factors, which means I should probably check as we've had the grandkids back there last few 4 or 5 years.

 

Wow WJ with all the talk on this site about cleaning the fan too..lol...

But it is a pain in the tookus.

 

After cleaning you might want to consider making a filter to fit behind the intake vent on the back seat. I use something like this from Home Depot.

Frost King 15 in. x 24 in. x 1/4 in. Foam Room A/C FPR 2 Air Filter-F1524 - The Home Depot

It's big enough to cut multiple filters and is very good at catching hair and dust while not restricting air flow. Well worth the major investment of $2.

 

I did the same but just attached it to the outside of the filter with double sided tape and it sticks on that good. I Just cut a square of filter media out a little bigger than the vent enough to rim the vent with double sided tape. Easily serviced.

 

Yours is a touch simpler. I like mine because it's out of sight and I have kids in the back seat often. I pre-cut a bunch and have them in a drawer in the garage. I just pop the plastic cover off and slide a new one on every three months when I use the Prolong HV charger.

 

yes I can see that with kids. Good one.

 

Be sure to secure your filter if it sits on the inside. This happened and had to fully take out the fan to get it and did a cleaning while I was at it.

Go with this other filter that JC from this forum reccomebds.

 

I have 2009 Prius touring 141,000miles. I have a dog but do not let him in our Prius. However, upon inspection it looks like the loose hair that is on my clothing is enough to get in there. The entire project took 2 hours from start to finish. I feel this is good being that this was my first attempt. Just make sure you invest in a paneling removal tool. It will save you a lot of headaches. In fact, this was probably the most difficult thing about the project. Just making sure you keep track of all the screws and fasteners and making sure you do not break them. As you can see this is about 10 years of accumulation. It wasn’t that bad. I am hoping that my 3 battery temp sensors will now read temps in the lower 100’s on a 90 degree day rather than the 122degree readings I was getting. I suggest everyone do this at least once or twice in the cars lifetime if you do not let pets in your car and at least every 3-6 months if you do let pets into your car. The more the merrier. Keeping the battery cool and dust free should be your goal every day with these cars.

Tools needed for job:

1. 10mm socket w/extension
2. Panel removal tool
3. Air compressor or a can of compressed air (to clean the fan)
4. Small thin flat head screw driver (for push fasteners)

Make sure you do not over spin the fan with compressed air. I heard that it could damage the motor. I am not sure how accurate that info is but better safe than sorry. I was thinking about using a liquid to make it look like new but didn’t want to chance it. As long as the blades do not have significant accumulation on them and are able to move larger volumes of air it should be fine in my opinion. While I was back there I vacuumed the spare tire well, wiped down and disinfected everything. I also wiped out the plastic duct work as much as I could. My mind can rest easy now.

 

welcome and well done!

 

-Update-
​

As you can see from Post #10 I cleaned the hybrid battery cooling fan for the first time since I owned the vehicle. I am not sure if it was serviced prior to now but I have had fantastic results.

Prior to the cleaning my 3 temperature sensors were reading:

• TS-1 : 99-110 degrees
• TS-2 : 110-123 degrees
• TS-3 : 99-110 degrees
• Outside ambient temperature: 90 degrees
• A/C : set at max

After the cleaning and sanitizing of the whole area:

• TS-1 : 90-99 degrees
• TS-2 : 98-113 degrees
• TS-3 : 90-99 degrees
• Outside ambient air temperature: 92 degrees
• A/C : set at max

Moral of the story is to clean your hybrid battery fan if you wish to keep your vehicle on top shape. No matter if you think it is clean or not. The light amount of buildup that was inside the fan was raising the temp around 10 degrees. That is enough to degrade your packs quicker. The variation in all the recorded temperatures corresponds directly to the level of charge in the pack.

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if you really want to keep the battery cool extend the rear fabric package cover and put a silver insulated board on top of that. There sold as 4x8 sheets at Lowe’s. Cut down to fit perfectly on the fabric cover.

It really keeps the area cool above the battery and never ever let the car sit in the sun without a weather tech insulated custom fit windshield sunshade. They are the best. Hot cabin will roast the battery.

Cover is sold here at the Priushop. Going on my 11th year with mine.

 

I've heard that you have to clear the OBD codes related to the fan before cleaning the filter and reinstalling it, or else you can damage your fan. Is this a bunch of hogwash?

 

That is very surprising given the small amount of fuzz on those fan blades. A mm or two stuck to the blades usually makes no difference at all in fan performance (for basically any macroscopic fan) because the boundary layer of air just above the blade surface is barely moving even on a clean blade. The cynic in me wonders if there wasn't some other variable involved in your measurements, for instance, a difference in the the amount of sun exposure.

In any case, good job for cleaning it out because for all you knew it could have been quite thoroughly stuffed up. (Cleaned our DVR last month and found the top of the heat sink to be completely solid with dust under the CPU fan.)

 

hogwash