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Will it damage the hybrid battery if I blow water mist into the ventilation duct?

Discussion in 'Gen 3 Prius Technical Discussion' started by Mathews, Apr 27, 2024.

  1. Tombukt2

    Tombukt2 Senior Member

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    By what most of these HV batteries are making 8 to 10 years so you were saying if they were kept 20° cooler overall they would last another 2 years maybe three all righty like I say keeping a much cooler than say 75 or 80° that's not even human body temperature but yes sounds good sounds like in a car with working AC that's AC is used like it's recommended for a Prius when does down air coming in is not the way to conserve fuel and keep your drag coefficient which this car when it was made was one of the lowest in the industry but not with the windows down those days are long gone It's cheaper to have the air on reasonable and the windows up when you're flogging down the road.
     
  2. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I've gotten into our car after it was parked in full sun for about an hour, driven off without AC (just windows cracked so we wouldn't expire), and monitored battery temp. Temp slowly dropped. After about 15 minutes I turned on AC, set to cool aggresively and continued to monitor battery temp, After a further 10 minutes or so, battery temp had dropped, a further 1~2C. My take-away: AC use to preserve battery is overrated.
     
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  3. bisco

    bisco cookie crumbler

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    too much heat will shorten battery life. toyota designs the system to get most cars past the warranty period.
    there are no studies of how much heat at what temps for how long will take how much off the batteries lifespan.
    if you're concerned, you can do something. most people aren't bothered
     
  4. Carall

    Carall Member

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    Has this already been proven? I mean when the cooling system of the hybrid battery is working properly.
    For several years now I have been observing how they are struggling with temperature. Temperature control modules are being made and sold, but when you tell them that without restoring the capacity in the battery, by regulating the temperature you will not be able to maintain this capacity and certainly will not restore it.
     
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    Much easier and cheaper just to install rain deflectors on the windows and then leave the front windows cracked about 1/2" during the summer. Interior temp will be 15-20 degrees lower than if windows are left up. Toyota isn't stupid. Let the car take care of itself, the cooling system works. If you're really concerned, just get an app like Hybrid Assistant that will let you manually put the battery fan at any speed desired.
     
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  6. douglasjre

    douglasjre Senior Member

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    I want pictures of said water mister apparatus.
     
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  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Relax. Grit likes to be shocked.

    (you'll get to know us all after a while)
     
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  8. Mathews

    Mathews New Member

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    I also think of attaching a water cooling device to the battery pack, what do you think?
     
  9. ChapmanF

    ChapmanF Senior Member

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    Wait, there's two of you now? Sharing one screen name?
     
  10. ASRDogman

    ASRDogman Senior Member

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    Why not just drive under water? It will be easier....
     
  11. ChapmanF

    ChapmanF Senior Member

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    Hurts MPG, even before adding the ballast needed to keep the car on the bottom.

    Also, in many waterways, visibility is poor.
     
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  12. douglasjre

    douglasjre Senior Member

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    He needs to make a hybrid boat out of it. Yeah that'll work
     
  13. PriusV17

    PriusV17 Active Member

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    Something to think about. Recycled Air vs Fresh Air.

    The Prius has a rear vent flap where cabin air exits through the back and passes through the HV battery modules. If you keep your cabin in Recycled especially with the AC running then less air exits the rear vent flaps. Less cool air would pass through the battery modules. Fresh Air function should allow more air to exit the rear vents. It's really more of passive cooling vs active cooling by using the Fresh Air function rather than Recycled.

    vent-prius.png
     
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  14. ASRDogman

    ASRDogman Senior Member

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    Air is drawn in through the fan intake, blown across the hybrid battery,
    then out the vent under the battery.
    I would not matter if the "recycle" was on or off. And the flap is not 100%
    closed, only about 90%, so you'll always get 10% of the outside air.
    After the A/C has run and has started to cool off the car, you can use recirculate.
    Because the outside air will be a lot cooler than the air inside the car.
    As the car cools down, the air inside the car will be cooler than the outside are and
    the A/C will not have to work at hard to keep the inside of the car cool. Thus allowing
    cooler air to be blown over the hybrid battery.

     
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  15. ChapmanF

    ChapmanF Senior Member

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    Sure it matters—if there is less air entering the cabin at the front, there is less exiting the cabin out the vent under the battery (to have any more exiting than entering would mean pulling a vacuum in the cabin). The flow through the battery is therefore reduced.

    But that needn't be any cause for worry. The gen 1 New Car Features manual explained that the battery ECU holds a veto over the recirc setting ("battery ECU forced fresh air mode", page 171). When the battery ECU wants more flow, it gets more flow.

    Although that was in the gen 1 NCF, I don't have any reason for thinking it isn't still true in later gens.
     
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  16. Carall

    Carall Member

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    I don’t see the point of interfering with the cooling system of a hybrid battery developed by Toyota, it works as it was designed, but when a Prius sits all day under the scorching sun, the battery cooling system cannot participate, and that’s where the problem lies.
    One day, after turning on my Prius, which sat under the scorching sun all day, I saw this picture. The temperature in the middle of the battery was over 135 degrees. The blower turned on immediately and turned off after 15 minutes, when the temperature dropped to 120 degrees.

    Screenshot_20240429-163050_Dr Prius-1.jpg
     
  17. Wonder

    Wonder Member

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    I added a little usb fan to the air duct with a couple of zip ties. Be aware that the door partially closes over the duct and can hit the fan if that door is used. The fan I'm using is quite cheap and noisy but is blowing for now. If you get a obdll module and get the Hybrid assistant app it has an on off option to control the fan while app is open. Have you cleaned your hybrid fan lately? That's my next project. It was 118°f today so I'm trying to keep my cooling systems healthy also.
     
  18. Wonder

    Wonder Member

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    If the warm air exits the car after battery then should my ac be set on fresh air rather then recirculating?
    Never mind, I continued reading.

    Ok so then what is the vent hole on the driver's boot area of the back seat for then? If the air exits the car after the battery and the intake vent is on the passenger side seat arm belt area? We're they trying to have this thing blocked with location? Why invest in such high tech computer driven system just to have a air vent system for easy fail like it is?
     
    #38 Wonder, Jul 7, 2024
    Last edited: Jul 7, 2024
  19. ChapmanF

    ChapmanF Senior Member

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    The post you quoted before asking your question contains the answer.

    You can use whatever setting you want. If you have selected recirculate and the battery wants more cooling, it will override your setting. You don't have to worry about it.
     
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  20. ChapmanF

    ChapmanF Senior Member

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    I think I have failed to grasp your question in all its fullness.