1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Suggested summer cabin temperature to maximize MPG and battery life?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by StephenFromCT, Jul 26, 2019.

  1. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,490
    14,095
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Exactly. Like a check valve. (y)
     
    fuzzy1 likes this.
  2. StephenFromCT

    StephenFromCT Junior Member

    Joined:
    Jul 17, 2019
    41
    11
    0
    Location:
    Connecticut
    Vehicle:
    2013 Prius
    Model:
    ----USA----
    I am still learning, and slightly confused by the term "flapper door".

    In the rear trunk of my 2011 Prius here are the "layers". First I can easily remove the rug with the rubber bottom. Then, I unlatch the two twist locks before removing the semi-rigid cover, with the hinge). Then I can remove the plastic storage tray, above the spare wheel, and the cover above the 12V battery. At this point I can see the orange plastic high voltage service plug.

    Now I believe I was wrong when I assumed the "flapper doors" were the two floppy parts on the left and ride sides of the topmost rug.

    I found a graphic showing that the 2001 Gen 1 Prius has a vent on the rear left side of the car which exhausts the air to the exterior after it passes over the high voltage battery. In the 2001 Prius the fan is between the battery and the vent, so the fan pulls (via negative pressue) the air over the battery. In the Gen 3 models the fan is between the air intake and the battery, and therefore the fan blows (via positive pressure) the air over the battery.

    I found a second image (located in the priuschat.com Gen 2 forum) which shows a different design for 2004 cars:

    Battery vent fan | PriusChat

    The figure has a label for a "hot air outlet" exhaust on the rear right side near the 12V battery, also venting to the exterior.

    And finally, for Gen 3 section I found the following post with an excellent photo of the vent (I assume after removal of the duct carrying air from the HV battery):

    Exide Battery Vent Elbow and Tube Install | PriusChat

    Now I appreciate that the air does not return to the cabin after passing over the battery.

    @jerrymildred and @fuzzy1, so that I am clear, when you use the name "flapper door" I assume you are referring to a "check valve" cover similar to the vents used in houses for clothes dryers and some bathrooms to vent moist air?

    Thanks to all.
     
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    correct, it is rubber, and the positive air pressure pushes it slightly open to escape, but it keeps moisture and varmints out
     
  4. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,490
    14,095
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Precisely. The dryer vent covers I've seen are usually multiple louvers, though, while what we have is just one lightweight door hinged at the top and closed by gravity.
     
  5. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Yes, that is the idea.

    Some air through the traction battery will still leak back into the cabin through the floor anyway, but not the bulk of it. For that reason, the 12V battery needs a vent tube to insure all its fumes (including some sulfuric acid droplets and sometimes other toxics) go outside.
     
    Raytheeagle and jerrymildred like this.
  6. CR94

    CR94 Senior Member

    Joined:
    Dec 2, 2014
    2,642
    1,133
    0
    Location:
    Northwestern S.C.
    Vehicle:
    2011 Prius
    Model:
    Two
    That air is free to return to the cabin or to exit the car through the flaps, or some mix of both, whichever is easier at the moment. You guys are making a simple situation seem complicated.