Playing around with a space heater and Hybrid Battery Intake/Fan

Discussion in 'Gen 3 Prius Technical Discussion' started by PacificCornhusker, Jan 22, 2025.

  1. PacificCornhusker

    PacificCornhusker Junior Member

    Joined:
    Jun 17, 2019
    6
    1
    0
    Location:
    Nebraska
    Vehicle:
    2012 Prius
    Model:
    Two
    The last couple days I've messed around with put the Prius into ACC-Mode and running a space heater directly pointing into the Hybrid-Batt fan-intake port.

    Through Hybrid Assistant, the "Auto" setting on the fan goes to "3" and seems to auto heat the battery even though the cabin temp is WELL below freezing.

    Intake temp is reading at ~83F, and battery started at ~12F. Looks like 30F now.

    Anybody know what the temp/why the computer wants to heat up the battery?

    Yesterday I kept it all running while turning on the car and I believe it shut off the intake fan, for 10-20 seconds, then turned it back on.

    Anybody know @ what temp the hybrid-battery-vent-intake-fan will kick off?

    This is all just to see, out of curiosity, etc.
     
    #1 PacificCornhusker, Jan 22, 2025
  2. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    11,685
    4,730
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Does Hybrid Assistant run the cooling fan in ACC mode? I thought it would only do that with the car in Ready mode?

    But basically in sub freezing temperatures the battery ECU is going to limit how much the hybrid battery is used because using this battery type in super cold temps can shorten its lifespan, same goes with Lithium, but sodium-Ion is fine. Most modern Lithium powered cars have a thermal management system because Lithium performs way better at the perfect temperature.

    Whereas temperature doesn't matter as much with OEM battery, though about 97' F is where you'll have the very best performance from your pack.
     
    #2 PriusCamper, Jan 22, 2025
  3. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,343
    4,140
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Love how sodium and lithium is brought into the post while the post is stock battery. Makes no difference nor affects OPs approach to heating.
     
    #3 Grit, Jan 22, 2025
    MAX2 likes this.
  4. PacificCornhusker

    PacificCornhusker Junior Member

    Joined:
    Jun 17, 2019
    6
    1
    0
    Location:
    Nebraska
    Vehicle:
    2012 Prius
    Model:
    Two
    Yeah. Admittedly, I was a little confused by this, as my hybrid-battery is 100% OEM, 2014. But I do appreciate all input!

    I will report that I did wait until the Hybrid-Battery Intake-Temp Gauge via Hybrid Assistant on an Android tablet (I run it full time), showed the Temp was ~60F, and it truly is a NOTICEABLE difference in acceleration-dynamics (and maybe even decceleration), than when the same Battery-Temp is reported ~5 or 10F.

    ~97F may indeed be the physically ideal temperature, but I assure that that hybrid-battery will surpass 105F (triggering the cooling fan) within 10 minutes of driving easily. So it might be anti-practical, and even anti-unpractical to heat it up to 97F :LOL:
     
    #4 PacificCornhusker, Jan 23, 2025
    Grit likes this.
  5. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,885
    3,626
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    A lot of - degrees there. That doesn't sound correct.
    -83 degrees? -60, -97????
    I can't believe it gets that cold in Nebraska.
     
    #5 ASRDogman, Jan 23, 2025
  6. PacificCornhusker

    PacificCornhusker Junior Member

    Joined:
    Jun 17, 2019
    6
    1
    0
    Location:
    Nebraska
    Vehicle:
    2012 Prius
    Model:
    Two
    Lol,

    - vs ~

    Are you looking at this page through your phone maybe?
     
    #6 PacificCornhusker, Jan 23, 2025
  7. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,885
    3,626
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    Nope, a phone is for talking photos.

    ...Intake temp is reading at ~83F, and battery started at ~12F. Looks like 30F now...
    ... the Temp was ~60F, and it truly...
    ...~97F may indeed be the physically ideal temperature...


     
    #7 ASRDogman, Jan 23, 2025
    Last edited: Jan 24, 2025
  8. Brian1954

    Brian1954 Senior Member

    Joined:
    Jan 31, 2021
    1,501
    579
    0
    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    FYI, the ~ symbol means "approximately" or "about" or "around". It is not a negative (-) symbol.

    So, ~83F means approximately 83F or about 83F or around 83F.
     
    #8 Brian1954, Jan 23, 2025
    Last edited: Jan 23, 2025
  9. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,343
    4,140
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    I’ve seen a couple of posts that said when you pull air hotter into the hv battery case air temp, condensation is developed inside the hv bat assembly and can cause rusting if the process is prolonged. Bussbars will eventually rust or corode and lead to high resistance
     
    #9 Grit, Jan 23, 2025
  10. MAX2

    MAX2 Active Member

    Joined:
    Aug 12, 2024
    807
    237
    48
    Location:
    Third planet from the Sun
    Vehicle:
    2007 Prius
    Model:
    N/A
    Absolutely right. Any cold object, when it gets into a warm environment, is covered with a light layer of frost or sweat. Directing a stream of warm air into a high-voltage battery that is frozen is a bad idea.
     
    #10 MAX2, Jan 24, 2025
    Mendel Leisk likes this.
  11. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    25,663
    16,763
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    How humid the air is (or isn't) does figure into that question.

    Bringing a cold battery into your warm house (which may even have a humidifier) is likely to frost it.

    If the cold battery is sitting in equally cold air, and then you heat that same air (which reduces its relative humidity, unless you introduce more moisture somehow), that might not be a concern.
     
    #11 ChapmanF, Jan 24, 2025
    CR94 likes this.
(You must log in or sign up to post here.)