Is cabin heat "free" if a Prime is in HV mode?

Discussion in 'Gen 5 Prius Main Forum' started by Will B, Mar 24, 2026.

  1. VelvetFoot

    VelvetFoot Active Member

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    What's the magic number where the car won't start? Getting close?
     
  2. mva

    mva Member

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    where did you get that number from?!!!

    It reminds me of all the paranoia I experienced, years ago when I purchased my Gen 2 Prius. We have all seen how that ended with very long battery life and pretty inexpensive replacement. And the gen 5 battery looks very serviceable, something I would probably tackle myself, other than recharging the refrigerant.
     
  3. Paul Gregory

    Paul Gregory Senior Member

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    I've never seen it. -42C didn't prevent me from starting, and I never use an engine heater.
     
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  4. Gokhan

    Gokhan Senior Member

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    The entire traction battery needs replacing if there's a refrigerant leak. OK, maybe around $10,000 instead of $20,000. LOL

    Hybrid system Malfunction (Visit Your Dealership) | Page 4 | PriusChat
     
  5. PriusCamper

    PriusCamper Senior Member

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    It's important to remember that this isn't Toyota being honest about what's possible for repairs, just that they are trying to convince everyone that all the AC components and HV battery components are integrated and have to be replaced as a single unit.

    Truth is Toyota said the same BS about repairing hybrid batteries when a cell goes bad, but a quarter century later there's hundreds of successful businesses doing just that, most notable GreenBean/LKQ, GreenTec, Hybrid2Go, PriusKings...

    As in Toyota is more interested in defrauding their customer with outrageous repair prices than telling the truth about how to fix something in an affordable way. This is one day going to blowback on them in spectacular ways. You can only rip people off for so long before they lawyer up and start fighting back!
     
    #45 PriusCamper, Apr 1, 2026 at 4:36 PM
    Last edited: Apr 1, 2026 at 4:44 PM
  6. BiomedO1

    BiomedO1 Senior Member

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    To be fair; Toyota doesn't overhaul motors or transmissions either. They are assembly/parts replacement jockeys. It takes a lot of time and equipment to "properly" repair a traction pack. So at $200+/hr recharge rate; it's cheaper to replace the entire pack, than to fuss with it.
    You also failed to mention the amount of come-back/warranty repair and high failure rates of those "slapped together" packs. Don't take my word for that; just look at the reviews of those companies that you mentioned. Toyota doesn't want their name associated with those type of refurbished packs that just last a few more months or years - and I don't blame them. Toyota sends your return "core" packs for professional refurbishment; which means ALL new battery modules and comprehensive testing to ensure they meet their standards. Something they can warranty and stand behind. Dealerships operating cost are high; unlike a small business that's allowed to cut corners and only employing one or two people.

    Believe what you will - It's a free country; for now......
     
    #46 BiomedO1, Apr 1, 2026 at 5:17 PM
    Last edited: Apr 1, 2026 at 5:28 PM
  7. VelvetFoot

    VelvetFoot Active Member

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    I recall a Canadian dude who said his car wouldn't start in the cold. I think it was a Prime.

    On line manual, 2026 PHEV, pg 85:

    upload_2026-4-1_18-57-47.png
     
  8. Paul Gregory

    Paul Gregory Senior Member

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    I was concerned about that at one time, but the extreme cold seems to have had no effect on my car.
     
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  9. VelvetFoot

    VelvetFoot Active Member

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  10. mva

    mva Member

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    In the video attached the battery appears to be very serviceable. It takes some significant effort to remove it and open it up but the cooler can definitely be replaced. See video:

     
  11. DOHCtor

    DOHCtor Member

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    Q-Is cabin heat "free" if a Prime is in HV mode?

    A-Nothing is free. Forget what the government told you...
     
  12. Paul Gregory

    Paul Gregory Senior Member

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    Especially energy. It's never free.
     
  13. Will B

    Will B Active Member

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    @Prodigyplace : Yea,here it is a muggy day if the humidity is over 20%! :) We are in a desert, we just don't acknowledge that so water the heck out of our lawns trying to convince ourselves its not a desert.
    @Quovadis007 : Thanks, that is the kind of weirdness (in a good way) I was wondering might exist. It makes sense that they'd need to heat up the battery if it were cold. That should happen whether I have cabin heat or not. That still bodes mostly good for not using battery power for cabin heat.
    @BiomedO1 : I figured there are big differences between regular hybrids and PHEVs, so that is good clarification, thanks. ...and yes, I only consider this if it is just cold. If I need defogging, that (and the engine) are on right away. To my point to @Prodigyplace, the need for defogging here is rare--even with more than me in the car!
    @Paul Gregory : -42 is awful cold! I've only recall starting trips as low as -10.
    @Paul Gregory and @VelvetFoot : Luckily my car is garaged most of the time, not officially a heated garage, just poorly insulated from the rest of the house, so that helps. We moved recently so my car has been outside for several winter months while we use the garage for staging. It was very interesting to note how much more frequently the engine came on even without an empty battery. I am assuming that was related to a cold battery and the car deciding it needed the engine to make up for reduced battery draw.
    @DOHCtor and @Paul Gregory : Yea, that is why "free" was in quotes! :). Not fully free, but if my assumption about it being mostly from engine waste heat once the engine is warmed up, hopefully close.

    THANKS ALL for the great discussion and information! (and fun diversions about batteries too) Nice to know that heat mostly free. And for @Paul Gregory, I only do this when I feel like tinkering, so no stress. If I have passengers or just decide I want comfort, AUTO is right there--and I use it.

    will
     
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  14. Gokhan

    Gokhan Senior Member

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    Yep, it never occurred to me before this thread that you could adjust the cabin temperature even when the electric A/C (heat pump) is off by using the radiator heater core or outside cool air, as long as you turn on the blower fan. I had to check the manual.
     
  15. hill

    hill High Fiber Member

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    "I beg your pardon?"
    says Mr. sun
     
  16. Paul Gregory

    Paul Gregory Senior Member

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    Do you know a free way to harness it?
     
  17. hill

    hill High Fiber Member

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    don't need to harnesses - photosynthesis - & w/ the frequent enough showers - by the end of summer we get plenty of apples, cherries, raspberries, plums, pears & apricots.
    all we gotta buy - is toilet paper for all that fiber.
     
  18. Paul Gregory

    Paul Gregory Senior Member

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    Last time I checked, fruits and vegetables weren't free either.
     
  19. Paul Gregory

    Paul Gregory Senior Member

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    Nothing is actually free; even a gift was paid for by someone.
     
  20. hill

    hill High Fiber Member

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    almost forgot! besides our fruit bushes & trees, there's also free "air". heheheee
    free gravity too.