Cold weather - tried something new

Discussion in 'Prime Main Forum (2017-Current)' started by Lee Jay, Feb 20, 2018.

  1. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,920
    3,547
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    It was 9°F at my house and 0°F at work this morning so I knew the ICE would start to provide heat. Since the car was in a 40°F garage all night and the sun was out, I thought I'd try with the heat off so I turned it off as soon as I got in, turned the seat heater on high and turned on the steering wheel heater.

    The car stayed in Ev the entire trip, I got to work with more remaining charge than on a normal day, and I was pretty decently comfortable in the warm seat and with the warm wheel with no gloves. I was wearing my heavy winter coat. The only issue was windows fogging up and I solved that by cracking the windows for a few seconds. Obviously, the air in the car was very cold, but I wasn't uncomfortable.
     
    huskers, Wuzki, bwilson4web and 3 others like this.
  2. Dm84

    Dm84 Member

    Joined:
    Aug 30, 2017
    60
    37
    0
    Location:
    MA
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    Or you could be a totally normal person and run the ICE and not resort to freezing your nice person off and opening and closing the windows constantly.
     
    Dudley1030, Wuzki and jaqueh like this.
  3. ct89

    ct89 Active Member

    Joined:
    Dec 31, 2010
    323
    263
    1
    Location:
    New England
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I've done this as well...Starting from a warm garage, and with the seat heaters on, the car is comfortable without engaging the AC...
    I would not resort to freezing to save an ounce of gas...But in this case the car was comfortable. Now after being at work all day in sub-freezing temps, I turned the heater on immediately...No consideration of doing anything else.

    The difficult problem is when I forget to take a coat to work...I'm just fine leaving the house and getting to the office...The short walk from the parking lot to the door is OK without a heavy coat...But the first 5-10 minutes of the trip home really reminds me why I shouldn't leave the coat at home...
     
  4. huskers

    huskers Senior Member

    Joined:
    Aug 21, 2005
    2,474
    2,377
    0
    Location:
    Nebraska
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I have done this as well...the seat warmer and steering wheel seem to provide all the heat I need when 17 degrees or up.

    (We had thunder sleet here last night. 1st time I have ever experienced that...weird night.)
     
  5. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,920
    3,547
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    As I said, I wasn't uncomfortable (the car was in the garage all night, I had a heavy coat on, and I was in a heated seat with a heated wheel), and I only cracked the windows twice for about 10 seconds each.

    This was also just an experiment. Best way to learn new things is to try something new. I tried something new in the exact opposite direction here:

    My first trip through the mountains | PriusChat

    "When we got in, the battery was at 74% so I decided to put the car in charge mode to generate as much heat as possible by running the engine harder than idle."
     
  6. Washingtonian

    Washingtonian Active Member

    Joined:
    May 26, 2017
    405
    377
    0
    Location:
    Western Washington
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I am not a Prime expert, but I thought that heating and cooling was handled by a heat pump. I have one in my house and of course it runs on electricity. I also know that heat pumps are not efficient below something like 30 degrees Fahrenheit as they work by extracting existing heat from the air. Is there a temperature at which the heat pump in the prime no longer comes on?
     
  7. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,920
    3,547
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    The heat pump in the Prime is a gas-injected heat pump which keeps it efficient down to around 14°F. Below that, it starts the ICE for heat. That's the point of what I tried.
     
  8. DavidA

    DavidA Prius owner since July 2009

    Joined:
    Jul 14, 2009
    2,155
    1,618
    18
    Location:
    Chicago western burbs
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    That. The warmer temp of the batteries + the air temp sensor (which is different than what the battery temp is) allowed it to start in EV. Had the batteries cold-soaked at 9 degrees F all night, it would be instant HV start before you could even reach to turn on any cabin heat, steering wheel heat or seats.
     
    #8 DavidA, Feb 20, 2018
    Last edited: Feb 20, 2018
  9. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,920
    3,547
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Could be. I did cold soak it outside through the night at 16°F once and it stayed in Ev for that trip. But I haven't tried it colder than that.
     
  10. DavidA

    DavidA Prius owner since July 2009

    Joined:
    Jul 14, 2009
    2,155
    1,618
    18
    Location:
    Chicago western burbs
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    Thing is, the batteries will "ride" the warmer air for a while (hours). Let's say it is 25 degrees F in the day (EV works) and it cools down to 12 or 13 at night, then warming back up again for the daytime. There might be a delay in the battery section getting to that 12 degrees, so if may very well still be ~16 or higher at the sensor where it counts. If it stayed at 14-15 for a day or more, then the HV will probably kick on as soon as you hit the power button.

    On several occasions this winter, the nightly cold soaking (I don't have a usable garage) to temps at around 13-16 have either resulted in instantaneous HV, or a "What the...? Really?" starting and staying in EV mode -- on the way to work (but not if I hit defrost, cabin heat, or the like).
     
  11. Dm84

    Dm84 Member

    Joined:
    Aug 30, 2017
    60
    37
    0
    Location:
    MA
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    Not could be. Definitely. I don't have a garage. If it's below say 18 degrees out or so the car will run the ICE on startup regardless of anything else.
     
  12. Lee Jay

    Lee Jay Senior Member

    Joined:
    Jun 25, 2009
    4,920
    3,547
    0
    Location:
    Westminster, Colorado
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    I did something similar this morning but this time I ran two remote A/C warmup cycles while it was still in the garage. The car was warm and toasty when I got in and I got heat from the heat pump for a little while after I started driving. However, I had to start the ICE this time because it was both colder outside (~6F) and because the near 100% humidity (patchy fog) resulted in much more aggressive window fogging. Two shots with the ICE to defog the windows was sufficient and I still got 115MPG going uphill to work and managed to consume 55% of the battery on the way.
     
    bwilson4web likes this.
Loading...