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Prime Depart at time finishes early

Discussion in 'Prime Plug-in Charging' started by DenierwithPrius, Jan 19, 2019.

  1. DenierwithPrius

    DenierwithPrius Junior Member

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    I keep finding my charger finished long before scheduled departure time.
    I think this is to allow the battery to cool before driving.
    However I have seen posts indicating 70F (ambient) to be the optimal mi/kw efficiency.
    It is about 25F (ambient) now so I want the battery heated and the car A/C heated at departure time.

    Are there schedule settings to make it finish charging at departure time? Is this a good idea?

    Also does anyone have an idea at what temperature the traction battery heater kicks in?

    My other problem is that sometimes I drive to a place with free charging.
    I have to do the math to program 'start charge at' time so that when I depart I have just enough capacity to get there. Is there any way to have the A/C heated in this situation?
     
  2. Andyprius1

    Andyprius1 Senior Member

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    Never had 1st problem
    Before exiting car set your heater to where you want it, then power off.
    You cannot charge less without affecting the normal and the AC precondition.
    I don’t think AC precondition can be programmed.
    When you do initiate AC precondition, a portion of the charge gets used for heating / cooling
    then the car charges again to return to whatever normal charge usually is.
    Traction battery Heater: I didn’t even know it had one, If so, I should be getting my summer ranges, after a charge. 30-35, if I remember right. But am only getting 20 miles.
    The reason for the cooling fans at the back seat is because the HV battery gets too HOT and requires the AC on, while driving.
    On 1st question, i have never checked to see if my charger was shutting off on time, Is your clock set right?
     
    #2 Andyprius1, Jan 19, 2019
    Last edited: Jan 19, 2019
  3. bisco

    bisco cookie crumbler

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    how much earlier than departure time?
     
  4. Andyprius1

    Andyprius1 Senior Member

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    3 days.....
     
  5. dave121

    dave121 Junior Member

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    I've noticed that I also seem to charge ahead of departure. In addition, I'm not sure if the climate control operates prior to departure even though its selected when setting charge for departure. I need to spend some time to figure this out, but one thing you can do is check your cars date / time setting...at delivery, mine was off by a day and the car wanted to charge for departure one day later than I needed initially.
     
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  6. DenierwithPrius

    DenierwithPrius Junior Member

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    It seems to be finishing charging about an hour ahead of the programmed depart at time. I have the clock correct. I know some folks have had an AM/PM issue.
     
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  7. dave121

    dave121 Junior Member

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    In addition to the clock, there’s a separate date setting buried in the menus somewhere. If it only an hour off though it’s probbaly not that.
     
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  8. KP7

    KP7 Member

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    This is normal and the same behavior I'm seeing on my energy monitor. I think it is partially because it slows down the charge near the end and partially because it is checking to make sure everything is OK with the battery after the charge.

    It may also be Toyota deciding that people would be angrier if they get into a car that is at 96% because they got in 10 min before the charge schedule departure vs. having it be ready too soon.
     
  9. VTBIGDOG

    VTBIGDOG Active Member

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    There is also. Daylight Savings Time toggle in the Menu.

    Posted via the PriusChat mobile app.
     
  10. DenierwithPrius

    DenierwithPrius Junior Member

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    Looks like Toyota ends charging early to let the battery cool.
    This works against me when it is 10F outside and I want a warm battery for improved efficiency.
    I Plugged in 12:25PM, set for 6:00PM departure.
    Set for slow 8A charge mode. Should take 4hrs20mins, but it started charging immediately.
    Finished charging 4:45PM.
    Heat kicked at 6PM. Capture.PNG
    [​IMG]
     
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  11. bisco

    bisco cookie crumbler

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    you can set start time instead
     
  12. Andyprius1

    Andyprius1 Senior Member

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    I don’t believe the EV Battery can be heated. Iv tried preheating the inside before arriving home, immediately charging after arriving, with a good Sun. Nothing increases the range, right now ( 20.6 )
    I believe the traction battery is intimitly aware of weather conditions.
     
  13. KP7

    KP7 Member

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    There is a heater for the traction battery to keep it above freezing. Kicks on before departure time when plugged in. I'm assuming it also kicks on when you start the car in the cold and haven't been plugged in.
     
  14. Marine Ray

    Marine Ray Senior Member

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    1 minute 40 seconds into this video starts you into deep dive into traction battery heater. At 6 min 40 sec video indicates that traction battery heater kicks on when temp sensor reads below 35.6 F (2C) and turns off at 41 F (5C) - and only if you've plugged in your Prime.

     
  15. KP7

    KP7 Member

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    Thanks for posting. Great to know the specifics of the heater.