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Charging across midnight

Discussion in 'Gen 5 Prime Charging' started by Will B, Sep 15, 2023.

  1. Will B

    Will B Active Member

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    I tried a scheduled charge crossing midnight and it didn't work as expected. My battery was dead and I wanted a full charge by 6am, so set the timer for a 6pm start and 6am end. For the day I set it for the starting day. Weirdly, charging stopped at midnight and the battery didn't fully charge. I guess if the schedule crosses midnight you are supposed to select both days? I had assumed it was just the starting day. Guess not. I'll confirm that the next time I do another "across midnight" charge.

    will
     
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  2. Blizzard_Persona

    Blizzard_Persona Senior Member

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    Is this done on the screen inside the car or do you have a level two charger that is programmable?
     
  3. BiomedO1

    BiomedO1 Senior Member

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    You can set a stop charge time on the gen 5? Could you have accidentally told the car to stop charging at 0600 on the same day, not the next day?
     
  4. Louis19

    Louis19 Active Member

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    Maybe try to program a departure time for 6 AM, on the shedule instead of starting time.
    On the Gen 4 prime this does not stumble on midnight . I programmed it for every day of the week in Departure time. If i don't need it I simply do not plug the car , if i need an immediate charge I simply plug it in, wait for the flashing green light , remove the connector and plug it right back, this overides the program for this event only, and start a immediate charge:D
     
    #4 Louis19, Sep 16, 2023
    Last edited: Sep 16, 2023
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  5. Will B

    Will B Active Member

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    All: Thanks for the questions.
    - I am using the level 1 charger that came with the car
    - I am using the Prius's charging schedule feature. I'm using the phone, but it and the car seem to sync well.
    - Biomed: I am setting the end time, but must set the start time too, so make it a wide window.

    I tried another charge session last night with both days highlighted (see screen shot). The car started charging dutifully at 9pm on Friday as I would have expected, but STILL it stopped charging at midnight??!!! I can see the need for selecting the second day after the charge starts as a difference of opinion on how the charging UI should behave, but still stopping at midnight with the settings below borders on a software bug???? Is there something I'm missing here?

    Even when not spanning midnight and setting and end time, it still doesn't seem to be behaving as I would expect. Even if I set a wide window, the car just starts charging at the start time and ends when it fills up. Since I set a wide window, the charge is full well before the
    set end time. I thought it is supposed to only start charging just in time to fill the battery by the end time. Is there some way to set only the end time? If so, I can't see it.

    Screenshot.jpg
     

    Attached Files:

  6. BiomedO1

    BiomedO1 Senior Member

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    The phone app is buggy. When Toyota asked me to renew - I laughed at them. Why should I pay for something that doesn't work. The app does work for checking the cars' status and tire inflation, but the rest of it was hit & miss.

    You may be misinterpreting the app. Try setting schedule directly from the cars' MID. That's direct access to the car's computer. My 2021 Prime never had issues with charging schedules - Once I figured out that the dealer inputted the wrong date into my car's computer. That's something you should check also.

    On the Gen 4, we don't have 'end time', we have departure time. The car will calculate how long it needs to charge to get to 100%, then start charging the car, so you'll be full by departure time.
     
  7. Will B

    Will B Active Member

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    Biomed: OK, will try using the MID instead of the phone next time. I need a full charge again first thing tomorrow so just going to do a non-timed charge tonight. Glad to know I'm not confused on how it is supposed to work.

    will
     
  8. Louis19

    Louis19 Active Member

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    Using the MID is the only way for a successful charge , here in Canada the phone app does not provide any charging at all for my Gen 4 Prime
     
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  9. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    Why do you need/want to set an end time?

    No such animal on 2023 Prime
     
    #9 tovli, Sep 18, 2023
    Last edited by a moderator: Feb 14, 2024
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  10. bisco

    bisco cookie crumbler

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    well, an end time would be the same thing with different nomenclature.

    on the older plug ins, you either set a start time or an end time, but not both. otherwise, you were messing with the computers brain
     
  11. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    You are correct - in the 2023 Primes there is no "only set end time" or "start when needed to finish by this end time"

    You must set a start time, or use the stupidly insufficient "Eco midnight to 5am". If you set a start time, you may set an end time for the charging to stop regardless of state of charge.

    The question remains how to obtain a full charge that will cross the midnight?

    It seems @Will B tried start with 9pm no end time and the charging stopped at midnight , so perhaps this would restart the charge to continue till complete?

    IMG_4734.PNG
     
  12. Will B

    Will B Active Member

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    Tovli: To your earlier question, the reason I'm wanting to set the end time is the general idea to not have your battery at 100% for longer than necessary, so ideally want to to reach 100% right as I'm about to take off on a trip. Sounds like it is a new name for "departure time" on older Primes. While not a big deal for short in-town trips, when I have a trip that is longer than 40 miles, would like to get as many battery miles as possible.

    Yea, I thought about using two timers, one to midnight then another after midnight, but if that is the only solution, the Toyota folk need a slap upside the head! :) That would be necessary compensation for the face palm plant I'd have to do to myself first! Not thinking about a timed charge crossing midnight would be

    Bisco: Agree, you should have a start time or end time. Throw in charge time and you can pick only two and the third must be computed.

    My next 100+ mile trip is Friday, I'll try using just the MID to set up a cross-midnight charge Thursday so that if it doesn't work I'll go back to "dumb" charging Thursday night for my Friday trip.

    will
     
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  13. Hammersmith

    Hammersmith Senior Member

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    Multiple charge schedules won't work. The manual says the plug must be removed and reinserted between scheduled charges.

    Pg. 125


    There is no gen5 counterpart to the old Departure Time charging method. Reading between the lines, I suspect Toyota engineers believe battery technology and battery management improvements have reached the point where user micromanagement is no longer necessary. The only reasons for the scheduling function now are either to take advantage of off-peak electric rates or to make sure you don't blow a breaker by having too much draw on the same circuit(like trying to charge two vehicles at once).

    Just my opinions.
     
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  14. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    You nailed that one!

    Given that we let Toyota manage our prior gen non-prime batteries and the batteries long outlasted the warranty for most users, I am leaving battery management totally to Toyota in my 2023 Prime.

    I charge from 2am and the car sits at 100% for a few hours till I open the barn doors for some more fun. Perhaps I am too much of a fan-boy after 14 great years driving a Prius, I am counting on Toyota to maximize the battery life.
     
    #14 tovli, Sep 18, 2023
    Last edited by a moderator: Feb 14, 2024
  15. Will B

    Will B Active Member

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    Hammersmith and tovli: Those are good points and given I'm giving away my 20-year-old Gen1 Prius that still has its original traction battery and it is still good, my anecdotal data certainly supports that point. The strong advice about not leaving your battery at 100% is mostly generic info about electric cars in general and tangentially mention hybrids. I did some scanning of the manual and can only find one reference on page 113:
    "Use the charging schedule function
    as much as possible in order
    to fully charge the hybrid battery
    (traction battery) immediately
    before starting off. (P.123)"

    Page 123 is just the mechanics of charging. So, they do say it's important under the section on battery longevity and even say the charging schedule is there for that maintenance, but certainly not over-emphasized.

    Bummer on two schedules likely not working. Regardless of the nuances of battery life, Toyota still deserves a head-slap for an extremely sloppy battery charging implementation that forgot about midnight. I'm a hardware guy and I'm pretty sure I'd have at least tested that use case and found the bug.

    will
     
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  16. Blizzard_Persona

    Blizzard_Persona Senior Member

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    Our cars have a large safety threshold on the top and bottom of the battery range. They apparently will never fully charge 100% nor will they deplete to 0%. No need at all to “only charge to 80% unless leaving on a road trip” like Tesla.

    Well on the primes 0% charge remaining simply means it reverts back to regular hybrid mode. What that battery level is, is whatever the toyota engineers deemed was needed to keep the prime running at 220 hp in HV ;)

    It is a PHEV, fully charging everyday is what’s it is designed for and what I will be doing. Granted sure you can also drive it in HV solely but why? Haha.
     
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  17. Louis19

    Louis19 Active Member

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    Thanks , good to know .....but I wonder why(n)
     
  18. Will B

    Will B Active Member

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    Louis: I agree, makes no sense. I like the idea of them doing enough battery management that it doesn't jive with the manual. I'm hoping it is an oversight that will get addressed sometime soon.

    BTW, is there some official place to ask Toyota? I know it isn't the dealership.

    will
     
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  19. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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  20. BiomedO1

    BiomedO1 Senior Member

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    IMHO; all you Gen 5 owners should scream loudly at Toyota to fix this issue. Thus could be easily handled by a software patch. Toyota will fix it, if there's enough complaints.