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HV Battery charging

Discussion in 'Prius c Technical Discussion' started by steelphoenix3, Sep 15, 2015.

  1. steelphoenix3

    steelphoenix3 New Member

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    Good evening, everybody.
    .
    I'm wondering if there's a way to force the ICE to charge the HV battery, either while standing or driving. Currently, EV Mode kicks in while coasting down a hill, and I would rather use those moments to effectively charge the battery rather than trickle charge with what little gain that gravity gives me.
    .
    I know there was a way on other models to charge the battery while standing by depressing the accelerator in park (or in drive with the brake depressed), but neither method works with the 2015 Prius C. The battery continues to drain while the ICE runs in park, and it refuses to run in D or B while the brake and accelerator are pressed at the same time.
    .
    Thank you in advance for any assistance you might provide. Also, my apologies for being slow to reply. Over here, things get kinda hectic sometimes. Life is what happens while you're busy making other plans. :)
     
  2. SquallLHeart

    SquallLHeart The Techie Guy

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    i don't think i've heard the accelerator trick not working before.. forcing the ICE to turn on my mashing the pedal to the floor while in P or while holding the brake down was always the method used.

    even depressed to the floor, the ICE won't turn on?
     
  3. steelphoenix3

    steelphoenix3 New Member

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    Oh, it turns on alright. It even increases or decreases the idle speed as the petal level varies. However, despite the ICE running, it was not charging the battery at all, and it was diminishing over time, as if it wasn't running at all.
    .
    Most electronics in the cab were off, as was all blower function. (A/C et cetera) The only things on were the displays. It's a headscratcher.
     
  4. SquallLHeart

    SquallLHeart The Techie Guy

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    hmm.. what level is the HV battery showing at to begin with? i'm thinking the car might be preventing you from overcharging it if you're starting out higher... there's a whole... prolonging the life of the battery thing.. i'm sure.. that is a factor in play.
     
  5. steelphoenix3

    steelphoenix3 New Member

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    My battery display is out of 10 bars, and both the top two, and bottom two are restricted under normal circumstances.
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    When I tested this yesterday, it started out at 6/10, and dropped down to 2/10. (Which is when the HV began charging back to 3/10, but it would've done that no matter what.)
    .
    Perhaps I'm a control freak, but I'd like to have control over my vehicle's operation. The way my neighborhood is laid out, it's beneficial to leave in the mornings using EV mode for a while, and it's tough to do that with a drained battery. :/
     
  6. SquallLHeart

    SquallLHeart The Techie Guy

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    yeah.. understandable. the car does what it does sometimes...

    everytime i start up my car.. EV mode, more often than not, is unavailable because the ICE wants to warm up.
     
  7. steelphoenix3

    steelphoenix3 New Member

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    Warming up makes sense to me, and I'm happy that it's smart enough to do that. :)
    .
    At some point, I'm gonna get aggravated enough to hack into it and create a manual override to force ICE mode. (It'll probably be something simple like giving a false reading for battery voltage so it prevents EV mode while the switch is active. Should be fun.)
    .
    Anybody wanna help me with that project?
     
  8. TheTimob

    TheTimob Member

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    The car is programmed to do absolutely everything it can to keep the HV battery at 60% - when you're below 60 - it'll "siphon" off an extra 30 amps from the ICE while driving. If you're over 60 - it's going to add 20 or 30 amps to drain it down back to 60, and switch to EV mode more quickly.

    The main reason for this 60% level is to extend the life of the battery as long as possible. I've seen the battery go as high as 76%, and as low as 30%. Below 30 - it starts running the ICE at high speed to emergency charge as quickly as possible. When it's way above 70 - you can be in EV mode above the middle bar of the Hybrid System Indicator, and using all kinds of extra assist while the ICE is on getting crazy MPG.

    You're exactly right about how to hack it though - some of the Prius PHEV kits do this by spoofing battery state-of-charge data on the CANBUS to make the car run in EV mode much more. If you spoof a rather low SOC while driving down a hill - you might make it go into that crazy emergency charge cycle.
     
    Mendel Leisk and Freeekonaleesh2 like this.
  9. Garycs

    Garycs Junior Member

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    Steelphoenix3:

    I am interested in ding exactly that.
    Maybe I am also a control freak or I just can't leave it alone. I want to leave the house and also leave work with a full charge then try to force the car to use only the battery down to 30% charge. I have a link to a 350 Mah charger schematic using LED drivers which is probably not big enough. I found out yesterday that the C battery pack is 7Ah. so I need ~5 amp charger at 144 V. However I also need the ability to change the firmware. I found one guy in CA that sells software that seems to have some capability to get into Toyota firmware. I like the idea of spoofing the battery voltage though since it may be a lot easier. Have you found any information regarding either approach?

    Gary
     
  10. bisco

    bisco cookie crumbler

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    nope.
     
  11. bisco

    bisco cookie crumbler

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    have you thought of connecting a portable solar panel on the roof?
     
  12. Mendel Leisk

    Mendel Leisk Book Cover Judge

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    I think you're chasing something with little or no benefit. I know, from experience, lol.
     
  13. TheTimob

    TheTimob Member

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    There's a company selling grid chargers for our cars - Hybrid Automotive makes the Prolong Battery systems. They can fill the battery completely, but it takes a LONG time.