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Does the car remap or recalibrate the HV battery?

Discussion in 'Gen 3 Prius Technical Discussion' started by GrumpyCabbie, Jan 1, 2013.

  1. GrumpyCabbie

    GrumpyCabbie Senior Member

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    As per the title, does the car remap or recalibrate the HV battery parameters depending on use?

    The reason I ask is that I used to be a taxi driver giving the car a hard life in slow, crawling, stop start traffic for 10+ hours a day. I then left the taxi world and am back on the corporate ladder with a 60 mile (30 each way) daily commute with minimal stop start driving. Apart from seeing my mpg's climb up nicely I noticed something weird happen which I'll try and explain below.

    When I used the car as a taxi I noticed that the HV battery didn't quite hold the same charge as when new in that it wouldn't go far on electric when in slow traffic before the engine kicked in. The daily average mpg's were the same but the distance travelled on electric was noticeably shorter. At the time I thought it was due to a failing or aging HV battery.

    After about 6 weeks of my new usage patterns with my easy (on the car) commute, one evening I noticed a weird happening with the HV battery levels in that they were 3 bars from top for ages and just wouldn't go higher, then they went to 1 bar from full and stayed there for a longer time than I'd ever noticed before. At this point I entered my home town and the car seemed to stay on electric much more often in the slow traffic and for a much further distance. I thought it was a one off or maybe even a problem developing, but since then the car is much more economical, happier to cruise in start stop traffic on electric for much much longer.

    So has my car noticed that I am no longer a taxi driver and recalibrated the HV battery usage? Or, put it another way, did the car realise I was previously driving it in a way that could cause premature HV battery failure (taxi use) and restrict the HV battery usage window over and above normal to protect itself? My experience indicates it did or has, as I can now drive from one end of town to another on electric; more than double what it would allow previously.

    Or is it all a big coincidence? :)
     
    #1 GrumpyCabbie, Jan 1, 2013
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  2. spiderman

    spiderman wretched

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    simple answer is yes. If you want to reset what the car has "learned", simply diaconnect the 12v battery. But in this case you wouldn't to since it has learned well your driving pattern.
     
    #2 spiderman, Jan 1, 2013
  3. GrumpyCabbie

    GrumpyCabbie Senior Member

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    But I understand cars 'learn' your usage patterns, but not to the severe extent which this appears to have been.
     
    #3 GrumpyCabbie, Jan 1, 2013
  4. spiderman

    spiderman wretched

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    Well if it can "learn" at all, why not to extremes? There was a good thread about this subject a long while back, still trying to find it.

    Happy New Years, by the way GC!
     
    #4 spiderman, Jan 1, 2013
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  5. SteveLee

    SteveLee Active Member

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    I usually drive in relatively open areas with considerable highway use. My HV battery bar chart rarely goes lower than 4 bars below the top an mostly stays at 2-3 bars from top. Last night we drove quite a bit in a larger city in slow stop and go traffic. The bars were way down and would not recoup in that environment. But after a few minutes back on the highway all was good again. From what I have read speed and torque demands partially determine the type or phase of operation for the HSD. It may not be as much about learning as it is a direct reaction to the driving environment/demands. I can see where staying in that environment would prevent the HVB from fully charging while it is being demanded to supply power at lower speeds.

    There is some info about the HSD here.
    Hybrid Synergy Drive - Wikipedia, the free encyclopedia
     
    #5 SteveLee, Jan 1, 2013
  6. GrumpyCabbie

    GrumpyCabbie Senior Member

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    It would often go down to 2 bars in heavy traffic but would do that from full in only half a mile, whereas now when I hit that type of traffic again, it will run a good mile or mile and a half before hitting 2 bars. It's as if the battery is now utilised over a wider window than previous.

    I think the HV battery is used in a window between 40% and 70% or something like that. I wonder if the car is used in town more often, then the window is reduced to between 50% to 65% so as to allow it to last?

    All speculation but the car is definitely different to the 3 years of 10+ hour experience I have had of it.
     
    #6 GrumpyCabbie, Jan 1, 2013
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