My HV battery is at 8 bars and reads 62% charge on Hybrid Assistant phone app

Discussion in 'Gen 2 Prius Main Forum' started by ski.dive, Sep 25, 2025.

  1. ski.dive

    ski.dive Active Member

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    Is 62% charge still a decent percentage for the hybrid battery with 8 bars?
     
  2. bisco

    bisco cookie crumbler

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    oh ya, you're good to go for the long run. think about it, you've lost 38% in 17 years. that's only 2%/yr.
     
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  3. ChapmanF

    ChapmanF Senior Member

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    Is the 62% shown in HA a state-of-charge reading, or some kind of life-of-battery estimate?

    My guess was it was state-of-charge, and sounded just fine to me. The actual % charge range the car tries to stay in is no lower than 40% and no higher than 80% (with rare exceptions), and the car tries hard to be right around 60% in the middle nearly all of the time (so it has energy to give you if you mash the go pedal, and also has room to store energy if you use the brake).

    The bar graph on the dash does not cover a full 0% to 100% charge range, but is more like zoomed in to the 40% to 80% range the car likes to use. A 62% actual state of charge will be shown somewhere in the upper range of the bar graph.
     
  4. Hayslayer

    Hayslayer Member

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    I'm pretty sure the Gen 2 MFD only has 8 bars total for displaying Hv battery status.
    If SOC is ~40%, only the bottom 2 bars will be on and will be purplish.
    If SOC is ~>40 and <~62% up to 6 bars will be lit and will be bluish
    If SOC is >~62% through ~80% the 7th and 8th will come on and all bars will be green.

    8 bars and 62% SOC sounds off a bit to me. At 62%, it should be either 6 blue bars or barely hitting 7 green.
    This is also based on Techstream readings, not HA. Idk the accuracy HA, but you would think it reads directly from the car ecu.
     
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  5. ski.dive

    ski.dive Active Member

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    CORRECTION-
    I have 6 blue bars not 8 blue bars
    6 blue bars-reads 62% charge on Hybrid Assistant phone app
     
  6. ChapmanF

    ChapmanF Senior Member

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    Sounds just about right.

    I suspect, too, that the scaling between actual SoC and number of bars displayed is fixed, and so won't really be something that tells you anything about battery health.
     
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  7. dolj

    dolj Senior Member

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    According to a post I read a long while ago, there is a measurable overlap between SoC and the bar displayed. I don't think that changes the second half of the sentence, though.

    Here is the graphic I harvested from that post, as I found it interesting.

    Prius Complex SOC.jpg
     
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  8. ChapmanF

    ChapmanF Senior Member

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    Interesting. What I meant by 'fixed' could include that: to have hysteresis, there'd be different SoC points when going down vs. going up for changing to the next lower or higher bar, but I suspect that's all in the ECU firmware from the factory and doesn't, for example, change over time to reflect battery aging.
     
  9. qmanqman

    qmanqman Active Member

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    I believe the bottom to top range of the 10 bars is 40-80%. With 10 bars total that would mean each bar is 4 percent. So five bars should be 40% + (5x4%) = 60%

    So ya, sounds about right
     
  10. dolj

    dolj Senior Member

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    There are only eight bars on the Gen 2 Energy Monitor Screen.

    Five bars is 52% to 57.5%.
    Six bars is 55% - 66.5%.

    Each bar is not linear; there is overlap between bars. Complete information is shown in the graphic in Post #7.
     
    #10 dolj, Oct 8, 2025 at 9:56 PM
    Last edited: Oct 8, 2025 at 10:01 PM