Dr Prius results

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bdc101, Nov 26, 2023.

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  1. bdc101

    bdc101 Member

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    Vehicle:
    2010 Prius
    Model:
    ----USA----
    So by 59%, is it saying the watt-hour capacity of the battery is only 59% of what it was new?

    Or is it saying the battery still holds the rated energy capacity, but has only 59% of its life expectancy left?

    I'm a little confused about what it means by that number.
     
    #21 bdc101, Dec 5, 2023
  2. PriusCamper

    PriusCamper Senior Member

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    It's basically taking some snapshots of what your pack is currently looking like at this moment and then does some math to get that number. If you try again in a few days with different weather & driving conditions, you'll likely get a different number.

    I'm a huge fan of Dr. Prius app. I even sometimes work for the guy who created it. But I don't use these tests... I mainly focus on monitoring "Voltage Diff" which is the first place you'll notice a battery go bad when that number goes consistently higher under high amp loads.
     
    #22 PriusCamper, Dec 5, 2023
    bdc101 likes this.
  3. bdc101

    bdc101 Member

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    Vehicle:
    2010 Prius
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    ----USA----
    I logged a couple of trips this afternoon and will plot out the CSVs later and report back. Tried to gun it a couple times and other times drive on electric to get good data.

    By voltage diff, do you mean cumulative voltage delta? Is that the difference in voltage from one pack to the next or what?

    Edit: I guess I'm confused about voltage diff verses CDV. Is CDV just the sum of all the cell voltage differences from the mean voltage or something?
     
    #23 bdc101, Dec 5, 2023
    Last edited: Dec 5, 2023
  4. PriusCamper

    PriusCamper Senior Member

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    It doesn't have anything to do with CDV. Simply put, "Voltage diff" is right in the middle of the readings on the screen because it's the most important. It means the amount of voltage in each of the 14 modules as compared to each other. When your battery pack gets old and starts to fail the first symptom of impending failure will be a lack of balance between blocks. Also the #1 easiest way to improve MPG from a battery pack is to ensure it is perfectly balance, as in very low to near 0.00 "voltage difference."
     
    #24 PriusCamper, Dec 5, 2023
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