fully charged indicated range is dropping?

Discussion in 'Prime Fuel Economy & EV Range' started by miket12, Jul 30, 2022.

  1. miket12

    miket12 Junior Member

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    I have a 2019 Prius Prime that is almost 3 years old since purchase. Up until about a month ago it would indicate 29 or 30 miles when fully charged overnite using the 120V charger. About a month ago it said 26.4 miles instead of the higher value, and this week it's saying 25.6 miles. The drop is a bit disconcerting. The weather has been normal for summer, perhaps around 80F during the hottest part of the day. Is this drop in capacity anything to worry about?
     
  2. jerrymildred

    jerrymildred Senior Member

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    Predicted EV range is no more of a battery capacity indicator than the DTE is of the gas tank capacity. Well, maybe a tiny bit more. Mostly it's an indication of how efficiently (or inefficiently) you've been driving. Go to your eco page and look at your miles/kWh history. That will tell you your efficiency and, unless you've been subjecting the car to extreme heat, will probably reveal the real reason for the reduced range.

    To measure capacity, put a kWh meter on the outlet you charge from and see how that kWh per charge compare. Keep in mind that it will fluctuate bases on how far you have dipped into the HV portion of the battery.
     
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  3. Bill Norton

    Bill Norton Senior Member

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    But 'Charging Loses'.
    What 'goes in' is not the kWh capacity of the pack.

    Plus EV/PHEV's have a thermal management system that cools or heats the pack as required, (the good ones;)) and that power usage shows up on the kWh meter.
     
  4. BiomedO1

    BiomedO1 Active Member

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    And your estimates are based on past practices; so if your using your A/C more - the computer is going to deduct the usage from your EV range. Since your going to getting less miles/Kwh.
    Jerry is correct, you need to look at your historic m/Kwh usage tables.
     
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  5. dbstoo

    dbstoo Active Member

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    MikeT12 is in the bay area, where we have been having temperatures as high as 100 degrees in recent weeks. I'm assuming that the "bay area" in his profile is the San Francisco bay area.

    I've found that it will show a higher range if you turn off the AC before shutting down the car. This is because the predicted range is based on the previous driving technique as well as the current settings. If the AC was used when you came home, it will still be "on" when you start the car in the morning. As soon as you turn the AC off the predicted range should increase. :)
     
  6. bisco

    bisco cookie crumbler

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    it's actually just the fan
     
  7. jerrymildred

    jerrymildred Senior Member

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    That overhead is a lot more consistent than the driving efficiency, but, yes, it fluctuates as does the SOC when you initiate charging. Measuring from one charge to the next is about like trying to figure gas mileage on a Gen 2. But over time, you will see a clear trend if there is one to be seen. Here's mine for the last 2-1/2 years as an example:
    Screen Shot 2022-05-23 at 2.31.32 PM.png
     
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