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2017 prime traction battery voltage

Discussion in 'Prime Technical Discussion' started by Mattg89, Dec 10, 2020.

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  1. Mattg89

    Mattg89 New Member

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    So I have noticed over some time now my milage in EV mode has decreased a good bit. If I try my hardest I can get maybe 21 miles on EV only where I uses to be able to get 30 miles. So for the fun of it I bought an obd2 sensor and downloaded the dr prius app and have spent some time watching my battery over a week or so. I have noticed I belive blade/cell whatever we call it 26 or 27 never moves it is always in the white. Has anyone played around on dr prius and could tell me is this something normal? Or is that cell not holding a charge. I assume the blade voltage that is displayed is just in average for the entire battery pack. I also have noticed when I charge at the public station at work from about 17% charge when the EV mode is no longer available a full charge gives me about 4.4kwh I feel like that is kind of low and would assume it should be closer to 5 to 6kwh given math or is the EV mode literally only 50% of the 8.8kwh
     

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    #1 Mattg89, Dec 10, 2020
  2. bisco

    bisco cookie crumbler

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    has it been getting colder there?
     
    #2 bisco, Dec 10, 2020
  3. vvillovv

    vvillovv Senior Member

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    You can compare what you're seeing now to these screen grabs when temps were 10 to 20 degrees warmer
    add your pics and info if interested in sharing.
    Prime Traction Pack voltage report | PriusChat

    DrPrius is showing Voltage Dif as 0.01 which is as close is it gets... The graph makes it look like the voltage dif is all over the place... just pay attention to the Voltage dif reading.

    If you sit in the car after plugging in and press the start button twice (foot off brake) you can see charge levels on DrPrius for two minutes, before automatic shutoff. Notice how the charge level tappers from a max of around 8.6 amps (240 volt charger) down to 8.2 after about 45 minutes, than down further, after around ah hour and a half.

    Yep. somewhere between 5 and 6 kw make it to the wheels after losses.
    losses get bigger as temps decrease, I estimated around 1kw every 20 degree F starting at 90 F (lots of variables in that estimate)
    I saw a noticeable decrease this year below 60 F. But the car has been driven a lot differently than year one and two.
     
    #3 vvillovv, Dec 11, 2020
    Last edited: Dec 11, 2020
  4. jerrymildred

    jerrymildred Senior Member

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    Welcome!

    This does seem low. Makes me wonder if it's accurate.

    This is not a measure of battery capacity. It's a measure of capacity divided by efficiency. Take that 21 miles and divide it by the miles/kWh your eco stats show and you'll have the battery capacity. I'm guessing that, in the current wintery temperatures, you're only getting about 3.5 miles/kWh.

    ^^^This!^^^
     
    #4 jerrymildred, Dec 11, 2020
  5. Salamander_King

    Salamander_King Senior Member

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    What @jerrymildred said above, but if I add a bit more of my opinion.
    The loss of EV range happened suddenly? If it is seasonal changes, 21 miles EV is not all that unusual. I can get 35 miles EV range in summer, but that gets down to 18 miles in winter. Yeah, check your Eco Diary to see what miles/kWh values you have been getting recently.

    What do you mean by "from about 17% charge"? If the dash is showing you still have a 17% traction battery charge, then it is strange that you are saying "when the EV mode is no longer available". Even if you are referring 17% to the real traction battery SoC that you can find out via OBD, it is still a bit higher than when the EV mode is no longer available. Usually ~11% real SoC corresponds to 0% SoC on the dash.
     
    #5 Salamander_King, Dec 11, 2020
    jerrymildred likes this.
  6. Mattg89

    Mattg89 New Member

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    This was the same over the summer probably first noticed a reduction last year. Its still not too cold here yet
     
    #6 Mattg89, Dec 12, 2020
  7. Mattg89

    Mattg89 New Member

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    I have realized the lower efficiency is being caused by a tire change I did back in the spring. I went from the factory tires to michelin defenders. Toyota puts factory tires with zero grip in order to milk out the efficiency so as soon as you out higher traction tires on it destroys your milage. I am averaging 3.0m/kwh highway and 4.4 city now. I never really paid any attention to the eco diary before. I guess you have to choose between fuel economy tires with horrible traction or loss of economy with traction. The cost of friction.
     
    #7 Mattg89, Jan 2, 2021
  8. jerrymildred

    jerrymildred Senior Member

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    You can, but you don't have to. I put on Yokohama Avid Ascend GT tires and they have great grip, especially in the rain. Once they broke in, my miles per kWh went right back to what I got with the Toyo Nanos it came with originally.
     
    #8 jerrymildred, Jan 2, 2021
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