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Question about reserved capacity, which calculation is correct?

Discussion in 'Prime Main Forum (2017-2022)' started by Roy2001, May 30, 2018.

  1. Roy2001

    Roy2001 Active Member

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    I am interested to get a 2nd plugin hybrid and prefer a bigger one, so I went to Clarity forum. I argued with the guys there about reserved capacity. Here is the details:

    We all know Prime draws about 6.3kWh from wall, 6.3/8.8~=71%, so it reserves about 30% of the capacity not being used. Since EPA rating is 25 miles, (25/6.3)*33.6=133 MPGe which is what EPA rated as well.

    According to Clarity owners, it draws 14.7 kWh per charge with EPA 47 miles rating. (47/14.7)*33.6=107. this is pretty close to its EPA 110MPGe rating.

    14.7/17=86%. Now I told them that Clarity is only reserving about 15% of the capacity, they argue that due to conversion loss, the battery has only 12.5kWh charge even though it draws 14.7kWh. 12.5/17=73.5%, it reserves roughly 27% of the capacity.

    Now matter how, Prime reserves more capacity, hopefully that would result in longer battery life and less capacity lose. But I I wonder if their calculation is correct. Anyone can shed some light?
     
    #1 Roy2001, May 30, 2018
  2. bisco

    bisco cookie crumbler

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    no, but it wouldn't surprise me. honda has nothing to lose, their hybrid/phev rep is already in the toilet.
     
    #2 bisco, May 30, 2018
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  3. jaqueh

    jaqueh Active Member

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    The Clarity does have one thing the Prime doesn’t: a liquid cooled battery.
     
    #3 jaqueh, May 31, 2018
  4. Tideland Prius

    Tideland Prius Moderator of the North
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    Keep in mind that both have hybrid modes so there's a portion of the battery dedicated to that too (I'll wager it's just under 1kWh on the Prime).

    One of John's video shows the Prime's EV portion is 14% to 83% true SOC. (It also means one doesn't have to worry about fully charging the Prime all the time since fully charge is 83% which is roughly what other EVs charge to for longevity either as an option ["standard charge"] or what EV owners are manually limiting their charge to)
     
    #4 Tideland Prius, May 31, 2018
  5. triggerhappy007

    triggerhappy007 Active Member

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    If their Level 2 charging station is reporting it used 14.7 kWh and charging efficiency is about 90%, the usable capacity of their battery is about 13 kWh.
     
    #5 triggerhappy007, May 31, 2018
  6. Roy2001

    Roy2001 Active Member

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    Still, Clarity has less reserved capacity. And if count on loss, Prius would store only 5.5kWh on a 8.8kWh battery.

    But yes, Clarity has liquid cooled battery.
     
    #6 Roy2001, May 31, 2018
  7. triggerhappy007

    triggerhappy007 Active Member

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    I wouldn't worry you much about capacity loss in a PHEV, you will always have a backup compared to an EV. I'm sure Toyota designed this car better than the Leaf. You won't lose half your range after three years.
     
    #7 triggerhappy007, May 31, 2018
  8. Llamaguy

    Llamaguy New Member

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    I drove through the Honda lot when shopping and couldn't imagine seeing that eyesore every day. It positively makes the Gen 4 Prius look amazing in comparison.
     
    #8 Llamaguy, May 31, 2018
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