14.7 kw hour full charge?

Discussion in 'Honda' started by Scottacus, Mar 26, 2018.

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  1. Scottacus

    Scottacus New Member

    I drove the vehicle to zero miles ev yesterday as I pulled into the garage and plugged it in for an overnight charge at 220v 32A on my JuiceBox and this morning the JuiceBox app says the 14.7 kw hrs have been added to the vehicle with 41 miles of charge. My Clarity has never shown 48 miles of EV range when fully charged and the best I've seen is about 43 miles of EV range on a full charge. I called the dealership and they are looking into this but they have zero Clarity experience. Anyone else have this issue? Is the 30 degree F temp a factor for charging?

    Thanks to anyone who can shed light on this issue!
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  3. jdonalds

    jdonalds Well-Known Member

    There are two things you can do to raise the ev range estimate.

    1) wait for warmer weather
    2) drive as efficiently as you can.
    DaleL, Domenick and KentuckyKen like this.
  4. Scottacus

    Scottacus New Member

    Yes thanks! I can start out with 42 miles of EV range and end a four mile trip with 40 miles of EV range but what about the vehicle not accepting a full 17 kWh as per the spec sheet? If the battery was fully discharged shouldn't it fill fully and shouldn't that be 17 kWh?
  5. jdonalds

    jdonalds Well-Known Member

    Common thinking is to protect the battery it is never allowed to fully charge or discharge. So about 14kw is the portion we get to use of the 17kw battery.

    This is the same for all battery electric cars.
    Last edited: Mar 26, 2018
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  6. Scottacus

    Scottacus New Member

    Excellent, that is what I was hoping the answer was going to be! I know that battery charge and discharge are effected by temperature. That is why I included the 30F in my initial post wondering if temp was a factor.
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  8. bfd

    bfd Active Member

    Next time you're at "zero" note that your battery gauge still shows two pips. It never goes completely empty. The HV side of the operation needs battery power. So the system will keep the battery in a charged (though at a very low %) state even when the EV side says zero. If instead you opt to charge the battery when it's at that "zero" state, you can tap twice on the HV button and the ICE will charge it up. (But you may not enjoy the noise).

    In three months, my highest charge level is 14.818 kWh.

    And yes, 30ºF ambient is definitely a factor. Even the few days that we dipped into the 50ºs, my range went down about 10%. But most of the time, in the 60ºs-70ºs so far this late winter/early spring, the range has been steadily in the high 40s - low 50s. The actual EV miles pretty closely follow the estimates. I've been surprised about that.
    Last edited: Mar 26, 2018
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  9. Scottacus

    Scottacus New Member

    Thanks for the replies, this is what eMotorwerks said

    Thanks for contacting us. Currently the Juice box and the car don't communicate a lot of information. the car tells the charger I need energy and the charger gives it until the car tells it to stop or the time of use setting overrides it. The App will only show what was added to the car. The range varies. I have the Honda Clarity full electric version, my range on a "full charge" per spec is 89 miles. I have seen it as low as 67 and as high as 115, it mostly depends on your last trip. the good rule of thumb If the car shows full then it is.
    The EV range may show 0 because you have used the "usable" capacity of the battery which is different the the rated capacity so that the battery doesn't get fully discharged so that the car works properly and the battery lasts longer, think of if you let you phone drain until it turns off it takes longer to restart. Sorry that was a lot of information. If you need more clarity on a topic here please let me know. ( Pun intended )
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  10. I believe we are only using about 12-12.5k. While the charger shows 14.5 the chargers are 80-85% efficient. Not using the entire capacity it what extends the life of the battery. The outside temp changes the efficiency of the battery. Warmer temps will show greater range. Driving using braking also can yield higher mileage than straight highway. It's just the nature of batteries. Just pay attention and you'll learn. Have fun playing the game.
    CaryLyn, Vezz66, JyChevyVolt and 2 others like this.
  11. Roy2001

    Roy2001 Member

    Surprised that it charges 14.7kWh while the battery capacity is 17kWh. That is using 85% of the capacity, and only reserve 15% which is quite low.

    Reserve 30+% vs 15% of capacity could increase the charge cycle by 10x.
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  13. Viking79

    Viking79 Well-Known Member

    As already pointed out, charging is not 100% efficient, so 14.x kWh from the wall is around 12 or 12.5 kWh used from the battery meaning they are only using around 75% of usable capacity .
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  14. Roy2001

    Roy2001 Member

    MPGe is determined by total amount of electricity draw from the wall outlet, not the amount stored in the battery.

    If it is 14.7Kwh, then based on EPA 47 miles rating, the MPGe is 107.75, which is pretty close to EPA 110 MPGe rating. Of course YMMV, but 15% reserved capacity sounds too little to me. My Prius Prime draws 6.3Kwh each charge for 8.8Kwh battery.
  15. While you’re correct that it’s included in the rating is not utilized for the determining the capacity of the battery used. It has nearly a 30% capacity. .
  16. Roy2001

    Roy2001 Member

    with more than 2Kwh loss? Not possible!
  17. ok.... so here we go. I even sourced the results of a study for you.



    On aggregate, Level 2 charging was confirmed to be 2.7% more efficient than Level 1 charging. A mean charge efficiency of 86.4% was observed in Level 2 charge events and Level 1 charge events were shown to be 83.7% efficient on average.

    Now let's break out the Casio wristwatch calculator.
    14.7kw charge from outlet yields 12.7kw at the higher 86.4% efficiency. That is clearly a 2kw LOSS. Not just possible, but fact.

    Now that I've let my sore fingertips rest from the tiny buttons we'll take that 17kw divided into the 12.7kw yield and they gives you 75%. So roughly 25%. You can review previous and while we were spit balling, Viking79 and I are spot on. It's not 15%.
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  18. Roy2001

    Roy2001 Member

    If the efficiency is around 85% means you only use the 85% of the capacity, then why GM/Toyota need to reserve 30% of the capacity?

    And if that is true, then why full recycle should be much more than 500 for smart phone battery right?
  19. The difference between 25 to 30 is a diffence in technique and design benefit. Differences is allowable discharge, max draw, weight, mileage. It's all different and what they are willing to warranty.

    Whatever your question is regarding a smart phone has no relevance. They simply are not the same.
  20. spaj223

    spaj223 New Member

    The built in AC to DC converter will lost some enargy too.
  21. CaryLyn

    CaryLyn New Member

    This is a newbie question. How do you determine how many kWt the car is charged each night? On the Honda app or in the car? Or is it something your charger records? I’m charging each night with a 110.
  22. My 220v chargers have usage meters. On 120v you might be able to get a usage meter but it would need to be able handle the amps you're pulling.
  23. CaryLyn

    CaryLyn New Member


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