Why can't I get 8.8kwh miles?

Discussion in 'Prime Main Forum (2017-Current)' started by SydneyNJ, May 30, 2019.

  1. ed4271

    ed4271 Member

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    The screenshots should answer your question to the total time yo charge. Screenshot_20190601-144056_ChargePoint.jpeg

    Posted via the PriusChat mobile app.
     
  2. ed4271

    ed4271 Member

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    This screenshot shows the actual time of charging. I don't take my my car off of charge. I just leave it plugged in. When I'm ready to leave I take it off. It does no harm. It just shows that you know that the amount of time the car has been plugged in not a total time of charging. Because send the app you can scroll along the timeline in the show Shield when it fully charged. And the time. But the screenshots answer your questions. Screenshot_20190601-144056_ChargePoint.jpeg

    Posted via the PriusChat mobile app.
     
  3. ed4271

    ed4271 Member

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    This should answer your question. Screenshot_20190601-144056_ChargePoint.jpeg

    Posted via the PriusChat mobile app.
     
  4. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    Gibberish aside, isn't there actually a potential issue with high currents and coiled power cables? In effect creating a transformer?
     
  5. fuzzy1

    fuzzy1 Senior Member

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    For single conductors, yes. The magnetic fields in adjacent coils add up.

    For double conductors, where the outgoing current in one conductor returns in the adjacent conductor, mostly cancelling out the magnetic fields, then (mostly) no.
     
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  6. Trollbait

    Trollbait It's a D&D thing

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    Mother-in-law had a space heater plugged into a long extension cord that shouldn't have been an issue, but its was coiled up.
    The cord was hot, and the plug and receptacle were scorched.
     
  7. fuzzy1

    fuzzy1 Senior Member

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    The cord was too small for the load, coiled or not.

    That said, coiling would have concentrated the heat more than if the cord was spread out. But the plug and receptacle would still have scorched, coiled or not.
     
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  8. SydneyNJ

    SydneyNJ Junior Member

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    So I ordered a multi-meter from amazon and did a test. My battery was almost empty (with only 1 mile left) on
    my MID. Plugged in my OEM charger last night. It told me it would take 5hr 10mins. I just left it overnight.
    Woke up this AM and checked. Attached are 2 pics. So you guys were right. The PRIME only let you charge
    ~75% of the 8.8kwh capactity (my car). The 25% is reserved for HV as some of you mentioned earlier.

    This test answers my original post. It costs me $0.11/kwh x 6.3kwh = 69 cents/charge. Not sure what the diff in
    amperage in the pictures mean. If I read this correctly, it draws 11.7A. I know L1
    draws 12A and L2 draws 16A. Not sure what the 0.024A is. Have to read it up.

    Btw, the Spartan is a pretty good meter for 17 bucks!
     

    Attached Files:

    #68 SydneyNJ, Jun 2, 2019
    Last edited: Jun 2, 2019
  9. jerrymildred

    jerrymildred Senior Member

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    Now you know we're not all spoofing you. LOL! Seriously, though, it really is nice to see for yourself. Glad you got the meter so you can actually see what's going on. (y)

    When the EVSE cable is plugged in to the wall outlet, there is an LED. It takes power to light it. My Duosaida L2 cable has several LEDs and draws even more vampire current than the stock EVSE, so I unplug it from the wall when not in use.
     
  10. SydneyNJ

    SydneyNJ Junior Member

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    Interesting.... is that really what that is? It actually separates the actual power consumption used by the car and exclude
    the LED power? That's pretty neat. I would have thought it would measure total power/amps flowing out of the outlet.

    Yeah... it's definitely nice to see the numbers myself. Thanks to you guys' ideas
     
  11. jerrymildred

    jerrymildred Senior Member

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    Of course it can't do that. I assumed that the 11.7A was while charging and the 0.024A one was after charging. The larger value is labeled "MAX" and the small one is unlabeled and therefore is the instantaneous value. That's how most meters work that store max/min readings.
     
  12. SydneyNJ

    SydneyNJ Junior Member

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    One thing I want to add about those two numbers in amps. If I press the "Display" button, it cycles through the various
    readings. The 0.024A showed up while the car was being charged not like my OEM charging cable was plugged into the outlet
    and the end was not plugged into the power inlet on the PRIME. So I keep pressing the "Display" button, these two numbers
    11.7A and 0.024A alternate.
     
  13. SydneyNJ

    SydneyNJ Junior Member

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    Maybe the 0.024A is what is required to power the Spartan meter! :)
     
  14. jerrymildred

    jerrymildred Senior Member

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    Nope.
     
  15. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    Just a nit on the capacity figures. I believe that full EV charge is about 85% state of charge. The HV SOC is about 18% to 23%, that is, in HV mode with an "empty" battery" the SOC varies between about 18% and 23%. 8.8kwh is the capacity of the battery. What you are measuring with the multimeter is what is coming in from the wall, not what is going into the battery. There are losses in the charger circuitry (such as in converting from 120VAC to around 400 Volts DC) and and in the battery chemistry of the charging process itself. So you are really charging the battery from around 23% to 85% (.62*8.8=5.46kwh). The rest (6.3-5.5 = 0.8) is dissipated as heat. When charging at 240V, we typically see around 6.0 kwh from the wall, due to charging at 240V being a bit more efficient.
     
    #75 CharlesH, Jun 2, 2019
    Last edited: Jun 2, 2019
  16. SydneyNJ

    SydneyNJ Junior Member

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    I was more interested in measuring my cost per charge. So the screenshots I uploaded show 6.3kwh was leaving the
    multi-meter into the charging cable. So I'm looking at this number as my Total Cost = 6.3kwh x $0.11/kwh = 69 cents.
    If what you're saying is true (I don't know the technical specs on this), then yes, maybe only 5.46kwh got transferred to
    the traction battery.
     
  17. jb in NE

    jb in NE Senior Member

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    I would be very surprised if there was a 0.9 KWh loss during the charge process. In any event, your math is correct - you pay for what comes out of the wall, not how much ends up in the battery. Note that if you have taxes applied on your electric bill, you will need to apply them in your calculation as well for the KWh you used.
     
  18. SydneyNJ

    SydneyNJ Junior Member

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    Yeah... there are taxes that need to be part of the equation. In fact, I pay delivery charges as well. Now, that you're
    bring this up and I'm thinking a bit more, it isn't 69 cents any more. Hopefully, after adding these other variables, it won't
    be equivalent to $2.69/gal for 55 miles. Has anyone actually calculated or come up with a rough estimates of how much
    you are actually paying for 1 mile using electric?
     
  19. Salamander_King

    Salamander_King Senior Member

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    A full charge of ~6kWh from the wall drive ~25-35 miles of EV range. So you can calculate how much it cost per mile. Rule of the thumb is if the half the cost of a gallon of gas you can by in your local is more than what you pay for a full charge, you will be saving by driving EV.
     
  20. jb in NE

    jb in NE Senior Member

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    For me, winter is 1 cent per mile and summer is 2 cents per mile on EV from wall.
     
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