Have you measured the actual efficiency?

RedStallion

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I have a Splitvolt device that among other things counting kWh I consumed charging car from the moment of installation. So dividing the total mileage on the car to the total energy consumed from the grid I'm getting about 2.5 miles per kWh.
At the same time the "Trip1" display, which I haven't reset from the time I started driving shows the average of 3.3 mi/kWh. If both numbers are correct, the grid-to-wheels efficiency is only about 75%. Or putting it another way, 25% of electricity is wasted.
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timbop

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Did you have it plugged in during the cold weather to condition the car and battery without actually adding miles?
 

DBC

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No, the numbers reflect the driving, there aren't any known losses.
He's asking about whether there are reasons for the charging efficiency -- related to losses from wall to battery -- to be so low. These losses should be more around 10% not 25%. Could be the Splitvolt. Would not entirely surprise me.
 
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Murse-In-Airy

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I think the bigger question is how many kWh does the split volt say it’s given the car, versus how many kWh has actually reached the battery. Your 3.3 miles/kWh is actually pretty good but reflects more about your driving style than the efficiency of your car.
 


ab13

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The L2 (and any) charging has losses. Around 5-10% depending on equipment, etc...
 

benk016

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Don't forget, not all of the power you use to drive comes from charging. You also recharge the battery every time you slow down and stop.
 
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RedStallion

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The L2 (and any) charging has losses. Around 5-10% depending on equipment, etc...
I measured about 5% loss is in total home circuit. The charger itself barely consumes anything, it doesn't even get warm. I'm using Grizzl-e, it has very thick cable, probably rated for 100A, doesn't get warm at all.
I don't know how much the car itself is losing during charging, but I doubt it's 20%. We have about 25% in total to account for.
I haven't used DC charging yet, I wonder if there is a discrepancy between the charger reported kWh and SOS reported by car.
Another thing not totally clear is the 3.3mi/kWh reported by car. We don't know how that number is calculated. Does kWh number correspond to SOS change or measured consumption. There is another loss, perhaps 5% or more when battery is discharging, depending on current. If they measure the power delivered then the battery lost more than that, but then there would be a noticeable discrepancy in actual mileage and calculated from the reported consumption number.
 
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ab13

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I measured about 5% loss is in total home circuit. The charger itself barely consumes anything, it doesn't even get warm. I'm using Grizzl-e, it has very thick cable, probably rated for 100A, doesn't get warm at all.
I don't know how much the car itself is losing during charging, but I doubt it's 20%. We have about 25% in total to account for.
Just to be clear, the charger for L2 is in the car, the EVSE is a "smart" switch.
 

Woeo

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Your 3.3 miles/kWh is actually pretty good but reflects more about your driving style than the efficiency of your car.
Nothing to do with the efficiency of the car. Except it is the efficiency of his car.
 
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Woeo

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The L2 (and any) charging has losses. Around 5-10% depending on equipment, etc...
EPA MPGe is a measure of the efficiency including grid loss.
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