Mile/KWH Overly Generous

[zerooverdraft]

I guess the point of this post is what exactly does Nissan use to determine their Miles/KWH reading show on the dashboard instruments. The reason i ask this is because when I take a leaf spy reading before a trip, record the KWH available and then do it again after a trip, subtract the two from each other and then divide the trip miles by the KWH used, I never get an amount of Miles/KWH as high as the car's dashboard instruments get. In the winter its 2.9-4 miles/kwh and as it has gotten warmer its like 3.5-4.8 miles/kWH, but the car always shows higher, why is that?

 

[NeilBlanchard]

It could be any number of things: if your tires are worn, and/or if you have the Leaf S (which has smaller tires than the other models) then this would inflate the number of miles you actually traveled. The voltage of the battery pack changes from a full charge vs a low(er) charge.

 

[evnow]

2013 onwards they did something that shows much higher m/kWh than '11 did. There is an old thread I started on this somewhere ...

 

[dgpcolorado]

2013 onwards they did something that shows much higher m/kWh than '11 did. There is an old thread I started on this somewhere ...

Interesting; I don't recall seeing that. My 2012 miles/kWh numbers are quite consistent with my very accurate wall numbers. I just assumed that it was much the same for newer LEAFs.

 

[GerryAZ]

The actual wall-to-wheels numbers calculated from miles driven and kilowatt hours required to recharge for the 2011 and 2015 were/are consistently about 75% of the dashboard numbers (4.0 miles/kWh on dash with actual 3.0 miles/kWh from wall are typical numbers for my driving). Efficiency of the 2011 seemed to be dropping toward the end. It was not due to battery deterioration because I did not see a drop in efficiency on the original battery as it lost capacity. I had the wheel alignment checked and adjusted a couple months before the crash, but it did not seem to help. Unfortunately, I did not get a chance to investigate other causes.

Gerry

 

[NeilBlanchard]

On my most recent charge, I went 77.9 miles (corrected for odometer error) and it took 16.9kWh. That works out to 216.92Wh / mile, or 4.61 miles / kWh. The dash said 5.6 miles / kWh, so the difference is ~21.5%. Most of that - probably ~15%, is from losses in the wall-to-wheel process, though maybe these are higher?

On my e-Golf, the difference between the charge and the dash readout is ~15%, so that seems to be quite accurate.

 

[dgpcolorado]

The actual wall-to-wheels numbers calculated from miles driven and kilowatt hours required to recharge for the 2011 and 2015 were/are consistently about 75% of the dashboard numbers (4.0 miles/kWh on dash with actual 3.0 miles/kWh from wall are typical numbers for my driving)...

I have typically seen 88-90% when charging at 3.8 kW (without preheating, the numbers aren't relevant when doing that).

 

[billg]

On my most recent charge, I went 77.9 miles (corrected for odometer error) and it took 16.9kWh. That works out to 216.92Wh / mile, or 4.61 miles / kWh. The dash said 5.6 miles / kWh, so the difference is ~21.5%. Most of that - probably ~15%, is from losses in the wall-to-wheel process, though maybe these are higher?

Are you using the Level 1 EVSE that came with the LEAF and a Kill-A-Watt meter, or a Level 2 EVSE and a 240V meter of some sort?

Also, have you compared the kWh gain in the battery using LEAF Spy, compared to the kWh provided from the wall?

 

[Slow1]

On my most recent charge, I went 77.9 miles (corrected for odometer error) and it took 16.9kWh. That works out to 216.92Wh / mile, or 4.61 miles / kWh. The dash said 5.6 miles / kWh, so the difference is ~21.5%. Most of that - probably ~15%, is from losses in the wall-to-wheel process, though maybe these are higher?

Are you using the Level 1 EVSE that came with the LEAF and a Kill-A-Watt meter, or a Level 2 EVSE and a 240V meter of some sort?

Also, have you compared the kWh gain in the battery using LEAF Spy, compared to the kWh provided from the wall?

One has to be careful here on the "wall to wheels" comparisons as the rate of maximum charge will make a difference. There (from what I have read) is a required load for some pump(s)? that is a 'fixed' cost to charging. Thus the % number will get worse the slower the charge....

 

[NeilBlanchard]

On my most recent charge, I went 77.9 miles (corrected for odometer error) and it took 16.9kWh. That works out to 216.92Wh / mile, or 4.61 miles / kWh. The dash said 5.6 miles / kWh, so the difference is ~21.5%. Most of that - probably ~15%, is from losses in the wall-to-wheel process, though maybe these are higher?

Are you using the Level 1 EVSE that came with the LEAF and a Kill-A-Watt meter, or a Level 2 EVSE and a 240V meter of some sort?

Also, have you compared the kWh gain in the battery using LEAF Spy, compared to the kWh provided from the wall?

I am measuring the charge total with my EMW JuiceBox Premium. I do not have LeafSpy - does it work with the Leaf S?

 

[billg]

I do not have LeafSpy - does it work with the Leaf S?

Yes.

 

[NeilBlanchard]

Okay, does LeafSpy report a more accurate number? Is it a fixed ratio correction? Since I am not using the dash display except as a relative guide, and getting the actual consumption numbers from charges and corrected drive distances - does LeafSpy add anything to this?

 

[billg]

Okay, does LeafSpy report a more accurate number? Is it a fixed ratio correction? Since I am not using the dash display except as a relative guide, and getting the actual consumption numbers from charges and corrected drive distances - does LeafSpy add anything to this?

Well, it will give you a kWh reading, accurate to one decimal. If you take a reading before and after charging, it will tell you how many kWh you added during that charging session. Of course, it tells you lots more, too, most of which I don't understand. These screen shots from my Android phone were taken this morning.