edatoakrun
Posts: 5222
Joined: Thu Nov 11, 2010 9:33 am
Delivery Date: 15 May 2011
Leaf Number: 2184
Location: Shasta County, North California

Re: LEAF Range and kWh use, at 45, 60 and 70 mph DOE tests

Thu Jan 28, 2016 1:38 pm

On-topic reply from another thread:

First highway trip - 2012 Leaf w/ 9 bars

http://www.mynissanleaf.com/viewtopic.php?f=31&t=21344
lpickup wrote:
drees wrote: 3.9mi/kWh looks low for ~60mph. I can usually get at least 4.2-4.3 at that speed on the highway.
Maybe in San Diego. At this time of the year (temps in the 30s/low 40s) I am thrilled to be getting 3.4 (albeit at 70mph on the highway) with 41psi in all tires. If my tires are down to 30-35psi, I get about 2.9 to 3.0 on the highway. I don't reach 4.2 territory until ideal temps in the late spring / early fall.
Sounds like both of you may be reporting a significant under-report error in your LEAFs' nominal kWh use reports, resulting in a corresponding over-report of m/kWh efficiency in your Dash/Nav screen/CarWings (NC) reports:

Actual LEAF efficiency in controlled constant-speed tests has been known since 2013, as posted on the first page of this thread:

60mph = 3.70mi/kWh

70mph = 2.92mi/kWh


http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf

I suggest both of you (and all other interested LEAF owners) try to quantify that kWh report error.

By doing so, you likely can estimate your LBC's corresponding error of reported capacity loss.

For comparison, I have estimated my 2011 is now under-reporting kWh use by close to 11%, meaning, if I could precisely replicate all of the efficiency factors of the AVTA 60 mph test , my nav screen would read ~4.1 m/kWh, and my Dash (which has an additional error factor, 2.5% under-report of miles driven) would read ~4.0 m/kWh.

But since I expect my LEAF's efficiency has increased since new, I would expect slightly higher efficiency than the AVTA found in a much-less-used LEAF, closer to the same (dash?) numbers you both reported above.

Because A LEAFs efficiency is not constant over time, and it is not possible to exactly replicate all the AVTA range test conditions, I suggest you will find it easier and get more accurate results by calculating the kWh report error from your LEAFs actual (from an external meter) and reported kWh use, rather than from the efficiency results from constant-speed tests.

Which is where I got the current ~11% under-report kWh error for my LEAF I mentioned above, evidently corresponding to my LEAF's ~11% LBC over-report error of capacity loss (currently 48.57 AHr, 73.31% remaining at 42+ k miles).

So, it looks like my LEAF's pack probably currently retains close to 84% of Nissan's rating of 24 kWh static capacity (~20.2 kWh).

My LBC should allow me to access ~90% (on average) of that, ~18.1 kWh actual (equivalent to~16.3 kWh nominal, as reported in m/kWh in my Dash/Nav screen/CarWings reports) when my pack is charged to "100%", and is warmed up to ~the AVTA test temperatures during both the charge and discharge cycles.

Both of your 60 mph m/kWh reports above indicate you might see similar results, if you care to look into it.
no condition is permanent

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