2013-2014 bar losers and capacity losses

[dhanson865]

well now you have to cite the 2011-12 that went 100,000 miles ANYWHERE with all 12 bars before we can continue this discussion and keep in mind; my statement should include most of the 2013's but I think I have made that clear enough

FYI; Steve Marsh was a 3 bar loser when he hit 100,000 miles on his 2011

I edited that before you submitted your reply. I can't easily check the wiki from work but I pulled it up on the cell and changed it to reflect reality.

 

[asimba2]

Hot climate; Sacramento, CA. 2013 car.

I am new to leafspy and not sure how this compares to other cars.

 

[edatoakrun]

Hot climate; Sacramento, CA. 2013 car...

What's your LEAF's (on the driver's door jamb) build date?

 

[dhanson865]

Hot climate; Sacramento, CA. 2013 car.

What is the manufacturing date? Looks like you still have 12 bars but I'm not sure if it saw time in summer 2013 or if 2014 was it's first summer.

 

[asimba2]

Build date is 10/13, I leased mid-January. I was surprised to see 2 QC sessions, none of which were mine, so this car probably baked in the sun on a full QC charge for the first 3 months of its life.

My readings are worse than the 100k mile Leaf taxi in UK.

 

[DaveinOlyWA]

Build date is 10/13, I leased mid-January. I was surprised to see 2 QC sessions, none of which were mine, so this car probably baked in the sun on a full QC charge for the first 3 months of its life.

My readings are worse than the 100k mile Leaf taxi in UK.

ya your numbers really suck. the QC is likely from the dealer which is the norm when they sell them. my numbers are way over yours and mine was built a month later

 

[edatoakrun]

Build date is 10/13, I leased mid-January. I was surprised to see 2 QC sessions, none of which were mine, so this car probably baked in the sun on a full QC charge for the first 3 months of its life.

My readings are worse than the 100k mile Leaf taxi in UK.

And not much higher than what I saw at ~18k miles and ~26 months, in a similar climate, as posted here:

="edatoakrun" Posted: Thu May 16, 2013 9:01 am...My capacity reports at app-reported temps from ~59 f to ~86 F are extremely consistent, varying only ~0.20 % since the first capacity report I got at the SF BayLEAFs meeting over a month ago. Most recently:



That being said, I think they are consistently wrong, in showing an ~12.5% loss of capacity, which has not shown up in my LEAF by either recharge or range capacity tests.

What I have seen that has surprised me is that there is only a rough correspondence between...the nav screen m/kWh and dash m/kWh reports...and that reported by the app...

http://www.mynissanleaf.com/viewtopic.php?f=44&t=12789" onclick="window.open(this.href);return false;

Go to the thread for more details.

FYI, ~25 months and ~19k miles after that post, it appears my 2011's current capacity in charge accepted from the meter to "100%" is now down ~13% from "new" (as compared to that accepted by a 23.4 kWh static capacity pack, the average reported from AVTA tests of 2011 LEAFs) and my LBC AHr report on 6/8/15 was 50.48 (76.19%).

And not very long after that post, I learned to disregard the app (LBC) reports of kWh use/available capacity remaining, as it was clear the the nav screen m/kWh and dash m/kWh reports are far more usefully consistent.

 

[dhanson865]

as a reminder the 4 bar losers in the wiki are

AZ x11 (out to 45 months)
CA x10 (out to 48 months)
TX x4 (out to 52 months)
FL
unknown
WA

and the 3 bar losers are

AZ x21 (out to 28 months)
CA x7 (out to 36 months)
TX x6 (out to 40 months)
FL x3 (out to 30 months)

Just updated the wiki again. Bars dropping like flies on the early Leafs this summer. It'll be interesting to see if any more 2013s join the fray before the end of the year.

As a reminder we have 3 in the wiki that are known 2013 Leafs with 1 bar lost and I'm expecting LEAFfan's to drop that 2nd bar one of these days (it does seem the battery values are different on 2013 Leafs).

#175 May 26 2015 RLewisCA San Dimas, CA 23,996 miles 26 months 01/13 2013 Model Year 401841 http://www.mynissanleaf.com/viewtopic.php?f=30&t=19667&start=10#p425287" onclick="window.open(this.href);return false;

#172 March 2014 hhgblueleaf Plano, Texas 4,000 miles 9 months 05/13 2013 Model Year 411131 http://www.mynissanleaf.com/viewtopic.php?f=30&t=16467" onclick="window.open(this.href);return false;

#173 November 2013 LEAFfan Pheonix, AZ 8,000 miles 10 months 01/13 2013 Model Year VIN unknown http://www.mynissanleaf.com/viewtopic.php?f=30&t=16467&start=20#p370953" onclick="window.open(this.href);return false;

 

[asimba2]

That being said, I think they are consistently wrong, in showing an ~12.5% loss of capacity, which has not shown up in my LEAF by either recharge or range capacity tests.

I just want to confirm I understand what you are saying. Leafspy shows a 12.5% capacity loss but 2 other tests (wall input & range test) shows less? That's kind of where I'm at. I keep track of what percentage of the battery it takes on certain routine trips. Even though Leafspy is showing 11% capacity loss, I have noticed no degradation in driving range. Tell me if my method is somehow meaningless--using the dash display for SOC in %, I know that when my car was new it would charge to 80% and I almost always had 55% left in the battery when I arrived home. Fast forward to today and I still arrive home with 55% of the battery remaining. I would expect it to take 11% more battery if that amount of degradation had occurred. Yes?

The only sign of degradation I have seen is the car charges to 79% now instead of 80% and LBW comes on at 19% rather than 18% when new.

 

[Valdemar]

That being said, I think they are consistently wrong, in showing an ~12.5% loss of capacity, which has not shown up in my LEAF by either recharge or range capacity tests.

I just want to confirm I understand what you are saying. Leafspy shows a 12.5% capacity loss but 2 other tests (wall input & range test) shows less? That's kind of where I'm at. I keep track of what percentage of the battery it takes on certain routine trips. Even though Leafspy is showing 11% capacity loss, I have noticed no degradation in driving range. Tell me if my method is somehow meaningless--using the dash display for SOC in %, I know that when my car was new it would charge to 80% and I almost always had 55% left in the battery when I arrived home. Fast forward to today and I still arrive home with 55% of the battery remaining. I would expect it to take 11% more battery if that amount of degradation had occurred. Yes?

The only sign of degradation I have seen is the car charges to 79% now instead of 80% and LBW comes on at 19% rather than 18% when new.

It is possible you drive more efficiently now. These kind of observations are not very useful if you're not tracking your miles/kwh.

 

[cwerdna]

Build date is 10/13, I leased mid-January. I was surprised to see 2 QC sessions, none of which were mine, so this car probably baked in the sun on a full QC charge for the first 3 months of its life.

My readings are worse than the 100k mile Leaf taxi in UK.

ya your numbers really suck. the QC is likely from the dealer which is the norm when they sell them. my numbers are way over yours and mine was built a month later

Well, asimba2 lives in a MUCH hotter climate than you, Dave.

Just looking at the Google Weather forecast for Sacramento shows these highs for the next week, starting w/Friday: 95 F, 96, 90, 89, 91, 93, 97, 97.

 

[edatoakrun]

="asimba2"

That being said, I think they are consistently wrong, in showing an ~12.5% loss of capacity, which has not shown up in my LEAF by either recharge or range capacity tests.

="asimba2" I just want to confirm I understand what you are saying. Leafspy shows a 12.5% capacity loss but 2 other tests (wall input & range test) shows less?...

Correct, but you are quoting results from over two years ago, when it was already obvious I probably had a significantly higher % of "new" capacity than my LEAF's LBC was reporting, but it was not possible yet for me to accurately estimate my actual loss of capacity.

="asimba2"...That's kind of where I'm at. I keep track of what percentage of the battery it takes on certain routine trips. Even though Leafspy is showing 11% capacity loss, I have noticed no degradation in driving range...

I experienced no significant range loss in my driving (which is at lower speeds and with far more ascent and descent than for most) until I replaced my tires in July 2014 at ~29 k miles. My current range loss is much lower than my estimate of capacity loss (~13%, as per previous post) and I think that suggests that my 2014 ecopias have lower rolling resistance than my 2011 tires did, at equivalent levels of wear.

Vehicle efficiency is not constant over time, especially at lower speeds (and unless carefully normalized, neither is driver efficiency) so range tests have not been as useful for me as I initially expected, to determine my pack's relatively small decrease in battery capacity.

="asimba2"...Tell me if my method is somehow meaningless--using the dash display for SOC in %, I know that when my car was new it would charge to 80% and I almost always had 55% left in the battery when I arrived home. Fast forward to today and I still arrive home with 55% of the battery remaining. I would expect it to take 11% more battery if that amount of degradation had occurred. Yes?...

My 2011 does not have a dash SOC display, but it sounds like (from reading others' posts) that that display (like my 2011's dash charge bars) may be informed by the LBC's gid count, so all my comments from here on should be checked to see if they also hold true for 2013-on LEAFs.

As I mentioned previously, I never rely on the LBC as an indicator of kWh use or remaining battery capacity.

When I compare the nominal kWh use reported by my nav screen as I drive, (2011-12 LEAF dash m/kWh has the ~2.5% underreport error in miles driven as is reported by Carwings, which is why 2011-12 LEAF owners should never use dash m/kWh without correction) to the LBC reports it is obvious that gids contain such variable nominal Wh content (I've seen from ~ 40 nominal Wh to ~100 nominal Wh per gid, over ~ 20 miles of driving) that LBC reports are not useful for accurately calculating current capacity, or range remaining.

The only consistency I've seen in gid/nominal Wh content, is that the LBC always over-reports nominal kWh use at the top of the charge, and under-reports it for energy discharges from lower SOC.

In other words, from my LEAFs LBC reports, gids always have contained more nominal Wh when from lower SOC, than they do at higher SOC, when I have measured various segments of my available charge capacity using range/capacity tests.

So, if Nissan's engineers intended gids to be a display of units with constant Wh content, they failed, at least in my LEAF.

But quite possibly (IMO) at least some of the wh/gid variability was intentional, and just another means by which Nissan sought to fool the driver into avoiding excessive relience on the bottom of the pack.

Another suggestion that wh/gid variability may be intentional, is in how it seems to vary ~consistently with certain driving conditions.

I've only seen very low Wh/gid from the LBC at the start of trips beginning with large descents, resulting in unsustainable (but mathematically correct) double-digit m/kWh nav screen reports.

It seems likely to me that Nissan engineers did not want external energy sources such as energy from descent (or maybe even a high-speed tailwind...) to be accurately represented in the LEAF's dash capacity bar display, lest the driver get unreasonable expectations of future range remaining.

Now, as to nominal kWh use reported by my 2011's dash, nav screen and Carwings reports, I have never been able to detect any variation in Wh content over a single charge cycle with a range or recharge capacity test. I expect there are errors in the reports, but they are just not large enough for me to see over the other noise in every range/capacity test.

However, while my LEAF's nominal kWh use reports are reliably constant in Wh content over a single charge, and over subsequent discharge cycles in the short-term, there definitely seems to have been a change in Wh content/nominal kW over time, which can be observed by my LEAFs decrease in reported charging efficiency, which can be observed by comparing the use reported by a meter before your EVSE, to the nominal kWh use as reported by your LEAF.

When my LEAF was new, each nominal kW (reported on dash, nav screen and CW energy report) actually held fairly close to 1,000 Wh, as I saw from my first range/capacity test:

My earliest range test, on a hot Summer afternoon:

On 9/7/11.... When I reached my driveway, at 87 miles, I still had (less than) one bar, so I drove until I got the "very low battery" warning and simultaneously lost the last bar, at 91.5 miles. I got home with 93.4 miles, and between 5,500 and 6,000 ft. of ascent and descent, at an average speed of about 40 mph (those last 6.4 miles were up and down a hill at low speed). Since the last 1.9 miles after the "very low battery” warning were at about 20 mph and required about 150 ft. net descent with regen, I was probably still very close to the VLBW point capacity, when I parked.

According to CW, on this drive I used 18.7 kWh to drive 91.1 miles at average energy economy of 4.9 m/kWh.

I rechecked 2 other recent drives of 85-105 miles and each time CW has erred, under-reporting distance traveled, as compared with both my odometer and Google Maps, by 2.5%, +/- 0.1%.

Extrapolating from the chart, it appears CW may be saying the 1.7 kWh (8.5% from the chart, of 20.4 total kWh-anyone have a better number?) I had left at or near VLBW implies total available battery capacity of about 20.4 kWh...

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064" onclick="window.open(this.href);return false;

The most significant correction I'd make today, is that I have since range-tested the capacity from VLBW to turtle (but coarsely, and only once) and that seems to be closer to ~2.0 nominal kWh, so I probably had ~20.7 nominal kWh available to turtle, on that day almost four years ago, and to reiterate, each of those nominal kW probably represented fairly close to 1,000 actual Wh, at that time.

Almost four years later, the same dash, nav screen and CW energy reports from range/capacity tests driven on ~the same route now seem to be reporting (as best I can estimate) ~11% error, each nominal kWh now actually containing ~1,110 Wh, per kW from the meter (as reduced by the cycling efficiency shown by AVTA testing) and ~the same error shown by my LBC, over-reporting ~24% capacity loss, rather than what I believe most likely to be ~13% actual capacity loss from new.

That's ~13% down from the ~23.4 kWh average reported for 2011 LEAF packs tested by the AVTA, and more like ~15.5% down from the 24kWh spec.

This all assumes constant charge/discharge efficiency over time, which is another variable, a reduction in which probably means my actual capacity loss is slightly beyond ~13%.

But very unlikely, IMO, that cycling efficiency has decreased by ~11%, which would require explaining why my battery doesn't seem to be heating up much more than when new, during the charge/discharge cycle, and why my 10-bar-battery LEAF, on a warm day on a slow-speed route, still covers 100+ miles, in range/capacity tests, using only the ~87% (currently) of my total charge available, from "100%" to VLBW.

 

[asimba2]

Well, asimba2 lives in a MUCH hotter climate than you, Dave.

My pack temperature is 94 degrees right now and I have not even driven the car today, other than moving it 20 feet to a shady place in the late afternoon. 1-2 hours after moving the car to the shade Leafspy was showing a temperature 3 degrees higher than when it was in the sun.

Still showing 6 temperature bars on the dash. It's sitting at 7 for at least half the summer.

 

[DaveinOlyWA]

Just now hitting 23,500 miles and changes from new

ahr; 67.36 to 62.70ish
Kwh available; 22.7 to 21.0
Hx; 105ish to 96
SOH 100 to 95

Never did do a proper range test. Essentially too busy for that. But did go over 100 miles a few times including a 105.2 mile trip with 9 left on GOM.

As far as what it does now? Last week did one trip of 92.9 (don't remember what GOM had. it was like 12-15 or so I think) and one of 97.9 and got to LBW just before end of day on that one.

 

[GRA]

So, if I've done my sums correctly you're down about 7.5% in kWh (21/22.7) after 18 months and one PNW summer?

 

[DaveinOlyWA]

So, if I've done my sums correctly you're down about 7.5% in kWh (21/22.7) after 18 months and one PNW summer?

ya, there abouts. the numbers published are a mean average. kwh available along with GIDs are only available when I do a complete charge which lately has only been 3-4 days a week. so I take the last 5 readings and divide by 5 so the number is an average. the range on ahr is not a lot .4-.5 ahr. the rest of the numbers vary quite a bit. My low water GID mark was actually 258 but the more realistic average is 273-274.

 

[edatoakrun]

Forgotten (by me) comments by Andy Palmer on this video from 10/12 posted recently on a other thread may help answer the questions I asked below (page 4) re both real battery improvements from 2011 to 2013 MY, and how the 2011-12 LEAF's dash capacity bar "pessimistic gauge" (gid report) error has been changed in 2013- on LEAFs.

https://www.youtube.com/watch?v=R1tfX7fRWPI

~ 5 minutes :

"...the reality is that that meter (2011-12 dash capacity bars) reads pessimistically..."

~11 to 12 minutes:

(only) "...small improvements... (made in the 2013 battery)...evolution, not revolution...but gauge accuracy is addressed..."

It's certainly possible that 2013's do have accurate LBC reports (neither optimistic or pessimistic) but I suggest any 2013-on LEAF owner check their battery capacity for themselves, rather than rely on the LBC (gid) report, just as should 2011-12 LEAF owners.

If you remain complacent about your capacity loss, due to your relatively high gid/capacity bar retention, you may just be repeating the mistakes of 2011-12 LEAF owners, whose "pessimistic" gid readings/capacity bar losses drove some of them to hysteria.

BTW, my estimate for my 2011 is that actual loss of capacity from delivery in mid-May 2015, after driving for ~four years and ~36,000 miles in a warm climate, was probably ~12.5% (from ~23.4 initial static kWh) while my LBC reported gid loss at the same date of ~23%.

I suggest, again, that anyone trying to monitor the actual battery capacity loss, of any LEAF from any MY, DO NOT rely on the LBC.

It is becoming clear that either there was a dramatic improvement in battery design ~with the 2013 MY, or (far more likely, IMO) the LBC was simply altered to report higher gids, and fewer capacity bar losses.

I wonder how long after (or before?) Andy Palmer was harangued by irate-gid-meter-wielding-LEAF-drivers in Phoenix in 2012, that the changes were made?

Given the performance noted below, You have to wonder if the Pessimistic Gauges, may now be overly optimistic...

Busy Wizzy Hits 100,000 Mile Landmark

The Nissan LEAF that sparked an electric taxi revolution in Cornwall has clocked up its 100,000th mile without losing a single bar of battery life*...

http://www.newsroom.nissan-europe.com/uk/en-gb/Media/Media.aspx?mediaid=132843"

 

[dhanson865]

I suggest any 2013-on LEAF owner check their battery capacity for themselves, rather than rely on the LBC (gid) report, just as should 2011-12 LEAF owners.

...

BTW, my estimate for my 2011 is that actual loss of capacity from delivery in mid-May 2015, after driving for ~four years and ~36,000 miles in a warm climate, was probably ~12.5% (from ~23.4 initial static kWh) while my LBC reported gid loss at the same date of ~23%.

And how do you propose people check the capacity? You put a heck of a lot of text there and never specified a method.

 

[edatoakrun]

I suggest any 2013-on LEAF owner check their battery capacity for themselves, rather than rely on the LBC (gid) report, just as should 2011-12 LEAF owners.

...

BTW, my estimate for my 2011 is that actual loss of capacity from delivery in mid-May 2015, after driving for ~four years and ~36,000 miles in a warm climate, was probably ~12.5% (from ~23.4 initial static kWh) while my LBC reported gid loss at the same date of ~23%.

And how do you propose people check the capacity? You put a heck of a lot of text there and never specified a method.

There are multiple methods, as posted on other range test/recharge test threads, but all have limitations.

You can never view your pack's actual static capacity (without removing the battery and having a qualified lab test it) so you can only estimate capacity from range tests or recharge capacity, and rely on the AVTA results to determine how your available capacity, corresponds to static, as determined by the AVTA tests.

There is considerable variation in the percentage of capacity the LBC allows you to access between "100%" and the lower SOC's, LBW, VLBW, turtle and shutdown, in repeated cycles, so you would want to try to use the largest sample of charge cycles as possible.

The most accurate method, IMO, would be to discharge to the lowest SOC allowed, and meter the recharge to "100%" multiple times over a short interval.

Since it isn't practical for me to fully discharge and monitor the recharge multiple times each month, about a year ago I started to monitor the nominal efficiency of that charge cycle I use the most, from "80%" to ~LBW (and sometimes almost to VLBW in the Winter) which is what I use to make the 50-55 mile trip to the Sacramento Valley floor and back, usually ~ ten times per month.

I use the dash, nav screen and CW energy reports to estimate the nominal kWh error, by finding the nominal discharge/charge cycle efficiency error, which seem to be confirmed by individual range tests:

As I posted in mid-June higher up on this page:

...Almost four years later, the same dash, nav screen and CW energy reports from range/capacity tests driven on ~the same route now seem to be reporting (as best I can estimate) ~11% error, each nominal kWh now actually containing ~1,110 Wh, per kW from the meter (as reduced by the cycling efficiency shown by AVTA testing) and ~the same error shown by my LBC, over-reporting ~24% capacity loss, rather than what I believe most likely to be ~13% actual capacity loss from new.

That's ~13% down from the ~23.4 kWh average reported for 2011 LEAF packs tested by the AVTA, and more like ~15.5% down from the
24kWh spec...

The nominal kwh use (dash and Nav screen m/kWh) for my six trips "80%" to ~ LBW in June 15 totaled 51.6 nominal kWh (from CarWings daily use reports) while the six recharges back up to "80%" required ~65.2 kWh from the meter, a nominal cycling efficiency of ~79.0%.

Nominal cycling efficiency of only~79.0% (L2, 16 amp, ~240 V) is improbable, IMO,.

As was my LEAF's nominal 6.4 m/kWh overall last month, reflecting the same ~11% under-report of kWh use, meaning my actual average driving efficiency for the month was likely ~ 5.9 m/kWh, dash m/kWh and CarWings both having the same ~2.5% under-report of miles driven, partially offsetting the common ~11% under-report of kWh use.

So I believe my LEAF instead probably used ~57.3 actual kWh (51.6 X 1.11 nominal kWh error) last June which would imply actual cycling efficiency of ~87.7%.

I suspect that calculated ~87.7%. efficiency might be slightly high.

As another example, May 2015 results produce a ~86.9 % cycle efficiency using a ~10.5% wh/kWh correction, and the same methodology.

But it was a very warm June, and my battery was on average, probably warmer than that used in any of the AVTA tests (which only have reported the lower cycling efficiency from below-turtle to "100%" charge cycles).

If you have a significant seasonal change in ambient temperatures, the increase in charging efficiency in warmer weather (less of the Wh from the wall is used to warm the battery while charging) is easy to observe.

So I would expect my warmer battery in June to have had relatively high cycling efficiency, both nominal and real.

For as long as I have been watching my packs gid numbers since ~March 2013 (with the exception being during the 3227 update wild-gid-chase) the gid loss has closely matched the nominal kWh loss, so I think it's very likely the actual loss of available capacity is probably close to 13% (to date) as shown by both, after correcting for the common ~11% (as of this date) error.

And, unless evidence shows up indicating otherwise, I think the loss of average available capacity of my pack, probably comes close to reflecting the actual capacity loss of my battery pack, as it seems to have for the LEAFs in the various AVTA reports.

 

[dhanson865]

I suggest any 2013-on LEAF owner check their battery capacity for themselves, rather than rely on the LBC (gid) report, just as should 2011-12 LEAF owners.

...

BTW, my estimate for my 2011 is that actual loss of capacity from delivery in mid-May 2015, after driving for ~four years and ~36,000 miles in a warm climate, was probably ~12.5% (from ~23.4 initial static kWh) while my LBC reported gid loss at the same date of ~23%.

And how do you propose people check the capacity? You put a heck of a lot of text there and never specified a method.

There are multiple methods, as posted on other range test/recharge test threads, but all have limitations.

You can never view your pack's actual static capacity (without removing the battery and having a qualified lab test it) so you can only estimate capacity from range tests or recharge capacity, and rely on the AVTA results to determine how your available capacity, corresponds to static, as determined by the AVTA tests.

There is considerable variation in the percentage of capacity the LBC allows you to access between "100%" and the lower SOC's, LBW, VLBW, turtle and shutdown, in repeated cycles, so you would want to try to use the largest sample of charge cycles as possible.

The most accurate method, IMO, would be to discharge to the lowest SOC allowed, and meter the recharge to100% multiple times over a short interval.

Since it isn't practical for me to fully discharge and monitor the recharge multiple times each month, About a year ago I started to monitor the nominal efficiency of that charge cycle I use the most, from "80%" to ~LBW (and sometimes almost to VLBW in the Winter) which is what I use to make the 50-55 mile trip to the Sacramento Valley floor and back, usually ~ ten times per month.

I use the dash, nav screen and CW energy reports to estimate the nominal kWh error, by finding the nominal discharge/charge cycle efficiency error, which seem to be confirmed by individual range tests:

As I posted in mid-June higher up on this page:

...Almost four years later, the same dash, nav screen and CW energy reports from range/capacity tests driven on ~the same route now seem to be reporting (as best I can estimate) ~11% error, each nominal kWh now actually containing ~1,110 Wh, per kW from the meter (as reduced by the cycling efficiency shown by AVTA testing) and ~the same error shown by my LBC, over-reporting ~24% capacity loss, rather than what I believe most likely to be ~13% actual capacity loss from new.

That's ~13% down from the ~23.4 kWh average reported for 2011 LEAF packs tested by the AVTA, and more like ~15.5% down from the
24kWh spec...

The nominal kwh use (dash and Nav screen m/kWh) for my six trips "80%" to ~ LBW in June 15 totaled 51.6 nominal kWh (from CarWings daily use reports) while the six recharges back up to "80%" required ~65.2 kWh from the meter, a nominal cycling efficiency of ~79.0%.

Nominal cycling efficiency of only~79.0% (L2, 16 amp, ~240 V) is improbable, IMO,.

As was my LEAF's nominal 6.4 m/kWh overall last month, reflecting the same ~11% under-report of kWh use, meaning my actual average driving efficiency for the month was likely ~ 5.9 m/kWh, dash m/kWh and CarWings both having the same ~2.5% under-report of miles driven, partially offsetting the common ~11% under-report of kWh use.

So I believe my LEAF instead probably used ~57.3 actual kWh (51.6 X 1.11 nominal kWh error) last June which would imply actual cycling efficiency of ~87.7%.

I suspect that calculated ~87.7%. efficiency might be slightly high.

As another example, May 2015 results produce a ~86.9 % cycle efficiency using a ~10.5% wh/kWh correction, and the same methodology.

But it was a very warm June, and my battery was on average, probably warmer than that used in any of the AVTA tests (which only have reported the lower cycling efficiency from below-turtle to "100%" charge cycles).

If you have a significant seasonal change in ambient temperatures, the increase in charging efficiency in warmer weather (less of the Wh from the wall is used to warm the battery while charging) is easy to observe.

So I would expect my warmer battery in June to have had relatively high cycling efficiency, both nominal and real.

For as long as I have been watching my packs gid numbers since ~March 2013 (with the exception being during the 3227 update wild-gid-chase) the gid loss has closely matched the nominal kWh loss, so I think it's very likely the actual loss of available capacity is probably close to 13% (to date) as shown by both, after correcting for the common ~11% (as of this date) error.

And, unless evidence shows up indicating otherwise, I think the loss of average available capacity of my pack, probably comes close to reflecting the actual capacity loss of my battery pack, as it seems to have for the LEAFs in the various AVTA reports.

What is this LBC you keep talking about?

Why involve carwings reports at all? Oh, you have stock 16" tires and are correcting for odometer/speedometer inaccuracy. Fine do the math for that if you don't want to put on the correct size tires to get rid of that inaccuracy. Next time you get tires you might want to get something with an RPM near 810-815 and that will prevent you from having to do odometer math.

Why do you trust the SOC% for 80% but then use the unscientific method of discharging to variable amounts near LBW and VLBW without specifying a bottom percentage to standardize on or at least tracking the amount used between 80 and the end of test?

Why not just use kWh as reported by leafspy? Or the kWh reported by an openEVSE?

AVTA reports are based on 120V and 208V charging not 240V so the efficiency is better on your car if you charge at home with 240V than the test from AVTA.

AVTA reports also are listed as 2012 model for the 3.x KW charger and 2015 for the 6.x KW charger so I hope you looked at the correct report to pull your efficiency numbers from (not based on the year but based on the charger). And I would use the charger specific reports not the fleet reports.

Why do any testing that involves wind, air temperature, tires, rain, and other variables over long periods when you can do all the testing in your garage with the car in Park?

If you are going to to them on the road you should at least find days once or twice a year with little to no wind and the same temperature, same tire pressure, no climate control, document kWh and SOC %. There is no point in doing them summer and winter and trying to back the numbers for an actual trip into some measure of battery capacity.

I'm sorry I'm not seeing any additional accuracy or better method in what you are suggesting.