ydnas7
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Sun Apr 07, 2013 5:23 am

TonyWilliams wrote:
Herm wrote:Tailwind?
The course is a loop. That's how we mitigate the wind component.
Perhaps cross-wind might have a effect, or the wind gusts/calm, or (my take) - in a loop course, the benefit of tail wind is less that than the loss from a head wind.

I don't know, but it does reflect the difference between a replicable tax relevant figure (efficiency) and a variable real life figure (range)

edatoakrun
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Sun Apr 07, 2013 8:51 am

pchilds wrote:
...Carwings is worthless, why would anyone waste their time with it?
Read this thread if your LEAF needs the NTB-11-041 CarWings update :

Re: NTB-11-041 Telematics Connection Fix - dealer says no

http://www.mynissanleaf.com/viewtopic.p ... 5&start=30" onclick="window.open(this.href);return false;

If your LEAF doesn't need the update, probably the only thing wrong with your LEAFs CarWings kWh use reports, is that you are not using them.

In the OP:
TonyWilliams

...We drove about 69.2 miles until Low Battery Warning (LBW) at 3.9 miles/kWh, and an additional 8 miles (12.9 km) to Very Low Battery (VLB)...
Unfortunately, I cant find any report of the dash m/kWh at the VLBW or at the end of the 2/24 test.

Pchilds, do you know what your dash m/kWh was when you got the LBW?
pchilds

...100kph GPS, 36 psi tire pressure, 5 temp bars at start, 6 at finish.

Start GID 249
LBW 65.7 miles
VLBW 77.2 miles
End GID 18
m/kWh 4.8Total miles 79.9
Weather, traffic and temperature were the same as the last test.


Even absent the report of what both LEAFs dashes, nav screens, and the more accurate CW kwh use reports showed at the same LBW or VLBW, is pretty clear from the rest of your accounts, that the dash m/kWh was much higher in your test, than for the "new" 2013 LEAF in the 2/24 test, and so the 2011 was reporting a much lower kWh battery capacity, as both LEAFs got an identical 77.2 miles to the VLBW, right?

Take a look at this recent range test by camasleaf comparing his 2011 and 2012 LEAFs:

I want my 281!

http://www.mynissanleaf.com/viewtopic.p ... &start=550" onclick="window.open(this.href);return false;

Where again, two LEAFs got substantially identical ranges but had a large disparity between the (more accurate than dash) nav screen m/kwh, 4.4m/kWh for the "new" 2012 and 4.7 m/kWh for the "old" 2011.

And now look at my range test results from last Summer, on a single LEAF which had the the kWh use report and all the m/kWh reports change over one year:
..I chose a day with very close to the original temperature condition, and drove the exact same route over the first 87 miles of the trip, using the same mode (eco) and used my original trip logs to closely replicate the same elapsed times for each of the three (same distance) legs of the trip.

The results from 8/30/12 were:

97.3 miles to VLB, 98.9 miles in total, by the odometer.

CW: 96.5 (~2.5% under-report) total miles, at 5.7 m/kWh, 16.8 kWh used from 100% to about the same capacity level, slightly past VLBW.

Compare this test with my first test on 9/7/11:

91.5 miles to VLB, 93.4 in total, by the odometer

CW: 91.1 (~2.5% under-report) total miles, at 4.9 m/kWh, 18.7 kWh used from 100% to about the same capacity level, slightly past VLBW.
Use CW report from range test to determine battery capacity

http://www.mynissanleaf.com/viewtopic.p ... 4&start=20" onclick="window.open(this.href);return false;

I think it is very likely both you and camasleaf are seeing the same thing I first did last Summer, a large decrease in reported kWh use (and battery capacity) over time and miles driven, that is not showing up in a similar decrease in the actual driving range.

You, however, are probably seeing it with less accuracy, and noticing it much later, because you have not been using the Carwings kWh use report data, just less precise dash and nav screen m/kWh readouts, and may not have not been range testing your own LEAF on a fixed route, with controlled variables, over time.
no condition is permanent

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TonyWilliams
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Sun Apr 07, 2013 10:17 am

ydnas7 wrote:
TonyWilliams wrote:
Herm wrote:Tailwind?
The course is a loop. That's how we mitigate the wind component.
Perhaps cross-wind might have a effect, or the wind gusts/calm, or (my take) - in a loop course, the benefit of tail wind is less that than the loss from a head wind.

I don't know, but it does reflect the difference between a replicable tax relevant figure (efficiency) and a variable real life figure (range)
This falls into one those dismissing return arguements. Unless you're testing indoors, there will always be a wind component over 80 miles. Driving all four cardinal headings mitigates that.

All the cars tested this year in San Diego were exposed to the same course and predominately the same wind, which for San Diego is out of the west at 5-15 knots. Every airport has a primary west runway.

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LEAFer
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Sun Apr 07, 2013 10:31 am

I have an opinion, but without scientific backup. It's probably out there, but I am too lazy (& busy) to find the proper references. In any case, here goes.

Tail versus headwind: I believe they cancel out reasonably well. Not perfect due to the different profiles the wind "hits", but close enough for road test purposes.

However, I disagree on cross-wind. ( And when do you ever get perfect head/tail-wind ? ) The problem I see with cross-wind is that it degrades your aerodynamic efficiency in *ANY* direction. In other words, travelling a "loop" course, even if loop is simply back and forth (180 degrees opposed), will *NOT* cancel a negative effect on the return leg. The degradation is additive.

Naturally, the amount of additional drag depends on the actual angle the wind intersects w.r.t. vehicle travel, as well as the proportion of wind speed to ground speed, but the "worst" case is the 90 degree version. You "lose" both coming and going.

JMHO.
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;

Reddy
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Mon Apr 08, 2013 10:11 am

LEAFer wrote:I have an opinion, but without scientific backup. It's probably out there, but I am too lazy (& busy) to find the proper references. In any case, here goes.

Tail versus headwind: I believe they cancel out reasonably well. Not perfect due to the different profiles the wind "hits", but close enough for road test purposes.
Here's mine, from bicycling experiences. They never cancel out. Kinetic energy = 1/2 M V^2, so double the wind means 4x the KE. I think power (I can't remember) is proportional to velocity cubed. So double the wind means 8x. When bicycling, a head wind is a big killer (that's why you see bicyclists "drafting"). Bicyclists have a limited engine and slow down significantly, and therefore spend more time riding into a steady drain. Turning around, you ride faster, thus spending less time getting the tailwind benefit. It's different in a car since you probably travel a constant speed both directions. However, if you have a 20 mph head wind traveling 60 mph, that's an effective air speed of 80 mph. Turn around the other way, and the air speed is 40 mph. So 2x more wind and 8x more power going into the wind vs the other direction. Does that make sense? Maybe our airline pilot members (Tony?) can provide a better description.
Reddy
2011 SL; 9 bar, 45.80 AHr; 45,000 mi; rcv'd Aug 18, 2011
Long: http://www.mynissanleaf.com/viewtopic.p ... al#p226115"
Cold: http://www.mynissanleaf.com/viewtopic.p ... 60#p243033"

DaveinOlyWA
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Mon Apr 08, 2013 11:19 am

Its been my experience that a circular route with the same beginning and end points do not cancel out the effects of wind simply because wind shifts directio.s especially when multiple hills and valleys are involved. If the valley is configured just so, it cn change the direction of ground level wind.
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 19,653 mi, 93.47% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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TonyWilliams
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Tue Apr 09, 2013 6:21 am

Reddy wrote:.... if you have a 20 mph head wind traveling 60 mph, that's an effective air speed of 80 mph. Turn around the other way, and the air speed is 40 mph. So 2x more wind and 8x more power going into the wind vs the other direction. Does that make sense? Maybe our airline pilot members (Tony?) can provide a better description.
You described it well, I think. Boats and airplanes have different issues because the actual medium they are in moves. So the power can remain the same, but "ground" speed changes.

In a car, at a constant ground speed, the amount of time spent in a head wind versus a tailwind is exactly the same on an out and back equidistant course, which is different than an airplane which spends far more time in the headwind than the tailwind.
Last edited by TonyWilliams on Tue Apr 09, 2013 6:45 am, edited 1 time in total.

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TonyWilliams
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Tue Apr 09, 2013 6:24 am

DaveinOlyWA wrote:Its been my experience that a circular route with the same beginning and end points do not cancel out the effects of wind simply because wind shifts directio.s especially when multiple hills and valleys are involved. If the valley is configured just so, it cn change the direction of ground level wind.
Using that argument, you could drive any direction you want and claim wind changes direction.

What would you claim in a place where wind doesn't predominately change direction or speed over the course?

DaveinOlyWA
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Tue Apr 09, 2013 6:38 am

In a side by side test, wind wouldnt matter but i live in an area where there are several circular routes i can and do drive and historically, i perform better driving clockwise. The results are consistent and the variation on the trips taken makes me relatively certain i can say that outside factors of traffic, weather etc can be eliminated due to the weight of repeatable results
2011 SL; 44,598 mi, 87% SOH. 2013 S; 44,840 mi, 91% SOH. 2016 S30; 29,413 mi, 99% SOH. 2018 S; 25,185 mi, SOH 92.23%. 2019 S Plus; 19,653 mi, 93.47% SOH
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

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Wennfred
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Re: 2013 LEAF Range Test Feb 24, 2013 in San Diego; 81 miles

Mon Jan 26, 2015 6:19 pm

Would be nice to duplicate this run with the new LIZARD packs, great read.


Fred
MFG: FEB 2011, Red Recd 08/10/13 @ 19600 Miles
"Eco Mode" only. 06/24/15 - 9 CB @ 43,000mi 100% charge: GIDS=199, S=95.37, C=46.76, H=50.51 Lost 1st CB at 26300, 2nd CB 34274 3rd CB 43000 miles

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