edatoakrun wrote:If you, "LEAFfan", or anyone else has ever actually experienced anything different from CarWings than as described above, please report exactly what it is you are seeing.
Carwings is a much more accurate source of energy use data than your dash gauges.
I have tried to follow your extensive and detailed arguments in multiple threads about using Carwings data to establish battery capacity loss, and I have to say I am totally confused about what you are trying to say. What element of the CW data is more accurate than the dash or nav figures regarding energy use efficiency, exactly, and why?
We have over 29,000 miles on our car, by the odometer. It has had all the firmware updates applicable to the VIN, and we have pushed "OK" religiously every day to allow Carwings to collect our data. Carwings reports that we have traveled a total of 27,927 miles, using 4417.3 kWh of energy in the process, for an average of 6.32 m/kWh over that period.
My nav system energy history has never been reset in that two years, and it reports an energy economy average of 4.5 m/kWh. My dashboard energy economy average was never reset until 27,000 miles (when I replaced the tires) and it read 4.4 m/kWh at that time. Since then, it is reporting 4.1 m/kWh average, which I attribute to the new Kumho Ecowing tires being less efficient over the last 2,000 miles.
We have a Blink charger installed in the garage on a separate TOU meter which has been used to charge the Leaf almost exclusively during the last 2 years. From our SDG&E billing, we have fairly complete records of our "from the wall" energy usage for this period. Even ignoring the small amount of opportunity charging we have done (which would probably cancel out the preheating/cooling we have done in the garage while not driving) the Leaf has consumed over 8,000 kWh from the wall in those 29,000 miles. Allowing for 90% charging efficiency (which seems to be the consensus from what I have read here), we have put at least 7200 kWh into the battery, which would indicate about 4 m/kWh average efficiency. If charging efficiency is actually higher or lower, that figure would have to be adjusted accordingly, but I would be surprised if it was off by more than .5 m/kWh.
So Ed, how do you explain the large discrepancy in these energy efficiency numbers reported by Carwings as compared to the dashboard, the nav, and the "from the wall" efficiency figures we have experienced with our car over an extended period of time? The definite outlier is the 6.32 m/kWh CW figure, and I do not understand how that can be touted as the "most accurate." It is fully 50% higher than the more realistic numbers from the dash, nav and FTW usage figures, which average 4.2 m/kWh. It appears to gain this higher efficiency by calculating an unrealistic savings from regeneration which is completely out of proportion to my real-world experience. Why is this a better or more accurate number to use in your battery capacity calculations? What am I missing?
Yesterday, our car drove ~70 miles by the odometer from 100% charge to below VLBW ("---" on the Guessometer, but no turtle mode), with most of those miles on the freeway at 65mph. Our car has all 12 capacity bars still showing, so I assume that we have not yet lost 15% capacity. If the car is really capable of 6 m/kWh efficiency, as Carwings reported for the trip, we used only 11.6kWh. Is that a realistic number to use to estimate the battery's capacity? That would indicate it has degraded almost 50% from the original 21.5 kWh (or whatever it was when new), and that I should have been able to drive 130 miles on a 100% charge when it was new, neither of which are realistic figures. I have never trusted those CW numbers, and don't understand why you do. How is it that the top ranking drivers achieve in excess of 20 m/kWh in my region? Do they only drive downhill or something?
La Jolla, CA
2011 SLe #1317 del. 4/1/11
1st bar lost at 31,953 miles
2nd bar lost at 38,685 miles
3rd bar lost at 50,711 miles
4th bar lost at 59,758 miles after 64 months
Battery replaced at 61,307 miles.