spooka said:
Yanquetino said:
The achieved range is admirably toward the high end, but 83.2 miles is still within Nissan's 76-to-84 range at 4 miles-per-kWh in a new Leaf. Those parameters are not "opinion": they are Nissan's own projected estimates."
Yanquentino, this is not an attack on you and I hope you don't perceive it in that manner. I believe that you love the Leaf and want to see EVs thrive as much as I do. We both approach the battery issue from different ends of the spectrum and the following is my argument for my concerns about the data you present on your site.
Correct, the service bulletin states a range of 76 to 84 miles. The "opinion" enters the arena of discussion when a number is arbitrarily chosen from this range and as a result, incorrect conclusions are deduced from it. The brand new Leaf that just ran the Tempe Twelve course at the speed Nissan states is needed to obtain 4Miles/KW made it 83.2 miles with 21 GIDs remaining in the pack. It is reasonable to extrapolate that it would have made 88.7 miles to turtle, based on the average of 2.9 GIDs/mile obtained at the tests end point of 83.2 miles. This is observed data that demonstrates Nissan's 84 mile upper limit in the service bulletin was conservative and that all Leafs in the test can now reasonably be compared to the upper end of the range using 84 miles to turtle vs the 80 miles you arbitrarily chose. I hope your web article will reflect this change as others have used your presented data as factual in media stories which only perpetuates the distorted data in your article. I am publicly asking you to address this and base the data on your site on 84 miles. The data obtained from this Leaf proves that Nissan thankfully does not sell new battery packs with useable capacities below 21KW (or 24KW total). When you pick a happy medium of 20KW (80 miles) you are implying that Nissan is selling new Leafs to the public in an already damaged or defective state. The issue is what happens to the pack after use, not before delivery. Your whole assumption in your article is based on the "before" aspect and leaving your article as would (IMO) show a bias on your part now that there is hard data to the contrary.
Thanks for considering this.
Hi, spooka:
Yes, I do want to see EVs in general thrive, but contrary to what others have accused, "proving Nissan right" has never been my motivation. I have said this elsewhere, and will repeat it here: if the test data had shown that the majority of those Leafs achieved a range notably below Nissan's parameters, I would have stated as much. Believe me, given the reactions from others, there have been times when I wish that were the case. But... it's not. It's just the way the math adds up using what few benchmarks and scenarios Nissan has made public. As for "attacks" on me personally... I appreciate your reassurance and approach, but I think you and I both know that there are others who have resorted to such tactics.
Please know that I do feel bad for the AZ owners involved. As I've said many times, Nissan should have addressed their concerns
much earlier: it could have made a world of difference, and nipped all the bad publicity in the bud. And I can’t blame the owners in the least for being alarmed by what they were experiencing: it was only logical to assume that those capacity bars were reliable. That certainly would have been my default conclusion had I suddenly noticed that one was missing! However, now that the test results have shown that the gauges are indeed inaccurate, I would hope that at least some AZ owners will feel relieved and reassured to know that, as Nissan confirmed with its own analysis, their Leafs “are behaving as we expected.”
I appreciate your suggestion, but hope you will understand that I feel like I have already updated
my post to be as fair, thorough, accurate, and free of "opinion" as possible. As you have probably seen, I now plot the polynomial curve for "normal" capacity degradation using the
average 80 miles in the middle of Nissan's 76-to-84 range estimate for a new Leaf. More importantly, I also include grey
error bars to display the
corresponding variance in that scale for each Leaf according to its mileage, top-to-bottom, high-to-low.
For those who assert that only the top of those bars is valid, the challenge is to first convince
Nissan --
not me-- that their estimated 76-to-84 scale needs to be
higher so that they can then prove that the AZ Leafs' ranges really were
lower than the automaker anticipated. I wish them luck with that effort. I can tell you this much, if it helps: if they are successful in convincing Nissan to raise their range scale, I will gladly alter my tables and graphs accordingly.
Finally, allow me to say that there are still, unfortunately, missing data. Since the majority of the Leafs tested achieved ranges within Nissan's scale of ranges, there must be additional factors besides heat and even mileage that affected the few vehicles that fell below those parameters: number of charges per day, 100% vs. 80% charging, time sitting fully charged, 120v vs. 240v vs. 480v, typical speeds driven, Drive vs. ECO, use of climate control, location during the hottest hours of the day, driving style, road and traffic conditions, etc., etc. These are all factors that might affect the "rate of reduction" in battery capacity, but we have yet to see those CarWings data for each vehicle --from either the owners or Nissan. I sure wish we could. For example, it would probably help explain why --with the same mileage on their odometers-- one Leaf tested in the middle of Nissan's scale, yet another fell notably below it.