cwerdna said:
It IS a problem for those in hot climates like Phoenix, AZ and TX. Others in hot climates (and a few in not so hot climates) have also lost battery capacity.
Heat impacts battery longevity and performance. That impact is worse in places like Phoenix. Nobody denies that, including Nissan. The results of the Leaf owner's tests verified that most were still operating within published limits. At what point his constitutes a "problem" is arbitrary.
Unless something is done, I'm pretty sure we're going to see another wave of battery capacity losers in those hot climates next summer as new cars reach the one year mark and others have theirs age another year. The cycle will repeat... Meanwhile, those in mild climates (e.g. San Francisco, Western WA, Portland, etc.) will see MUCH slower degradation, even w/higher mileage than their AZ/hot climate counterparts.
Battery capacity loss is normal and expected. Higher loss in really hot places is also expected and normal, just as really short range is expected and normal on a -10 degree day. Something is being done. Nissan is responding by buying back cars that fall outside of the published band, and then some.
Tony Williams said:
And there it is, as expected. If we had tested 100 LEAFs, it wouldn't be enough, since there are 40,000 worldwide. Ya, the forever impossible goal. I won't be hiring a statistician, but if you've read through our forum, you'll note that we have them here.
Statistics involves picking not only the appropriate number of samples, but a sufficiently random number of data points to avoid skewing results. Your "Phoenix sick LEAFs" test for example used what you thought were ten damaged cars, not a statistically significant number of randomly chosen cars in the Phoenix area, yet you still got results that disproved your claim ...and didn't even realize it until it was pointed out to you by Mark's simple plots of your results, which I concur with:
Simply put, because you used 84 miles as your standard instead of 76, this was not a test to see if these twelve cars performed within published acceptable limits, which would be a reasonable thing to test. It was instead, a test to prove that they would not meet the maximum value in an acceptable range, which is a nonsensical thing to test. However, by simply plotting your test results using the appropriate value (the low end of the acceptable range) your test transforms into one demonstrating that 10 out of the 12 (or 8 out of 10 depending) cars thought to be out of spec were, in reality, within (or just barely out of) spec.
Once it was pointed out that most of this skewed sampling still met specs, you shifted gears and are now trying to convince people that the published specification boundaries are some kind of ruse or conspiracy theory.
Nissan published that performance band (76-84 miles) to cover anticipated variances (as witnessed by the waiver you signed, not once, but twice) in temperature and use. They were a bit off for some cars in the Phoenix heat wave, and acknowledge that.
It is utterly irrelevant should somebody demonstrate that the performance band of cars coming out of a factory door is different than the published spec telling owners what to expect in the real world. Once again, because your latest car failed to hit 84, your test results are belying your own claims, which this time says that there is no variation in performance (no range band) of cars at the factory door. That range band could very well prove to be different than the published spec used in your study, but that is because the published band is meant to be used for real world performance. There are different specs for different purposes.
We've also got more than a few engineers, scientists, physicists, etc. Youve come to the right place!!!
For sure, and I'm one of those engineers, which highlights why your insinuation that they all agree with you is misleading.
You two that I specifically name (who very publically dispute our work here) and a tiny handful of what can only be affectionately termed "battery deniers" are clearly on opposite sides of the fence from we who are interested in the truth.
Riiight ...the truth. Everyone thinks they have the truth, which is why it is irrelevant that we do. You are arguing that majority defines truth, and you have the truth because the majority of the comments at this forum are supportive. Analogously, because the vast majority of Americans don't by the theory of evolution, it is not the truth.
Anyone interested in the truth just has to read this
response to your comment under this
article.
The motivation seems to be (for those of us watching you two) to help "save" Nissan from we "misguided" loud complainers that are bad news for the EV movement with our faulty, non-scientific FUD.
I'd rephrase that to say you are doing harm with your pseudoscience and lack of engineering knowledge to a budding and critically important new technology. Google "Dunning-Kruger" effect.
I'm also glad you are the first to broach the subject of motivation. I'm hard pressed to understand what motivated you to drive a leased Leaf into the ground (29.000 miles in a single year) other than as a notoriety seeking antic.
You repeatedly leap-frogged from charger to charger, a Leaf, designed for urban city driving of less than 100 miles on a charge, from Mexico to Canada. I’m trying to think of a better way to stifle the sales/development of the first generation of mass produced electric vehicles than by highlighting their inherent engineering limitations by taking them on missions they were never designed to do.
Anyway, the 84 mile range autonomy is repeatable.... over and over and over.
A) It is irrelevant what the performance band is at the factory door.
B) You have not pinned down what that performance band is, assuming it is relevant to do so.
Please do call us when you add to the breadth of knowledge. Maybe grab a new LEAF off a lot and take it for an 84 mile test drive in still air, 80F temps, level terrain, and a steady 100kmh ground speed with cruise control. But, first make sure it hasn't been baking in the sun all summer.
Straw men arguments work well in oral debate but are largely ineffective in blog debates, where your opponent can simply point them out time and again. For the tenth time, nobody, including Nissan has ever claimed that extreme temperatures won't affect battery performance. You signed a waiver acknowledging that performance will be a function of things like temperature, not once, but twice, assuming you leased two Leafs.
TomT said:
No, my point is that it is a very small sample of approximately .016 percent nationally. On a regional basis for regional ratings, it is even smaller at approximately .006 percent... The sample of Leafs used for Tony's measurements was considerably larger on a regional basis. National polls typically use an even smaller sample of around 1,000 for the entire nation...
But Tom, they didn't go out of their way to find 1,000 angry Republicans to poll. And a sample as high as 50% is still meaningless if you have a sample size of two. But what is really important to understand here is that it is irrelevant what range band cars at the factory door have. That is not the range band consumers can expect once the cars meet the many varied driving environments that exist out in the real world. Nobody has denied that extreme heat has an impact.
