ttweed said:
I really love this idea, and it would indeed allay my growing fears about battery degradation as an owner, but looking at it from Nissan's viewpoint as well, I still don't see how "premature capacity loss" can be accurately defined to everyone's satisfaction. We all knew going in that the batteries would degrade and that it would be somewhat dependent on the conditions of usage. Nissan was very clear about that, but I think it is also clear to everyone that there is some kind of elevated rate of degradation that is taking place in hot climates beyond what was expected or could be considered acceptable. Where do you draw the line, though, between what is reasonable capacity loss and what is "premature?" Whose expectations regarding performance should prevail in making that decision? Is the customer always right? What objective standard is there that can be used to judge normal and acceptable capacity loss--their previous marketing claims regarding range? I think we are seeing that with careful "spinning" of the data, measurements and statistics, arguments can be made on both sides of the equation.
While this is true, I do think that there is a serious communication disconnect here. Most consumers are not familiar with the particulars of lithium ion chemistries, their lifecycle and aging characteristics. If the disclosure form says "expect 80% capacity remaining after 5 years of use" most people will take it as 4% or 5% degradation per year. We all know now that this is not the case.
I know from my own situation, and I have worked very hard to find and get data from comparable products, that I would have described 8-10% degradation in the first year as excessive. I discussed this with a friend of mine over the course of many months, and we both wondered if capacity loss would hit 5% in the first year, and then level off. As it turns out, about 8% is normal, and Nissan must have
simulated this extensively. Although they likely knew upfront, this was not communicated properly.
Likewise with climatic influences. We are all educated consumers, some of us even highly so, and we mean well. How long did it take us to figure out that the battery might be degrading 50% faster in Phoenix than in the rest of the country (and about three times faster than in Seattle)? And we still don't have consensus on it. Had the consumers in Phoenix known that 12% degradation in the first year of ownership was expected, many of them would not have bought. While the sales impact would likely have been significant, the situation we are dealing with could have been averted.
What is the solution to all this? Honestly, I don't know. Apparently, the battery aging characteristic is not quite to the liking of some of the consumers that purchased the vehicle. Can't change that. While there might be many owners that don't need much range for everyday driving, this is not something that can be assumed of everyone.
So what to do? Should the consumers that will not be able to use the vehicle for their commutes be able to return it or get a new battery? How many refreshes would be reasonable in hotter climates? Would more frequent charging (and better infrastructure) be acceptable until better batteries and other Nissan EVs are available? It will be interesting to see what the eventual outcome will be.
As for the future. I don't think that it's appropriate to assume that most consumers will be OK with 10% range drop in the first year. Especially in a tightly range-constrained vehicle. This should be disclosed. Another way of dealing with it would be to include 5% extra battery capacity (2 modules) without advertising it. Assuming slightly understated nominal performance of a new vehicle, consumers would be pleased to have better range than advertised in the first year, and content to see that the degradation curve from nominal down to the projected end point was largely linear and more easily predictable.
Another possibility is to advertise vehicle range in a different way. If the Leaf was sold as a 65-mile car, it would not attract buyers with longer commutes, and owners would not have a reason to complain when the range drops 10% in the second year of ownership.
