planet4ever wrote:A number of owners are hung up on a 70% warranty when they were expecting 80%. Sorry, folks, but I think this is the wrong place to hang your argument. Nissan has always said they estimate 80% after five years, and that this will vary and could be significantly lower. (I'm quoting from the 2011 owner's manual.) To me that clearly means they predict an average loss of 20%. It would make no financial sense at all for Nissan to promise to replace the batteries in half of all of the LEAFs they have built. They had to set the replacement point lower than the average.
Right, I believe that it has been acknowledged earlier that 80% might have been a median value, and 70% orients itself on the worst performers.
planet4ever wrote:It is not clear whether Nissan is talking about 70% of total battery capacity or 70% of usable capacity. I suspect it may be total capacity, and if so that will not map well to 70% of range.
Good point, although if the discharge curve and voltage thresholds don't change significantly over the life of the battery, then there shouldn't be much of a difference, just as you said.
As JPWhite points out, you can never discharge the battery to 0% of total capacity, and it may well be, in fact probably is, true that Turtle appears at a higher percent of total capacity with a degraded battery. That in itself guarantees that percentage loss of range will be higher than percentage loss of total capacity.
Yes, we have collectively determined that the LEAF protects a fixed number of kWhs, not a percentage, at the bottom. This means that in a 30% degraded battery with 14.7 kWh of usable capacity, LB comes on at 24.92% instead of 17.4%, VLB at 12.2% instead of 8.5% and turtle shows up at 3.5% instead of 2.8%.
planet4ever wrote:I personally doubt if the floor is rising by 20%, as JPWhite suggests it may be, but I have no doubt that it is rising in a way that further reduces range.
Ray, have you read my previous comments
on the topic? I drove one of the cars at the Phoenix range test, and it did not behave the way you would expect. It was pretty clear that the LEAF has lost about twice the amount of range implied by battery degradation, when cycled between full charge and the low battery warning. There was at least one other car, which behaved the same way at the range test, and what you have heard during the Town Hall would be reflective of this behavior as well. I mentioned this several times before, and I'm sorry, but it's getting a bit tiring to have to explain it over and over again. Especially after getting the mushroom treatment in the other thread.
planet4ever wrote:At the very least the battery controller will try to protect a constant number of kWh. The experience of a number of us indicates it may try to protect an increasing kWh as the battery ages.
This was discussed before, and I tried to calculate a few representative numbers above.
planet4ever wrote:Most drivers, perhaps all rational drivers (sorry, Tony Williams) will stop before they hit turtle. As cwerdna points out, most people have a minimum point they will drive the car down to which is well above Turtle. It may be two bars, 10 on the GOM, LBW, VLBW, or some other range anxiety threshold.
Yes, exactly. Inadequate instrumentation and GOM idiosyncrasies apparently become a real problem in heat degraded cars.
planet4ever wrote:I don't blame the Phoenix folk for considering that unacceptable.
Exactly. To be quite frank, I'm getting PO'd myself that this issue is taking so long to get addressed adequately. Especially after hearing the old mantra that "it's the software and not the battery" again in the other thread. It's likely both, possibly in equal amounts. To be clear, I did my best to escalate in May last year, once I was convinced that we were seeing heat-related capacity loss, long before we had consensus on it. Now everyone is an expert, and yet we can't seem to get ahead.
When Nissan took several cars for investigation to Casa Grande last July, the owners noted that very few miles were added to the odometer. I believe that this had Tony wondering why they wouldn't perform a range test, which he did couple of months later. It was during this test when I realized that there might be something missing from the big picture. Azdre and opossum mentioned disproportionate loss of range as well. This situation is quite unfortunate, and it's easy to judge when you were not there and did not drive one of the heat-affected cars.