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surfingslovak
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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 1:21 am

JPWhite wrote:2. Driving range is dropping faster than the battery capacity indicated. (Nissan are *not* hearing this).
It seemed that at least 3 owners expressed that an approximate 30% capacity drop equated to a 50% driving range drop
....
Thoughts? Comments?
Image

JP, couldn't agree more. I believe that in addition to underwriting battery capacity, Nissan needs to address instrumentation problems to ensure that owners are not losing additional range due to GOM antics or a prematurely triggered low battery warning. I raised this issue in the other thread, and only received somewhat bewildering comments from Phil and a few others. In all honesty, I don't think that it matters very much why these cars are losing range, as long as their owners can be sure that they won't drop below a certain autonomy threshold during the warranty period.

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 3:17 am

I just listened to the town hall meeting and came away with the impression that it was much more positive and useful than was portrayed by some of the early negative reports we have seen. The key issue I heard for folks in Phoenix, as both JPWhite and cwerdna have said just above, was that range is what matters, and their range experience does not map to the nine bar criterion Nissan has set. I see four parts to this:
  1. 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.
  2. A point that several questioners tried to address, and that Andy continued trying to wiggle out of, was that at the end of 5 years/60K miles Phoenix owners will have a car with a 30% degraded battery, and no more warranty support, even though the battery will probably have been replaced before that. I think the only answer to that for people who purchased is going to be knowing a battery replacement price.
  3. 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. 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. 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. 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.
  4. 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. Whatever that point is, it is undoubtedly going to arrive at a higher percentage of total capacity as the battery degrades. It will almost certainly arrive even at a higher percentage of usable capacity. This will multiply the range loss discussed in the point above.

Bottom line: It's bad enough to discover that a car with an EPA certified range of 73 miles may still be behaving “normally” if it drops from there to 51 miles in a comparable test. But from the points above the range appears likely to “normally” drop, on a proportional basis, considerably more than that. I don't blame the Phoenix folk for considering that unacceptable.

Ray
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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 3:54 am

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.

planet4ever wrote: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.
Last edited by surfingslovak on Tue Jan 15, 2013 4:36 am, edited 4 times in total.

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 4:06 am

I'm going to further reinforce the message that the Phoenix LEAF owners have been experiencing, that several impressed upon the Nissan executives in the meeting and that JPWhite, surfingslovak and planet4ever have discussed above:

RANGE DECREASES FASTER THAN BATTERY CAPACITY

I have discussed this important issue a couple of times in the past, so I will pull a couple of those posts up here for quick reference:

A couple of reasons why range reduces faster than battery capacity:
RegGuheert wrote:I think we should all plan on losing drivable range faster than we lose capacity in a BEV. There are at least two reasons to expect this:

1) At the same time the capacity of the cells is being reduced, the resistance of the cells is being increased, likely by a larger fraction than the capacity reduction. This increase in resistance means that the battery will be less efficient and that you will lose more range than just what would be indicated by just a capacity calculation. (BTW, this additional loss will mean higher temperatures in the battery, as well.)

2) Unless we are willing to call a tow truck to get to our destinations, we all have a "mental reserve" that we add to any trip to ensure that we get to our destination. For some it may be bars, for others, it may be GOM miles and for still others it is GIDs. Whatever it is for an individual, it is what they are comfortable with and it does not change as the capacity decreases. For illustration, let's take a case where a driver can travel 90 miles in their BEV when it is new until they *believe* that they only have 10 miles left. They likely will feel they have a car with a 90-mile range, even though the car can go 100 miles. Then let's say the car loses 50% of its range. This driver may then feel they have a car with only a 40-mile range. The car has lost 50% of its range, but because of the "mental reserve" needed to get safely to a destination, the driver feels the car has lost 56% of its range.

In this case, perhaps losing three bars results in a range loss of close to 35% when resistance increase is included. Combining that with the idea of a reserve needed to get to a destination, then the numbers don't seem too crazy.


Nissan has been testing battery capacity of degraded cars, not range:

RegGuheert wrote:
GreenPowerDP wrote:The message we heard in the open letter is that the range loss that is being reported is within design specifications, and that Nissan wants to address customer concerns.
That's not exactly the message that I heard. Look carefully at the words that Carla Bailo wrote:
Carla Bailo wrote:• The Nissan LEAFs inspected in Arizona are operating to specification and their battery capacity loss over time is consistent with their usage and operating environment. No battery defects were found.
Note that she says the "LEAFs" "are operating to specification" and then talks about battery capacity. She only mentions range in one sentence that I saw in the entire letter.

In fact, I do not think Nissan has any idea what the RANGE of the cars that went to Casa Grande is. Why do I say that? Because, according to the owners of those cars, Nissan didn't drive them far enough to determine range. While this might sound like a nitpick, I will say that it is a central problem in the communication chasm that exists between Nissan and LEAF owners. We have been talking about "battery degradation" around here because we know that shortens range, but as Tony, Ed and Azdre have recently been correctly pointing out, the REAL issue is range.

Does it matter? I have come to believe that it does. To start with, the Nissan LEAF starts with a very limited range compared with most cars any of us have driven before. Any reduction from that range is a big deal. Also, The recent range tests showed some cars where a large percentage of the range is bottled up below LBW and VLBW. Driving a Nissan LEAF after VLBW is akin to driving an ICE car with the fuel gauge pushing against the empty peg, except you likely have fewer miles to go and refilling is more difficult.

To make the point more clear, let's consider the extreme case: Imagine driving a Nissan LEAF which has 100% of the battery capacity of a new LEAF, but the VLBW comes on as you pull out of the driveway each time. I can tell you that I do not want to drive that car, even though it might go farther than my current LEAF. Why? Because it is virtually unusable in that condition.

By NOT testing the RANGE of the cars sent to Casa Grande, Nissan missed an opportunity to experience first-hand the problem that their customers have been complaining about.

IMO, we as a community need to break our habit of referring to range and battery capacity interchangeably. They are not interchangeable and we are contributing to communication issues with Nissan whenever we do this.


There may be other reasons that Nissan need to look more closely at range and less closely at battery capacity. For instance, surfingslovak has noted on multiple occasions that the gauges seem to be squirreling away more and more battery capacity below LBW and VLBW as the batteries degrade. If true, this will cause the usable range of the vehicle to go down even faster than it would otherwise.

There is also Peukert's law, which causes batteries to provide less total energy at a higher rate of discharge than at a lower rate. As a battery degrades in capacity, the effective rate of discharge is higher, since the power is the same but the capacity is lower.

All that said, I do not think a warranty based on range is at all feasible. As such, Nissan probably has no other choice than to go with degradation of battery capacity. But let's please make sure that none of us believe that a 30% drop in capacity equals a 30% drop in range. If the LEAF battery degrades 30%, then the usable range of the LEAF drops by significantly more than 30%.
RegGuheert
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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 5:40 am

surfingslovak wrote:I raised this issue in the other thread, and only received somewhat bewildering comments from Phil and a few others.


I may have skimmed over that post but quite frankly I think my response would be similar WITHOUT watching the town hall meeting. When I heard the complaint the first time on the video I discarded it as exaggeration, hyper-vigilance, whatever. But when you hear the same complainant echoed by many at the meeting it sinks in that somethings up. Chelsea tried to re-direct and focus Nissan to this point at some point in the dialog, but I think it also fell on deaf ears.

Besides this I found the meeting to be generally positive, much more so than some of the commentary on MNL lead me to believe. The news about 600 QC's in the ground by spring 2014 was very welcome and answered one of my questions, can't wait to see them go in. I believe the warranty is a reasonable compromise for the heat related degradation, its just not enough by itself. The meeting certainly opened my eyes to what the AZ folks are experiencing and underlines the importance of holding this meeting in the first place. My fear is that Nissan didn't hear/comprehend everything that was expressed regarding range and have still yet to bring adequate solutions to the problems experienced by customers in AZ.
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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 9:53 am

RegGuheert wrote:I'm going to further reinforce the message that the Phoenix LEAF owners have been experiencing, that several impressed upon the Nissan executives in the meeting and that JPWhite, surfingslovak and planet4ever have discussed above:

RANGE DECREASES FASTER THAN BATTERY CAPACITY

RIGHT ! Thanks for the emphasis. And to be even more clear -- expressed already in the "smaller fineprint" of your post ;)

WE CARE ABOUT PRESERVING AUTONOMY (RANGE) *NOT* BATTERY CAPACITY
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 11:13 am

+10! This is exactly my experience AND my concern!

LEAFer wrote:
RegGuheert wrote:I'm going to further reinforce the message that the Phoenix LEAF owners have been experiencing, that several impressed upon the Nissan executives in the meeting and that JPWhite, surfingslovak and planet4ever have discussed above:

RANGE DECREASES FASTER THAN BATTERY CAPACITY

RIGHT ! Thanks for the emphasis. And to be even more clear -- expressed already in the "smaller fineprint" of your post ;)

WE CARE ABOUT PRESERVING AUTONOMY (RANGE) *NOT* BATTERY CAPACITY
59,991 miles/12 bars/289 Gids/68.54 AHr/101% SOH/101.64% Hx 7May15 w/ new Lizard (barely made the warranty).
71,770 miles/12 bars/256 Gids/59.04 AHr/88% SOH/87.92% Hx 3Mar16 at lease return.

Now driving a 2016 Volt Premier. Model 3 configured.

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 11:51 am

surfingslovak wrote:
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.
I will admit that I'm one of those who are vocal about having at least an 80% warranty for 5yr 60K instead of the 70% 9bar warranty. But it doesn't mean that I'm hung up on a percentage or bar capacity warranty. If you think so, you clearly misunderstood me. The main message from me is that whatever Nissan is offering right now (9 bars) isn't good enough for hot climate owners.

The reason for my focus on the bar or percentage of battery capacity is only because I was simply trying to speak in Nissan's language so there's a commonality in the discussion. But if Nissan is willing to change their language and start speaking in terms of driving range and not battery capacity like other Phoenix owners want to, that's even better and I'm fully behind it, too.

So I'm definitely not hung up on the language of measurement like you guys think. What I'm hung up on is the lack of an acceptable remedy being offered by Nissan so far, no matter what language of measurement so far (capacity or range).

If you ask me (or any sensible person) which language of measurement I prefer, of course it's going to be actual range.

You guys are assuming that the reason several people at the town hall stressed on the range instead of the capacity because they're very technically accute about the differences between the two so they tried to impart on Nissan to use the right measurement (driving range). I would proffer to say that they were driven to prefer to discuss range simply because

1. the discussion on capacity got complicated too quickly at the town hall, given that the bars are not linear to begin with, compounded by the fact that the instrumentation is not accurate to begin with. So I think the audience simply wanted to divert the discussion toward a simpler method of measurement to keep the discussion simpler and not be hung up and run around circles all night discussing the technical aspects of the bar or percentage of capacity accuracy.
2. the unit of measurement they've been using for themselves all along has been driving range until they hit LBW or VLBW or Turtle, whichever is the limit they can stomach.

I think it was as simple as that. But hey, if this helps uncover that driving range is actually much lower than capacity, that's fine and dandy, too. But we can't jump toward conclusions about this based on a few testimonials at the town hall that lack clear common baselines without doing further testings. But maybe somebody can go back to Tony's Phoenix range test data to see if they can use these data points to draw out such a conclusion or not.

The reason I was negative over all about the town hall is because I think too much time was wasted discussing things that are not relevant to the central theme, which should have been a dialogue starting with Nissan asking Phoenix owners what they think is an acceptable solution, and Phoenix owners telling them what it should be, whether it be a warranty or battery swap or conversion to lease or whatever, and Nissan and Phoenix owners spending the majority of that time brainstorming in a dialog to come up with a solution that's acceptable for both Nissan and Phoenix owners. To me that's the elephant in the room that was totally ignored that night at the town hall.

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 12:42 pm

2 dumb questions after listening to the video. I am no engineer but I stayed ata Holiday Inn last night.

1- isn't the battery fix as easy as replacing the weaker/damaged backs and that will bring the battery pack back to 100% like new?

2- if they replace the battery after down to 8 bars, they made it seem like they would bring you back up to a certain level but did not hear 100%. Now that makes no sense to me, that is like having a damaged tire covered under warranty and giving you a barely used "new" tire vs a brand new tire. What am I missing here?

Tia,

Ian B

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Re: Summary of Nissan LEAF Town Hall Meeting on 1/8/2013

Tue Jan 15, 2013 12:49 pm

What I have slowly come around to understanding from this and the related history of discussions on battery capacity and range is that current batteries are rather mysterious "black boxes" whose properties are degrees of magnitude more complex than most of us who are not battery engineers would have expected. It is almost as if we are entering an Alice in Wonderland world of distorted perspectives and elastic time, where ordinary, everyday laws of physics and "common sense" no longer apply. (It does help explain the challenge Nissan faced in engineering the GOM, however, and why they spectacularly failed to meet it.)

I've speculated before that the paradigm change from ICE cars to EVs is and will continue to be a very difficult and stressful one psychologically; this emerging view of the elusive nature of battery technology just adds another layer of difficulty to that adjustment.
TH

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