Capacity Loss on 2011-2012 LEAFs

[Stoaty]

However, I would not go as far as saying that the observed "rapid degradation" is erroneous. Even 15%, a number that reportedly came from Nissan, after one year is very significant. It's nearly unheard of in comparable lithium-ion EVs, at least in my experience. This figure would be OK as an outlier, but not if a significant number of owners experienced it.

Yes, Azdre/opossum were told that the best Leaf that Nissan tested at Casa Grande had 14% capacity loss. That means every single Leaf that was tested (presumably those with 2-3 capacity bar loss) had capacity loss far greater than Nissan represented as the expected loss when they were marketing the Leaf. We know of 55 cases of loss of one capacity bar. I would guess the actual number to be at least 3 times that many.

 

[edatoakrun]

="surfingslovak"...As to the perceived or overstated loss of range: the last Gid count on my vehicle was down 5% and the range was down 8 to 10%...

What are the dates and charging and driving temperatures of the two tests?

Depending on whether those (or other) variables had greater effect on your range and/or gid count, your results might tend to contradict TickTock's.

 

[edatoakrun]

However, I would not go as far as saying that the observed "rapid degradation" is erroneous. Even 15%, a number that reportedly came from Nissan, after one year is very significant. It's nearly unheard of in comparable lithium-ion EVs, at least in my experience. This figure would be OK as an outlier, but not if a significant number of owners experienced it.

Yes, Azdre/opossum were told that the best Leaf that Nissan tested at Casa Grande had 14% capacity loss. That means every single Leaf that was tested (presumably those with 2-3 capacity bar loss) had capacity loss far greater than Nissan represented as the expected loss when they were marketing the Leaf. We know of 55 cases of loss of one capacity bar. I would guess the actual number to be at least 3 times that many.

Yes, a sampling of 6 (or 11?) LEAFs were selected because their displays of 2-3 lost capacity bars indicated atypically high capacity loss. Unfortunately, only a few of those Casa Grande owners have reported both what Nissan told them about actual capacity loss, all reporting in the 14%-16% range, for their LEAFs and others, IIRC.

So apparently these reports indicate all of those cars, according to Nissan, were displaying losses of capacity bars, given the often quoted values those bars are believed to represent, larger than the reductions in actual battery capacity.

I don't Think it's out of the question that Nissan told Casa Grande LEAFs owners accurate reports of capacity loss. TickTock's long-term documentation of his LEAFs battery capacity, which, IMO, is be the most comprehensive, tends to indicate Nissan gave him an accurate battery assessment, from Casa Grande . Why his car got bars back, and no others have reported the same, is the unanswered question.

IMO, only when Nissan is forthcoming with further explanation, and/or LEAF owners better document actual capacity, by well-conducted range tests with all variables controlled, over one or more years of seasonal temperature conditions, will we understand what bar losses actually indicate about capacity loss, temporary or permanent.

 

[dusty2050]

I'm too lazy to quote people. Two things. TickTock has awesome data. But also remember he ALWAYS had some weird problem with his pack since he bought it, so I would be cautious to apply things going on with his car to everyone else's.

The other thing is I still have the original firmware and went through last summer no problem. I have one of the lowest VINs in the list. I'm sorry but this is not a software bug.

Agree there is no way this can be software bug

 

[surfingslovak]

What are the dates and charging and driving temperatures of the two tests?

Depending on whether those (or other) variables had greater effect on your range and/or gid count, your results might tend to contradict TickTock's.

My apologies, I might not have as complete data set as TickTock. My latest batch of range tests was conducted in mid June, in moderate summerly temperatures.

Please have a look at the wall recharge data - 22.97 kWh on June 24. Last Gid count prior to that day was 222 Gids on an 80% charge on June 13. I have a comparable data set from January 16, which indicates 24.34 kWh. I drove down from 80% to turtle, and the Gid count was 231 at the beginning of the test.

This suggest a capacity reduction on the order of 5-6% over five months.

The calculated usable capacity in January was around 20.3 kWh versus 19.3 kWh in June. I was at 21 kWh usable capacity on December 5. Total measured range loss is about 8%, which is consistent with the decline of usable battery capacity from 21 kWh to 19.3 kWh between December and June.

Disclaimer:

I took delivery in June 2011 and I did not perform a range test or get a Gid reading until December. Last Gid count was 266 couple of weeks ago. I never had a software update installed, not even the recall, until last week.


January 16, 2012:

June 24, 2012:

 

[TonyWilliams]

Perhaps this thread should be closed and new ones should be started to discuss/report on various aspects?

There's so much chatter here, that you passed right over my post above !!!! I started a thread as a "page 2" to discuss issues specifically pertaining to the battery degradation and range/autonomy issues:

Click here for the Summary

Actually, before I posted, I did glance at the 1st post of your other thread.

At the time, I wasn't sure how that thread would differ from this one. What's the criteria that someone should use to post there vs. here? Is everyone else clear why a post should go here vs. the other thread?

I'd prefer the other thread be reserved for more serious discussions about the exact same issue, and I'll try and keep a first page summary that will help more casual readers understand the issues, and what the current status is.

The lemon law stuff you posted is semi-interesting, but it might be a tough battle given that Nissan doesn't warrant capacity at all and Nissan seems to indicate the degradation is "normal". Usually (always?), when lemon laws are involved, it's related to warranty repairs.

Yes, I try to keep an arms length from advocating any of the methods to resolve these issues. I think the highest likelihood of success is numerous individual lawsuits, as any one legal decision doesn't sink everybody.

The Lemon Law stuff is obviously going to be more hit and miss... You don't know which states Nissan and other manufacturers have in their back pocket. But, the cost is low. Sending an unprepared owner in complaining of battery issues is likely a BIG loser, much like sending sheep to slaughter. For any method, I'd recommend legal help, or specific consumer advocacy groups.

 

[surfingslovak]

IMO, only when Nissan is forthcoming with further explanation, and/or LEAF owners better document actual capacity, by well-conducted range tests with all variables controlled, over one or more years of seasonal temperature conditions, will we understand what bar losses actually indicate about capacity loss, temporary or permanent.

That's going to be the tough part. Moreover, many owners might never see turtle mode, there is just too much fear or apprehension. Given this situation, we likely won't have comprehensive enough data set to prove something. If we simply read data off the CAN bus and make projections based on that or rely on LeafScan, this can always be countered by some ominous software bug. Our biggest asset so far have been Gids, especially after Phil confirmed that they represented 80 Wh of stored energy. Given what we have seen and TickTock's meticulous data collection, this might be questioned now.

On the other hand, I see more and more owners braving the 100 mile challenge. They never drive down to turtle, unless they have to, and you can forget the controlled environment requirement. That said, I'm seeing some data, which suggests that I'm not the only owner with 18 to 19 kWh of projected usable capacity. Recall that we agreed on 21 kWh being the reference figure for new Leafs. Although this is anecdotal, range loss between 7 to 10% might be common in our area, where batteries likely age at about half the speed of Phoenix.

As opossum's sample suggests, most owners in Phoenix are seeing about 15% capacity loss (one bar down on the capacity gauge). The value of each capacity bar is not believed or assumed. It's referenced in the 2011 Nissan Leaf shop manual, and many of us have purchased it.

That said, I'm not proposing an alarmist stance, quite the opposite. Being critical is key, with that I agree.

However, given that my original well-meaning report on this issue in late Many was turned into a statistically insignificant rounding error, only to see the problem escalate very quickly in the following weeks and months, I'm much more willing to side with the owners when in doubt instead of the manufacturer. Color me bad!

 

[Boomer23]

As to the perceived or overstated loss of range: the last Gid count on my vehicle was down 5% and the range was down 8 to 10%. I determined the range through three carefully executed tests from 100% all the way to turtle. According to the temperature profiling we discussed recently, I would expect the battery to age at about half or little less than half the speed owners Phoenix are experiencing in my local climate. I believe that the numbers I'm observing are consistent with that. ]

The testing that I did in early July shows data consistent with yours in that my driving range was reduced about double what my Gid data would indicate. Comparing two 100% to turtle runs in April 2011 and July 2012 showed a 13.3% driving range reduction with a 6.4% Gid reduction. Energy reduction from the wall to recharge from turtle was more consistent with the driving range reduction, though greater in magnitude.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&p=211476&hilit=turtle+gids#p211476" onclick="window.open(this.href);return false;

 

[surfingslovak]

As to the perceived or overstated loss of range: the last Gid count on my vehicle was down 5% and the range was down 8 to 10%. I determined the range through three carefully executed tests from 100% all the way to turtle. According to the temperature profiling we discussed recently, I would expect the battery to age at about half or little less than half the speed owners Phoenix are experiencing in my local climate. I believe that the numbers I'm observing are consistent with that. ]

The testing that I did in early July shows data consistent with yours in that my driving range was reduced about double what my Gid data would indicate. Comparing two 100% to turtle runs in April 2011 and July 2012 showed a 13.3% driving range reduction with a 6.4% Gid reduction. Energy reduction from the wall to recharge from turtle was more consistent with the driving range reduction, though greater in magnitude.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&p=211476&hilit=turtle+gids#p211476" onclick="window.open(this.href);return false;

Thank you for the data, Boomer! I think I may have seen it, but I've been so busy lately, it's all just a blur. One suggestion, if I may, and perhaps others will weigh in as well.

I would calculate usable battery capacity from the measured total range and energy economy recorded after last full charge. It's difficult to conduct a range test in a controlled environment and identical economy. This might give us a usable value, which factors in both battery pack capacity reduction and internal resistance increase (if any).

That said, I'm getting 18.3 kWh for your most recent range test and 21.6 kWh for April 2011. My first range test indicated 21 kWh when the Leaf was six months old. It could very well be that the my car's initial capacity was very similar to what you measured last year.

 

[RegGuheert]

Comparing two 100% to turtle runs in April 2011 and July 2012 showed a 13.3% driving range reduction with a 6.4% Gid reduction. Energy reduction from the wall to recharge from turtle was more consistent with the driving range reduction, though greater in magnitude.

That said, I'm getting 18.3 kWh for your most recent range test and 21.6 kWh for April 2011.

...which is a reduction in available battery capacity of over 15%. That is much higher than what you see with your GIDmeter. In other words, this is in *exactly* the opposite direction from the GID discrepancy TickTock recently reported.

The difference here is that Boomer23's available capacity appears to have originally been above 21 kWh, something that I do not believe is ever reported in GIDs.

I suspect that the reason so many people have thought their LEAF was not losing any capacity initially is that they were over the maximum capacity reported by GIDs, so any drop in capacity was not visible on the GIDmeter.

We bought a demo LEAF, so we really never experienced the battery when it was new. Our recent 100-mile run indicated about 19 kWh total available, but a more recent test puts that number at around 20 kWh. I'm not sure which to believe but I suppose we can live with either one assuming it does not go down too quickly from here.

 

[spike09]

Has anyone with a 2012 Leaf lost capacity yet?

 

[surfingslovak]

Has anyone with a 2012 Leaf lost capacity yet?

Yes: this is the first known 2012 model Leaf added to this list.

 

[shrink]

Has anyone with a 2012 Leaf lost capacity yet?

Yes: this is the first known 2012 model Leaf added to this list.

...and I think that leads to a double post on the wiki. I believe that user previously posted the loss on Facebook:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&start=2033#p217002" onclick="window.open(this.href);return false;

Currently, I think in the one bar loss table, #44 and #45, refer to the same car.

However, it does bring to mind another column for the wiki - model year. I think we all assumed the reports were from 2011's. That's not the case anymore.

 

[Stoaty]

...and I think that leads to a double post on the wiki. I believe that user previously posted the loss on Facebook:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&start=2033#p217002" onclick="window.open(this.href);return false;

Currently, I think in the one bar loss table, #44 and #45, refer to the same car.

After reviewing the two entries, I agree that they are most likely the same person/vehicle. I removed the one from the Facebook post, as it contains a lot less information.

 

[spike09]

Has anyone with a 2012 Leaf lost capacity yet?

Yes: this is the first known 2012 model Leaf added to this list.

...and I think that leads to a double post on the wiki. I believe that user previously posted the loss on Facebook:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&start=2033#p217002" onclick="window.open(this.href);return false;

Currently, I think in the one bar loss table, #44 and #45, refer to the same car.

However, it does bring to mind another column for the wiki - model year. I think we all assumed the reports were from 2011's. That's not the case anymore.

The wiki table is also misleading as to the sum total number of cars with capacity loss. At first glance it looks like a lot more until you realize all the two bar and three bar losses are also listed under a differrent number in the one bar loss section. The seperate bar loss sections need to be combined to better show the sequence of relative loss.

For example, while you can eaasily see that DH was #3 for the third bar, #6 for the second bar and #9 for the first bar it is not easy to figure out the number of days and mileage between those events since the are not explicitly listed. So right now if you want to figure out how quickly DH lost his second bar you need to get a calender and count the days!

 

[edatoakrun]

...and I think that leads to a double post on the wiki. I believe that user previously posted the loss on Facebook:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=8802&start=2033#p217002" onclick="window.open(this.href);return false;

Currently, I think in the one bar loss table, #44 and #45, refer to the same car.

After reviewing the two entries, I agree that they are most likely the same person/vehicle. I removed the one from the Facebook post, as it contains a lot less information.

Is the current #45, LEAF #02244 correctly listed?

Has the new owner checked in with a bar loss report?

 

[vrwl]

Is the current #45, LEAF #02244 correctly listed?

Has the new owner checked in with a bar loss report?

He contacted me via PM regarding adding his car to the 1 bar list, even though it hadn't actually lost a bar at the time he sold it. He said that it was on the edge of losing the bar before he got rid of it, and because we've seen no evidence of the capacity loss stopping and not continuing when it's that close to a bar loss, I went ahead and put it on the Wiki. I did it because I felt it was inevitable that the bar WOULD be lost on that car in the near future. Plus, it might be helpful for whatever poor soul who is contemplating the purchase of that specific vehicle.

However, if the group consensus is that it should be removed from the Wiki, I'll be happy to do that as well.

 

[Nubo]

I'm wondering if a passively-cooled pack just might be viable, and the underlying problem is more narrow. Specifically, "hot spots" in the pack. Conceivable that it's not the average temp, but perhaps zones of higher temps?

Has anyone correlated degradation vs. driving style (freeway vs. non-freeway, hills, acceleration)?

 

[dsh]

Please add me to the WIKI Table Again!

Lost 3rd Bar, down to 9 bars only!

Date of Loss: 08/14/12
Location: Phoenix, AZ
Mileage At Loss: 7,767
Months Owned At Loss: 2 1/2 weeks
Mfg Date: 3/11
Leaf VIN : 001069
Reported To Nissan: 08/14/2012
Case Number: 907-4980
Comments: 2nd bar lost in less than 2 weeks

 

[vrwl]

Please add me to the WIKI Table Again!

Lost 3rd Bar, down to 9 bars only!

Date of Loss: 08/14/12
Location: Phoenix, AZ
Mileage At Loss: 7,767
Months Owned At Loss: 2 1/2 weeks
Mfg Date: 3/11
Leaf VIN : 01069
Reported To Nissan: 08/14/2012
Case Number: 907-4980
Comments: 2nd bar lost in less than 2 weeks

Wiki updated. Wow, this is really going fast for you. So sorry