Capacity Loss on 2011-2012 LEAFs

[Boomer23]

Or a misquote from one of the AZ folks who said that they can now only make one leg of their round trip to work and back, when they used to be able to make the whole trip.

Yes, absolutely. I didn't expect internal resistance to be ever a problem with the Leaf. What piqued my interest is the fact that most everyone reports larger range loss than what's implied by their Gid reading alone. Another thing that surprised me is that my car can no longer reach quite the same energy economy it was getting last year on the identical runs. It's a bit puzzling. Has anyone else seen this?

My energy economy is actually better than last year's. Like 4.1 on the dash vs 3.8 last year. I'm probably driving slower, though, more in the Zen zone. :lol:

 

[Stoaty]

A question for this group,

Is there anyone with a 2012 car anywhere in the world having a lost bar? Is there anyone with a 2011 car that took delivery after August 2011 anywhere in the world having a lost bar?

Unlikely, since their Leafs probably haven't experienced quite enough sustained heat to reach the one bar loss. The wiki battery capacity loss section shows a few possible candidates, but since we don't know the date of delivery of these cars, hard to say for sure.

 

[surfingslovak]

My energy economy is actually better than last year's. Like 4.1 on the dash vs 3.8 last year. I'm probably driving slower, though, more in the Zen zone. :lol:

That's good to hear! I have very little data on this and contemplated talking to Phil to see if there was a way to measure internal resistance.

My recent energy economy is identical to my long term average, perhaps even a bit higher:

Lifetime average (dash) - 5.7
Center console reading (reset a couple of months ago and not touched since) - 5.9

Since it is generally accepted that the center console reads 0.1 higher than the dash, this suggests a very slight improvement. My route has not changed, traffic is about the same, and my technique isn't any different (besides, how could I really do better than 5.7? )

Thank you, and hats off, I can only dream of such efficiency

 

[cwerdna]

An Early Autumn For A Nissan Leaf Owner In Texas
PUBLISHED JULY 26, 2012 - BY JEFF COBB
http://www.hybridcars.com/news/early-autumn-nissan-leaf-owner-texas-49026.html" onclick="window.open(this.href);return false;

Thanks for the link to the article!

Boy... the non-response so far from Nissan is quite disappointing. It'll be interesting to how many capacity bar loss reports hybridcars.com gets and whether there's any way of cross-referencing their responses w/our running list here so that we can add others, while not adding dupes.

 

[foobert]

So, If I were to contemplate selling my car now (9 months of ownership), what tax "rebate" liabilities would I owe? IIRC, the CA state will want their $2500 back if you sell prior to 2 years of ownership. But, what about the $7500 from the feds, any strings on that one?

 

[cwerdna]

So, If I were to contemplate selling my car now (9 months of ownership), what tax "rebate" liabilities would I owe? IIRC, the CA state will want their $2500 back if you sell prior to 2 years of ownership. But, what about the $7500 from the feds, any strings on that one?

And this is related to capacity loss, how?

 

[foobert]

And this is related to capacity loss, how?

:lol: Hello Pot, this is Kettle. Yeah, guess what: your post has even less to do with capacity loss

Contemplating selling my Leaf has everything to with capacity loss -- I cannot be the first to be thinking about. It's as much a statement about losing faith in Nissan and the Leaf as anything else. The economic model for the car needing battery replacement ever few years is substantially different that I was led to believe could be expected based on Nissan's claims.

I will grant you that my tax related question is fair game to point the off topic finger at, and will ask that it not be addressed here if it's so bothersome on a rather chatty, 189 page forum


[edit: 189 page forum, not 187]

 

[cwerdna]

^^^
FWIW, I live in San Jose too and wouldn't be that concerned about early capacity loss w/our weather. Yeah, yeah, my part of SJ does get into the 90s during the summer on some days and even 100, but judging from an AZ friend's occasional FB posts about his temps, I don't think we're anywhere near as bad as Phoenicians esp. since it almost always cools down at night here.

He lives near Phoenix and here are some examples:
On June 18, 2012, he posted a screenshot of 111 F temp for Phoenix from a weather app.
On July 10th, he posted a 104 F pic from his car and said at 9:40 pm, it's still over 100 F.
On Aug 5, 2011, he posted a pic of his car showing 100 F at 9:17 pm.
On July 2, 2011, he posts a pic of his car showing 117 F.

I know the topic of what to do about the Federal tax credit and CVRP if selling the car used has come up before a bunch of times on MNL. Googling for site:mynissanleaf.com tax credit what if I sell might help as would these, I think: http://www.mynissanleaf.com/viewtopic.php?f=27&t=6394" onclick="window.open(this.href);return false;
and http://www.mynissanleaf.com/viewtopic.php?f=51&t=9232" onclick="window.open(this.href);return false;.

 

[shrink]

A question for this group,

Is there anyone with a 2012 car anywhere in the world having a lost bar? Is there anyone with a 2011 car that took delivery after August 2011 anywhere in the world having a lost bar?

Based on the Wiki:

1) aubergaz, Phoenix, AZ , 11,800 miles, 9 months on 6/25/2012. 9 months prior to reported date of loss = 9/25/2011

and

2) johndoe 74, Phoenix, AZ, 13,000 miles, 9 months on 6/20/2012. 9 months prior to reported date of loss = 9/19/2011

This owner was awfully close (reported on 7/17/2012):

My Leaf has lost 1 bar[...]I woke up to see that I had only 11 bars[...]I bought it on August 31,2011 I have 12,734 miles when I lost my 1 bar[...]my car is just over 10 monthes old.

 

[planet4ever]

So, If I were to contemplate selling my car now (9 months of ownership), what tax "rebate" liabilities would I owe? IIRC, the CA state will want their $2500 back if you sell prior to 2 years of ownership. But, what about the $7500 from the feds, any strings on that one?

Actually, I think CA wants a prorated return if you sell or move out of state within three years. The federal $7500 is not a rebate, but a credit. Once they give it to you, it's yours, but that can't be until after the end of the tax year when you buy the car. They don't care what you do with the car after that tax year. That means no reduction in your credit unless you have an unusual tax calendar, even if they haven't admitted yet that they owe you the money. If you were to buy and sell within the same tax year you might have trouble claiming it.

Ray

 

[JPWhite]

So, If I were to contemplate selling my car now (9 months of ownership), what tax "rebate" liabilities would I owe? IIRC, the CA state will want their $2500 back if you sell prior to 2 years of ownership. But, what about the $7500 from the feds, any strings on that one?

Actually, I think CA wants a prorated return if you sell or move out of state within three years. The federal $7500 is not a rebate, but a credit. Once they give it to you, it's yours, but that can't be until after the end of the tax year when you buy the car. They don't care what you do with the car after that tax year. That means no reduction in your credit unless you have an unusual tax calendar, even if they haven't admitted yet that they owe you the money. If you were to buy and sell within the same tax year you might have trouble claiming it.

Ray

I also believe EVProject participants that received quick charge ports in their LEAF's at no extra cost and an EV Project supplied EVSE have agreed to stay in the program until the end of 2012. After which I believe there is no more commitment from the consumer. Not sure what the penalty is for dropping out early, I would imagine they'd examine the circumstances.

 

[mwalsh]

My energy economy is actually better than last year's. Like 4.1 on the dash vs 3.8 last year. I'm probably driving slower, though, more in the Zen zone. :lol:

Mine's gone up too. Big time. From ~4.2kWh last year to 4.8kWh now, over the long term. Actually, I just did a reset last week and was suprised to see me up at 5.1kWh as of last night, after covering about 400 miles.

 

[mwalsh]

Nissan had assured you that the car was engineered to lose no more than 80 percent capacity in five years and 70 percent in 10."

LOL! Do you see what you did there? : :lol:

 

[TickTock]

BTW, TickTock, are you still tracking your gid count?

I'm wondering what the chart you posted earlier looks like now, including the last few months, and with the bar losses indicated.

I update it daily on GoogleDoc. Link below:

MyCommute

Excellent!

Thanks.

One suggestion.

The kWh range on the vertical axis of the capacity chart is fairly compressed, making it difficult for the viewer to read with precision. Maybe you could revise, for added clarity?

Are you also tracking voltage at 80% and 100%?

How does that look?

Done. Was tricky - GoogleDocs has a few bugs that can be really frustrating when dealing with any meaningful amount of data. Anyway, if you click the "Entries" tab at the bottom, you can access the raw data that the graphs are based on. I do have voltages captured there.

 

[edatoakrun]

Please note that there are now no dated reports of lost battery capacity bars for over a week, and no reports of second or third bar loss for two weeks.

http://mynissanleaf.com/wiki/index.php?title=Real_World_Battery_Capacity_Loss" onclick="window.open(this.href);return false;

There is seems to be a trend of lower bar loss reports, since a June maximum. this is despite the publicity campaign currently being waged to characterize LEAF batteries as “defective”, which would likely result in a higher proportion of bar losses being reported, and the increasing trend of listing less-reliable second-party reports of bar loss.

Also note, that the seasonal lag after the Summer solstice means that daily average temperatures have now declined, For example, the last day of 107 F average in phoenix was on July 13.

http://www.accuweather.com/en/us/phoenix-az/85003/july-weather/346935" onclick="window.open(this.href);return false;

While temperatures have decreased a few degrees, it is still much hotter everywhere than it was in mid June, when capacity bar disappearance seems to have been occurring more frequently. So if battery capacity bars actually represent a fixed percentage of permanent capacity loss, due to degradation, I believe that the report rate should still be increasing, rather than decreasing.

If this trend continues, it will, IMO, be further evidence that both battery bars and lower gid counts reflect factors other than just battery degradation.

The only alternative explanation of this that I am aware of, is that the LEAF BMS may be restricting charge level under extremely hot climate conditions, and that part of this “lost” capacity is not due to degradation. Access to a fraction of the “top” of the battery capacity has been restricted, presumably to prevent the battery degradation that would result from this abuse.

 

[opossum]

Update to the "10 people I know" sample (updated #9)...

1. 2 bars
2. 2 bars
3. 2 bars
4. 1 bar
5. 1 bar
6. 1 bar
7. 1 bar (then sold car)
8. on the cusp of losing 1 bar
9. No known capacity loss. 80% charges, owned 16 months, only 7491 miles driven, garage cooled to below 90 degrees.
10. No known capacity loss. 80% charges, owned 1 year, only 5000 miles driven

So...

70% have already lost 1 or 2 bars (15% to 30%+)
10% have just about lost 1 bar (~15%)
10% no known loss w/ 80% charges in 16mo/7.5k, A/C in garage
10% no known loss w/ 80% charges in 1yr/5k

Background: There are 10 people (including my wife) I knew before they purchased Leafs (or met immediately after they purchased their Leafs). I did not meet any of these people *because* they began complaining of capacity/range issues. I simply met them before or immediately after they purchased Leafs. And now, 9 to 15 months later, let's check in on those 10 cars (all here in Phoenix) and see whether they have lost any capacity...

 

[edatoakrun]

"TickTock"


How does that look?...

https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dHNwVmRkNkFnaEVOQTVENW5mOTZlb0E&pli=1#gid=1" onclick="window.open(this.href);return false;

Excellent.

So, it looks to me like your available capacity increased by about 8%, or 1.5 kWh, between your initial report on October 1, and your February capacity maximum, Is that a fair assessment?

Anybody have an explanation for the relatively constant ~393 V reports, at varying levels of kWh capacity?

It will be very interesting to see, when and if a capacity increase recurs this fall.

Keep up the good work!

I wish many more of those with gid/soc meters would learn from your example, of gathering and publishing data.

 

[edatoakrun]

Please report if the other 6 with bar losses also spent very large amounts of time at 100% charge, as your LEAF has, and/or also have the same high miles, that your car has.

Update to the "10 people I know" sample (updated #9)...

1. 2 bars
2. 2 bars
3. 2 bars
4. 1 bar
5. 1 bar
6. 1 bar
7. 1 bar (then sold car)
8. on the cusp of losing 1 bar
9. No known capacity loss. 80% charges, owned 16 months, only 7491 miles driven, garage cooled to below 90 degrees.
10. No known capacity loss. 80% charges, owned 1 year, only 5000 miles driven

So...

70% have already lost 1 or 2 bars (15% to 30%+)
10% have just about lost 1 bar (~15%)
10% no known loss w/ 80% charges in 16mo/7.5k, A/C in garage
10% no known loss w/ 80% charges in 1yr/5k

Background: There are 10 people (including my wife) I knew before they purchased Leafs (or met immediately after they purchased their Leafs). I did not meet any of these people *because* they began complaining of capacity/range issues. I simply met them before or immediately after they purchased Leafs. And now, 9 to 15 months later, let's check in on those 10 cars (all here in Phoenix) and see whether they have lost any capacity...

 

[RegGuheert]

Anybody have an explanation for the relatively constant ~393 V reports, at varying levels of kWh capacity?

My guess is that the lower the energy, the more out-of-balance the cells are (or the cells have lost capacity).

 

[RegGuheert]

The only alternative explanation of this that I am aware of, is that the LEAF BMS may be restricting charge level under extremely hot climate conditions, and that part of this “lost” capacity is not due to degradation. Access to a fraction of the “top” of the battery capacity has been restricted, presumably to prevent the battery degradation that would result from this abuse.

If this is not all lost capacity, but rather capacity has an inverse relationship with temperature, then one of two things must be true:

1) The voltage reported by the Leaf as read by the GIDmeter is not absolute temperature, but rather it has been adjusted before being reported.
2) The battery itself has some sort of temperature characteristic which causes it to have a higher voltage at higher temperatures, thus self-limiting charge. This seems very unlikely, since this idea would be contrary to the idea of thermal runaway which is the normal characteristic of lithium-ion batteries. If Nissan has somehow managed to achieve a "self-limiting" lithium-ion battery chemistry, that would be attractive.

Frankly, 1) above seems more likely.