Capacity Loss on 2011-2012 LEAFs

[scottf200]

...perhaps this has already been posted...showed up in one of my google scans...

Call 12: Report juices Nissan to refund car
Sat Oct 27, 2012 5:58 PM
http://www.azcentral.com/business/articles/20121025nissan-refund-car-sanchez-call12.html" onclick="window.open(this.href);return false;

And this is not the first time. Nissan repurchased three other cars this year from Arizona residents who also complained that the car’s batteries were unable to hold charges.
...
Phoenix resident John Noble contacted Call 12 for Action after Nissan initially refused to buy back the car after a series of problems with the battery.
...
Miller and three other former Leaf owners in the Valley were allowed to return their electric cars for a refund, but Noble wasn’t getting anywhere.

On Oct. 1, Call 12 for Action put Noble’s story on the air.

“I tried to work with Nissan for four months, and two days after the story aired, all of a sudden, Nissan was calling me,” Noble said.
...
Noble accepts Nissan’s explanation. In fact, he bought another Nissan: a Versa, which is not an electric car.

 

[edatoakrun]

="spooka"

New reports of capacity bar loss slowed to a trickle after September, and none have been reported for 18 days to date.

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

As I have mentioned before, the rate of bar loss until next Spring will be a strong indicator of the relative contributions of actual capacity loss to "gauge error", in causing capacity bar loss. If the capacity bars were accurate (and the LEAF BMS does not adapt to temperature, limiting charge levels in hotter conditions) large numbers of new LEAFs should still be losing bars, albeit likely at a slower rate than during the Summer, when they may have actually been losing capacity at a more rapid rate.

IMO it is beginning to look like "gauge error", corresponding to battery/ambient temperatures, has very likely been a major, or even predominant, cause of LEAF capacity bar loss.

If it is a gauge error, why aren't bars reappearing with cooler temps? Why would it only go one way?...

The design could require a "reset" (such as was done on TickTock's LEAF) to restore the bar display to whatever percentage, of either total or available capacity, it is intended to show.

="spooka"

...Could it be that the capacity levels have dropped below the "quick" 20% level of the degradation curve and have now leveled off for the slower death spiral toward that last 10%? These two factors could be in play: 1.The cooler temps and 2. A slower capacity loss with time because the packs are beyond the "fast" first 15% loss on the curve already.

That reasoning, of course, could not apply to the ~99% of North American LEAFs which have not reported the first bar loss. These LEAFs will continue to lose capacity over the cooler months, and large numbers would be expected to lose their first capacity bars, if the capacity bars actually were an accurate indicator of total battery capacity.

 

[edatoakrun]

="Randy3" ...current range (62 miles actual, on D setting without hypermiling), what range I got before (77 actual same driving style)...

Are those results from a range test:

From the same starting and completion SOC?

On the same route?

At the same speed?

Using identical (no) climate control?

Driven at identical temperatures?

After charging at identical battery temperatures?

With the same driver efficiency (identical regen percentage of total kWh use reported by Carwings, and estimated identical use of friction braking)?

Even if you normalize all those (and other) variables, factors outside your control will cause significant imprecision in your results.

But only a range test (or a recharge test, which likely has lesser variables causing imprecision, IMO) really can determine loss of available battery capacity.

="Randy3"...It's just too early, at 14,000 miles and 21 months age, to lose 15% of the battery...

Whatever the first bar loss is intended to show, it is very likely that it does not accurately represent 15% of total battery capacity in all cases.

 

[mksE55]

Classic over-hyped and under-performed. Randy we feel your pain. Still waiting for Nissan to rectify the issue.

Proverbial shoes continue to drop.

 

[Randy3]

No, I don't own or operate an automobile test facility. I'm just another driver. If Nissan demands that I do all of those steps, I'll be contacting Tony for his lawyer recommendation.

="Randy3" ...current range (62 miles actual, on D setting without hypermiling), what range I got before (77 actual same driving style)...

Are those results from a range test:

From the same starting and completion SOC?

On the same route?

At the same speed?

Using identical (no) climate control?

Driven at identical temperatures?

After charging at identical battery temperatures?

With the same driver efficiency (identical regen percentage of total kWh use reported by Carwings, and estimated identical use of friction braking)?

Even if you normalize all those (and other) variables, factors outside your control will cause significant imprecision in your results.

But only a range test (or a recharge test, which likely has lesser variables causing imprecision, IMO) really can determine loss of available battery capacity.

="Randy3"...It's just too early, at 14,000 miles and 21 months age, to lose 15% of the battery...

Whatever the first bar loss is intended to show, it is very likely that it does not accurately represent 15% of total battery capacity in all cases.

 

[edatoakrun]

No, I don't own or operate an automobile test facility...

"I don't own or operate an automobile test facility", either.

But I do have an ~87 mile drive I do fairly regularly, which has made monitoring my "100%" to VLBW pretty simple.

And my conclusion is that my LEAF with 13,600 miles but with fewer months since assembly and probably with considerably less long-term exposure to high heat than yours has had, is also probably fairly close to losing a capacity bar (I was seeing 9 bars at "80%" charge regularly last Summer) but has not lost anywhere near 15% of range, or of available battery capacity.

...I believe that the recharge time results are compatible with my range tests, which indicate no observed reduction in range, both probably indicating that my LEAF has no observable loss of available battery capacity (though some amount has almost certainly occurred) over the last 12 months.

I think it is also very likely that many other LEAFs have similar errors in kWh reports, quite possibly due to the gid Wh variability TickTock observed last year, and that capacity bar displays might be similarly effected. Not having lost a bar (yet) or ever having monitored my gid count, I can’t observe those results.

I do think that anyone seeing capacity bar losses or dropping gid counts should try both range and charge capacity tests, to try to more accurately determine their LEAF’s actual loss of battery capacity.

http://www.mynissanleaf.com/viewtopic.php?f=31&t=9064&start=30" onclick="window.open(this.href);return false;

Your LEAF has lost battery capacity, as has mine and every other LEAF since the day their batteries left the factory.

And for all I know, your battery pack could be down 15% in capacity.

The loss of capacity bars, however, just does not seem to be a reliably accurate indicator of battery capacity.

 

[spooka]

No, I don't own or operate an automobile test facility. I'm just another driver.

+1

Can't wait for the quantum physics line of questioning to come next

Do you generate a singularity in you Leaf every time you switch to ECO mode?
Is your range the same over the entire multiverse, even if you didn't drive in all of them that day?
Do you approach the event horizon at the same arcminute and arcsecond every time you drive to work?
Do you harness the same amount of dark energy and use the Hubble Constant when you regen?
Is your Leaf conforming to the Michelson-Morley Experiment model when moving?

Geesh

I'm just a driver too Randy and I don't need the precision of an atomic clock to tell me what is happening. That type of standard is unrealistic (allowing for an exception in possibly ONE of the multiverses). Drive your car and keep the reports coming. I plan to.

 

[edatoakrun]

No, I don't own or operate an automobile test facility. I'm just another driver.

+1

Can't wait for the quantum physics line of questioning to come next ...

Drive your car and keep the reports coming. I plan to.

So will I.

I already posted above the rather simple procedures necessary for reasonable accuracy in range test results. which you can use to track your own available battery capacity. Read and consider, and you should get data worth considering, in the future.

No "quantum physics" required, just repeat a drive under the same conditions. Choose a long trip near your maximum range that you expect to repeat frequently, to reduce the ridiculous waste of time and energy that is entailed by driving in circles unnecessarily (you will have to add a few miles at the end, to bring your LEAF to the desired SOC).

Many LEAF owners are posting (and apparently, believing) battery capacity junk data, based on capacity bar loss, GOM readings, gid reports, and range tests with uncontrolled known variables limiting the accuracy of the data, as was the result of the Phoenix range test attempt.

And if you don't want to make this effort to do a range test, if you have a way to meter, recharge capacity may actually give more accurate available battery capacity results. AFAIK, the only significant variable there is battery temperature.

 

[turbo2ltr]

GIDs at 100% charge

5/2012 (one bar lost): 228
6/30/2012 (two bars lost): 213
7/22/2012: 215
9/21/2012: 213
10/23/2012: 217
11/5/2012: 220

 

[Randy3]

No, I don't own or operate an automobile test facility. I'm just another driver.

+1

Can't wait for the quantum physics line of questioning to come next ...

Drive your car and keep the reports coming. I plan to.

So will I.

I already posted above the rather simple procedures necessary for reasonable accuracy in range test results. which you can use to track your own available battery capacity. Read and consider, and you should get data worth considering, in the future.

No "quantum physics" required, just repeat a drive under the same conditions. Choose a long trip near your maximum range that you expect to repeat frequently, to reduce the ridiculous waste of time and energy that is entailed by driving in circles unnecessarily (you will have to add a few miles at the end, to bring your LEAF to the desired SOC).

Many LEAF owners are posting (and apparently, believing) battery capacity junk data, based on capacity bar loss, GOM readings, gid reports, and range tests with uncontrolled known variables limiting the accuracy of the data, as was the result of the Phoenix range test attempt.

And if you don't want to make this effort to do a range test, if you have a way to meter, recharge capacity may actually give more accurate available battery capacity results. AFAIK, the only significant variable there is battery temperature.

edatoakrun,

First, I want to say that I have enjoyed reading your posts. I'm not trying to be negative to you when I say that I'm just a driver.

But, a couple of thoughts. Probably everyone on our forum understands why we call the Distance to Empty gauge the "Guess-O-Meter". It's been inaccurate since the beginning. I *think* we're now understanding that the battery capacity meter is also inaccurate. I'm not quite there yet. It's easy for me to understand that I'm not getting the range that the Distance to Empty gauge shows. But the battery capacity meter is different. I don't understand electricity (and electronics?) well enough to realise that Nissan has again provided us with a gauge that I might as well cover over with black tape. Is the number of bars showing on the battery capacity meter bogus?

Then there is your previous post, responding to my notification that I called Nissan to get a case number for battery capacity (losing a bar). Your post didn't just say to do a simple test drive. It talked about environmental conditions, etc. That's what brought out my comment about not operating a test facility. Your comment here makes more sense to me, just to a drive that I've done before, in a similar manner, and compare the results. Thanks for clarifying. Okay, I've done that. My daily drives are often very similar. But I've also done a route to the San Jose area several times. It's 72 miles from my house to a KOA Campground just west of Los Banos, CA (a favorite charging point). The last time I made that drive the car hit VLB before reaching Los Banos. When I first drove it (approximately April 2011), it hit VLB just before the KOA. It's about a 13 mile difference. Based on this, I no longer feel comfortable making this trip in the LEAF. (BTW, I'd love to have some L2 EVSE's along this route, maybe in Los Banos.)

edatoakrun, you're right that the car's range may not have decreased as much as I think. But I've only got two things to go by -- Nissan's gauge and my driving experience.

So, if Nissan tests the car and says their gauge is wrong and I've got more range than indicated, should I ask the tech to make the missing battery capacity bar come back on again?

 

[edatoakrun]

="Randy3"
edatoakrun,

First, I want to say that I have enjoyed reading your posts. I'm not trying to be negative to you when I say that I'm just a driver.

But, a couple of thoughts. Probably everyone on our forum understands why we call the Distance to Empty gauge the "Guess-O-Meter". It's been inaccurate since the beginning. I *think* we're now understanding that the battery capacity meter is also inaccurate. I'm not quite there yet. It's easy for me to understand that I'm not getting the range that the Distance to Empty gauge shows. But the battery capacity meter is different. I don't understand electricity (and electronics?) well enough to realise that Nissan has again provided us with a gauge that I might as well cover over with black tape. Is the number of bars showing on the battery capacity meter bogus?...

Not "bogus", but so uncertain that it is almost useless, IMO.

Capacity bar losses, like gid counts, and dash, nav screen m/kwh and Carwings kWh use reports, all now seem likely to have uncertainties on the order of +/- somewhere near 10%, apparently strongly correlating to the individual LEAF's history of battery temperature. So the capacity bars are almost useless data sources, IMO, in calculating the actual capacity loss of any LEAF.

And even assuming the first bar is intended to represent 15% of capacity, is that 15% of the total battery capacity or 15% of the (possibly variable) percentage of the battery we can access between "100%" and shut-down?

And there is at least one further variable, how variable battery capacity at temperature, which we (most of us, anyway) have no way of accurately measuring, correlates to the factors above.

="Randy3"

Then there is your previous post, responding to my notification that I called Nissan to get a case number for battery capacity (losing a bar). Your post didn't just say to do a simple test drive. It talked about environmental conditions, etc. That's what brought out my comment about not operating a test facility. Your comment here makes more sense to me, just to a drive that I've done before, in a similar manner, and compare the results. Thanks for clarifying. Okay, I've done that. My daily drives are often very similar. But I've also done a route to the San Jose area several times. It's 72 miles from my house to a KOA Campground just west of Los Banos, CA (a favorite charging point). The last time I made that drive the car hit VLB before reaching Los Banos. When I first drove it (approximately April 2011), it hit VLB just before the KOA. It's about a 13 mile difference. Based on this, I no longer feel comfortable making this trip in the LEAF. (BTW, I'd love to have some L2 EVSE's along this route, maybe in Los Banos.)...

The problem is a "13 mile difference" does not have much meaning in terms of capacity difference, unless every mile is driven at the same constant m/kWh, and both test runs normalize all the other variables as much as practicable.

="Randy3"
edatoakrun, you're right that the car's range may not have decreased as much as I think. But I've only got two things to go by -- Nissan's gauge and my driving experience.

So, if Nissan tests the car and says their gauge is wrong and I've got more range than indicated, should I ask the tech to make the missing battery capacity bar come back on again?

Well, the only reset done, AFAIK (TickTock's from Three to one bar loss) seemed to largely correct the error.

However, IMO, the more effective approach would be for us to be addressing the issue of the inaccurate kWh use reports complied by our LEAFs, reported by Carwings, and which are also used to calculate the inaccurate m/kWh reports we are (apparently) all seeing from the dash and nav screen.

I have filed a complaint with Nissan.

But Nissan has said very little, either to me or publicly, about when or if they intend to fix our "gauge error" problems.

IMO, this might be because Nissan prefers the present speculation about capacity loss (even the overblown hysteria on this forum) to actually giving us the tools they promised us, and we paid for, to accurately determine our available battery capacity.

 

[surfingslovak]

Do you generate a singularity in you Leaf every time you switch to ECO mode?

I do! Why?

Is your range the same over the entire multiverse, even if you didn't drive in all of them that day?

My range seems to adhere to Heisenberg's uncertainty principle. Instruments and observation won't help here.

Do you approach the event horizon at the same arcminute and arcsecond every time you drive to work?

Certainly, and it's easy for me, since I'm an autist with nearly photographic memory.

Do you harness the same amount of dark energy and use the Hubble Constant when you regen?

Hey, that's proprietary information.

That type of standard is unrealistic (allowing for an exception in possibly ONE of the multiverses).

You should see the standards I imposed in MY universe. Colicky armchair quarterbacks don't exist there. Can't tell you what relief that is.

 

[edatoakrun]

...You should see the standards I imposed in MY universe. Colicky armchair quarterbacks don't exist there. Can't tell you what relief that is.

You don't exist in your own universe?

That must be a real relief to you...

 

[surfingslovak]

You should see the standards I imposed in MY universe. Colicky armchair quarterbacks don't exist there. Can't tell you what relief that is.

You don't exist in your own universe?

That must be a real relief to you...

I don't think that I aimed that comment at anyone in particular, Ed. But if you must, please be my guest.

 

[edatoakrun]

You don't exist in your own universe?

That must be a real relief to you...

I don't think that I aimed that comment at anyone in particular, Ed. But if you must, please be my guest.

If you'd like to make a substantive comment, please explain how you determined that your LEAF was "down 10%".

Edit- from the recharge capacity as shown here?


https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dG9vbzBiMW8tc1c2UzFKM3RiUG5ORHc#gid=0" onclick="window.open(this.href);return false;


As I commented at the top of this page, AFAIK, there is even less ability to asses capacity loss with any accuracy at that relatively low level, than there is with LEAFs having a greater percentages of capacity loss.

="surfingslovak"

...I was down 10%, which made the Leaf less practical for my needs. Since the car was owned, and not leased, it had to go at some point. Driving the ActiveE exclusively for now.

http://www.mynissanleaf.com/viewtopic.php?f=27&t=9529&start=210" onclick="window.open(this.href);return false;

Good luck with the ActiveE.

Or at least, better luck than you've had so far...

 

[surfingslovak]

Please explain how you determined that your LEAF was "down 10%". Edit- from the recharge capacity as shown here?

Yes, that's one of the things I measured. Sorry, but I see no reason why I should submit myself to your inquisition again.

Good luck with the ActiveE. Or at least, better luck than you've had so far...

Thanks. I hope your comment was sincere.

 

[RegGuheert]

GIDs at 100% charge

5/2012 (one bar lost): 228
6/30/2012 (two bars lost): 213
7/22/2012: 215
9/21/2012: 213
10/23/2012: 217
11/5/2012: 220

Thanks for the update! That is some major leveling off!

 

[Joeviocoe]

GIDs at 100% charge

5/2012 (one bar lost): 228
6/30/2012 (two bars lost): 213
7/22/2012: 215
9/21/2012: 213
10/23/2012: 217
11/5/2012: 220

Thanks for the update! That is some major leveling off!

Does this mean you will regain that second lost bar this winter?

How many Leafs have regained a lost bar?

Thanks.

 

[turbo2ltr]

I haven't heard of anyone getting a bar back without intervention from Nissan. It will certainly be interesting to see. Though the algorithm that calculates capacity may assume capacity will always decrease...

 

[DaveinOlyWA]

GIDs at 100% charge

5/2012 (one bar lost): 228
6/30/2012 (two bars lost): 213
7/22/2012: 215
9/21/2012: 213
10/23/2012: 217
11/5/2012: 220

Thanks for the update! That is some major leveling off!

Does this mean you will regain that second lost bar this winter?

How many Leafs have regained a lost bar?

Thanks.

funny thing about regaining lost GID... that seems to be common but what isnt (at least not yet) is gaining back lost range