Capacity Loss on 2011-2012 LEAFs

[edatoakrun]

My percentage loss of capacity - my Lincomatic Gid meter and the capacity bars aside - is backed up by the actual decrease in range that I have experienced. Both track fairly close to each other making me believe that the capacity loss is real and fairly accurately portrayed.

If the variations in indicated capacity loss are largely dependent on climate, as appears to be the case, and IF cooler climate LEAFs are also under-reporting capacity loss by gid count, by CarWings kWh, dash, and nav screen m/kWh (and capacity bar losses, when those begin to occur) even as hot climate LEAFs are over reporting capacity loss from those sources, then there would presumably be many LEAFs with "Goldilocks" climate exposure where the actual loss and all the "gauges" should match up pretty well.

That may be the case with your LEAF. Do you have a recharge test that tends to confirm it?

 

[TomT]

I'll run it down to LB or VLB next week and do one then.

That may be the case with your LEAF. Do you have a recharge test that tends to confirm it?

 

[RegGuheert]

="RegGuheert ...If these recharge tests were following the same drive, why do you think the recharge time has decreased? Slightly improved driving efficiency (but not nearly as much as the instruments are telling you)?

I think my recharge time has decreased because I have lost some capacity. I just don't think you can say "6%" with any precision, more like ~6%, +/- ~4%.

If the test was to drive a particular course and then time how long it takes to recharge the battery after your drive, then the capacity of your battery has nothing to do with your recharge time. The wind, tire pressure and the efficiency of the driver and the drivetrain are the main determinants. In fact, if the battery has lost some capacity, then there is normally an associated increase in battery resistance, which would tend to increase the energy used during the drive and wasted during the recharge and would therefore tend to increase the recharge time, but only by a small amount.

That's why I think checking recharge times for LEAFs with multiple bar losses, and also LEAFs whose drivers suspect significant capacity loss for other reasons, could be a simple step that might be very informative.

I may give it a try, but I think as a test it should be done exactly from a "known" starting point such as shutdown, turtle, VLBW or LBW. Unfortunately, if the instruments are off by as much as you are indicating here (and I'm not saying they aren't), then some of these "known" points may really be unknowns.

Can you tell me the method you use to time a recharge? Is it with the CarWings messaging?

 

[Joeviocoe]

Well it happened. Add me to the 2nd Bar loss table. 20,651 mileage. got up today and now its gone. cars not even 2 yrs old. I will call Nissan and report the next bar loss. this doesnt bode well for 20% loss in 5yrs or 70% loss in 10yrs. come on Nissan step up and correct this.

Added to the tracking wiki.

==============================================================

You've had the Leaf for about 19 months... and Nissan had put about 3,000 miles before you bought it... so just about 2 years cycle life. And calendar wise, the car was manufactured in May 2011. So just about 2 years.

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

For Tyler, TX
... 86.2% SOC @ 2 years
82.6% SOC @ 3 years
76.2% SOC @ 5 years
62.5% SOC @ 10 years
7.1 years *End of life* @ 7 years.

Question for the group:

Is it still accurate to say (after the firmware upgrade):
That the 1st bar is 15% of SOC and each subsequent bar is 6.25% of SOC ???

 

[mksE55]

Well it happened. Add me to the 2nd Bar loss table. 20,651 mileage. got up today and now its gone. cars not even 2 yrs old. I will call Nissan and report the next bar loss. this doesnt bode well for 20% loss in 5yrs or 70% loss in 10yrs. come on Nissan step up and correct this.

Added to the tracking wiki.

==============================================================

You've had the Leaf for about 19 months... and Nissan had put about 3,000 miles before you bought it... so just about 2 years cycle life. And calendar wise, the car was manufactured in May 2011. So just about 2 years.

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

For Tyler, TX
... 86.2% SOC @ 2 years
82.6% SOC @ 3 years
76.2% SOC @ 5 years
62.5% SOC @ 10 years
7.1 years *End of life* @ 7 years.

Question for the group:

Is it still accurate to say (after the firmware upgrade):
That the 1st bar is 15% of SOC and each subsequent bar is 6.25% of SOC ???

This is what makes it sad, was on the dealer lot for about 4-5 months. they put about 3,000 miles on it. purchased 10/11 so less than 500 miles a month. I put 9000 more and at 11,000 miles lost a bar. in less than 1 yr of ownership. 15% in 1 yr is awful and I was protecting the battery fewer charges, only over night to 80@ most of the time. mileage went from about 70 miles at 3.9 mkh to 55miles at 3.9 mKh. Worse in the winter. so now we are less than 2 yrs. not 2 yrs of driving and I have put about 17,000 miles on the car in about 17 months of use. Now with about 78.75% of the battery left. My range is significantly reduced. 50-55miles with careful driving and a warm batter 5-6 bars or it want make 45 miles before LBW if cold. This car is now 5 miles from being useful to me as a daily driver. I plug in every night now and have to charge to 100% to be able to use the car. no unforeseen errands. I leased thank the Lord and will start the return process or trade in. Sorry Nissan got this close to a very nice electric car but it seems hot climate areas degrade to fast. I was even hoping for maybe 10% a yr worst case and now its over 10% yearly and with the increase charging schedule it will degrade faster. sometime now I have to charge 3x in a day on days where I need to go 70-80 miles in 1 day.

 

[TonyWilliams]

Nissan doesn't have (to my knowledge) updated firmware to change the capacity bars, so if you've lost two, the official number of capacity is:

15% + 6.25% = 21.25% lost

Capacity is therefore 72.5% - 78.75%

But, honestly, as we learned in Phoenix, you may be somewhat above that value in real world losses.

 

[edatoakrun]

="RegGuheert" Can you tell me the method you use to time a recharge? Is it with the CarWings messaging?

Yes.

="RegGuheert"

I think as a test it should be done exactly from a "known" starting point such as shutdown, turtle, VLBW or LBW. Unfortunately, if the instruments are off by as much as you are indicating here (and I'm not saying they aren't), then some of these "known" points may really be unknowns.

Of course any recharge test, whether timed or metered, must be from the same indicated discharge point.

All the results I have posted are from ~VLBW, which I consider the lower limit of my usable available capacity. And as I posted previously, the reductions in both range (as tested on a single ~87 mile course, and then adding additional miles at the end to bring my capacity down to VLBW.) and in recharge capacity, as measured by time of charge on 16 A/240 V from ~VLBW to "80%" are both consistent with relatively small capacity loss over the last 20 months.

Since many LEAFers do not want to do range tests, and do not have accurately metered 240 V chargers, I suggested they try the time to "80%" method to try to get a rough idea of their actual capacity loss, rather than rely on the "15%" figure for the for the first capacity bar loss, and "6.25%" for the second, which have been proven to have little relationship to reality, at least in "hot" climate LEAFS.

Since I have had updated and functional CW since only a few months from delivery, I have always been able to calculate my nominal kWh used (the kWh reported by CarWings, and displayed on the nav screen in m/kWh using the correct odometer miles, and displayed on the dash in m/kWh with the ~2.5% error in miles driven) and my kWh remaining, with accuracy to within a few hundred Wh, simply by dividing my odometer miles driven my the m/kWh on the nav screen, using the nominal total kWh available, as determined by previous range/capacity tests, as adjusted for battery temperature while charging.

So I have never had a LBW or VLBW that was unplanned, and I have never driven more than a few hundred Wh past the VLBW. I know that I have some unknown capacity past that point, and I can't determine whether that kWh has varied since delivery. But since I can meet all my range requirements without using that capacity, and I expect I may extend my battery life by reserving that capacity for emergency use, I don't care very much.

As I posted previously, my LEAF's, nominal kWh from VLBW to "100%" is currently ~15.6 to ~16 kWh from "100%" to VLBW, at temperatures between ~30 F to ~50 F, and this has been relatively stable (adjusted for battery temperature) for the last several months, after initially dropping rapidly from 18.7 kWh at ~80 F in my first range capacity test on this route, in September of 2011.

I have no idea if this stability will remain once the weather heats up. I got my first 6 temp bars of this year (other than in my BAY area trip where I could warm my battery with DC charges) last Friday, at the very end of a ~69 mile 11 bar to LBW trip in ambient temperatures of ~80F.

On my ~690 mile road trip to the San Francisco Bay Area last week (which I hope to write up a complete report on when I get the time) I drove four 80+ mile trips from "100%", three times to past the LBW. The three of these trips where I went past LBW, (14.9 nominal kWh use being the highest, after a ~84.8 mile slow drive with ~1,200 ft net ascent!) all indicate my LEAF still has very close to 15.6 to 16 kWh nominal from "100%" to VLBW, at the ~30 F to ~50 F battery recharge temperatures, that I have had since the start of this year. Below is the entire record to date.

Below is how Carwings has reported the total energy use from "100%" to ~VLBW on my warm climate LEAF two years from the factory and with ~16,000 miles on the odometer.

While the reported kWh use has dropped quite a bit, My LEAF has displayed no significant loss of range from my first test, to most recent, on range tests of 95-113 miles, when corrected for all test variables, including speed, temperature both when charging and when driving, and my own driving efficiency (as reflected in the regen kWh reported by CarWings).

Of course my battery has lost capacity in the last 18 months, it just not yet a large enough loss to show up clearly in a range test, and is, IMO, nearly certainly far less than the kWh use results below, showing capacity loss approaching 15% just over the last 18 months (when adjusted for battery temperature) would indicate:

All charges prior to testing were to “80%", battery allowed to return to ambient temperature, and then charged @ 16 A 240 V to “100%”, two to three hours before range/capacity test begins, and then left plugged into the EVSE until departure.

IMO The distance driven at the point where the battery temp bars increased, when that has occurred, is useful data as to the relative battery temp and temperature the (temperature variable) battery capacity when the "100%" charge was completed.

9/7/11 18.7 kWh from "100%" to VLBW, 6 dash battery temp bars constant (as recalled later)

5/10 12 17.2 kWh, 5 to 6 temp bars ~mile 73

5/31/12 17.5 kWh, 5 to 6 temp bars ~mile 5

6/17/12 17.5 kWh, 6 temp bars constant

8/18/12 17.0 kWh, 6 temp bars constant

8/30/12 16.8 kWh, 6 temp bars constant

9/08/12 16.7 kWh, 5 to 6 temp bars ~ 4.6 miles

10/1/12 16.6 kWh, 6 temp bars constant

11/3/12 16.2 kWh, 4 to 5 temp bars ~mile 14

1/31/13 15.7 kWh, 4 to 5 temp bars ~mile 24

2/16/13 15.8 kWh, 4 to 5 temp bars ~mile 18

3/1/13 15.6 kWh, 4 to 5 temp bars ~mile 18

3/13/13 16.0 kWh, 5 bars temp constant


I think it is nearly certain, that the LEAF "gauge error" that has shown up in premature battery capacity bar loss and Wh/gid error in other LEAFs is also displaying itself in the dash and nav screen m/kWh, and also in the (more accurate) CarWings kWh use reports, from my LEAF, as I have posted above.

IMO, any LEAFer who can learn to use CarWings, may see the same sort of results I have, and also be able to largely differentiate any range loss due to real battery capacity loss, from their LEAF's questionable kWh use reports, as I believe I have been able to do.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=9195&start=30" onclick="window.open(this.href);return false;

 

[Stoaty]

Well it happened. Add me to the 2nd Bar loss table. 20,651 mileage. got up today and now its gone. cars not even 2 yrs old. I will call Nissan and report the next bar loss. this doesn't bode well for 20% loss in 5yrs or 70% loss in 10yrs. come on Nissan step up and correct this.

A few questions:

1) Was the Leaf left at 100% charge for long periods of time before you got it?
2) How often do you leave the Leaf at 100% charge and for how long?
3) What is your average efficiency in miles/kwh from the dash?
4) How many days a week do you park in the sun?
5) Do you run the Leaf down below LBW or VLBW often?

From the information we have, your Leaf appears to be right on schedule for your part of the country. Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states). That is because the capacity bars appear to have a systematic bias of slightly over reporting capacity loss. If you have access to a Gid meter, it would be useful to know your Gid readings at full charge and 80% charge.

 

[TimLee]

Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states). That is because the capacity bars appear to have a systematic bias of slightly over reporting capacity loss.

Stoaty,
Could you provide further details on this, or links to the documentation of this?
Your statement and TonyWilliams statement above disagree. :?

 

[Stoaty]

Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states). That is because the capacity bars appear to have a systematic bias of slightly over reporting capacity loss.

Stoaty,
Could you provide further details on this, or links to the documentation of this?
Your statement and TonyWilliams statement above disagree. :?

It's all documented in the Wiki:

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

Note that in Tony's range test % capacity based on Gids was overly pessismistic in every single case. Be sure to read the section on Nissan's testing also:

http://www.mynissanleaf.com/wiki/index.php?title=Battery_Capacity_Loss#Nissan.27s_Responses_and_Actions" onclick="window.open(this.href);return false;

 

[LEAFfan]

I firmly believe that losing the first CB on a '11/'12 is a 20% loss in capacity, not 15%. Two reasons:
The BCM and Gid meter read 80-81% after a one bar loss, but 98-100% when new (on some cars here).
When it was new, I could easily drive 100 miles on an 80% charge. After losing a CB, I could only drive 80 miles or less on a 100% charge (same m/kW h and same route with same conditions).

 

[Joeviocoe]

Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states). That is because the capacity bars appear to have a systematic bias of slightly over reporting capacity loss.

Stoaty,
Could you provide further details on this, or links to the documentation of this?
Your statement and TonyWilliams statement above disagree. :?

I guess there is still an active debate on this?

 

[Stoaty]

I firmly believe that losing the first CB on a '11/'12 is a 20% loss in capacity, not 15%. Two reasons:
The BCM and Gid meter read 80-81% after a one bar loss, but 98-100% when new (on some cars here).
When it was new, I could easily drive 100 miles on an 80% charge. After losing a CB, I could only drive 80 miles or less on a 100% charge (same m/kW h and same route with same conditions).

While that could be the case for your individual Leaf, the data in Tony's range test directly contradict that statement for a group of Leafs that were carefully tested.

 

[planet4ever]

Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states).

What manual? There were 15% and 6.5% numbers in the very first edition of the 2011 Service Manual, but they were removed for the second edition a few months later. Have those numbers ever appeared anywhere else?

Ray

 

[Stoaty]

Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states).

What manual? There were 15% and 6.5% numbers in the very first edition of the 2011 Service Manual, but they were removed for the second edition a few months later. Have those numbers ever appeared anywhere else?

That's the manual I am talking about. Direct from Nissan, and while they removed it from the manual, they never contradicted it during the firestorm about early capacity loss.

 

[planet4ever]

So, what you meant to say was, "(not the 21% the Service Manual used to state.)" In fact Andy said in Phoenix that the capacity bars were "pessimistic". I took that as meaning their computer program wasn't calculating them correctly. It is my suspicion that is the real reason why the numbers were removed from the Service Manual, even though the numbers originally published were what they intended for the bars to mean. Based on the variability we have seen reported it may be that the capacity bar calculating program is no more precise than the Distance to Empty (i.e. GOM) calculating program. Both of them are running in that same dash control computer, may have been created by the same programmer, and could even share some subroutines.

Ray

 

[surfingslovak]

Please have a look at the table Tony compiled after the range test. I believe that the largest discrepancy between the loss implied by the capacity gauge and determined by the test was about 15%. The GOM on a 2011 LEAF will overestimate the true range of the vehicle by about 30% after a full charge. This assumes consistent urban driving at relatively low speeds. When the GOM reaches single digits, it will underestimate the true remaining range by about 50%. It can be relatively accurate around 50% SOC, but only if the effects of terrain and weather are negligible.

While the capacity bar gauge is clearly a bit pessimistic, it is consistently so, and does not suffer from wild and erratic behavior like the GOM would. While I appreciate what you meant to say, I would not go as far as stating that the capacity gauge is no more accurate than the GOM. I don't think that would be fair. Especially not to the people that suffered real range loss. Many have learned to ignore the GOM. I think ignoring the capacity gauge the same way would not be prudent. We will likely never know why the reference to this gauge has been removed from the manual. If you don't mind me asking, why is this so important?

I would hope that the details of the new warranty will be announced soon, along with a clear description of the capacity gauge and its accuracy, since Nissan has chosen to use it as a point of reference for the warranty. Perhaps that will help settle these debates.

Note that Blue534 achieved lower range than indicated, and the value was later corrected.

 

[planet4ever]

While the capacity bar gauge is clearly a bit pessimistic, it is consistently so, and does not suffer from wild and erratic behavior like the GOM would. While I appreciate what you meant to say, I would not go as far as stating that the capacity gauge is no more accurate than the GOM. I don't think that would be fair. Especially not to the people that suffered real range loss. Many have learned to ignore the GOM. I think ignoring the capacity gauge the same way would not be prudent. We will likely never know why the reference to this gauge has been removed from the manual. If you don't mind me asking, why is this so important?

Your points are very good. I should not have suggested that the capacity gauge was as erratic as the GOM. Actually I said "may be", but even that was far too strong. And I certainly don't want impugn those who have had real and significant loss.

As to why I took this position, I often find myself peeved by those who try to ascribe evil motives to Nissan for the things they do. I doubt seriously that they removed the table from the Service Manual because they were trying to hide the truth from us. On the other side of the coin, the 15% + 6.5% mantra seems to have become gospel here, even though it is not in any published manual, and has not been for more than two years.

Ray

 

[Herm]

Nissan, with their "not yet official" warranty implies 3 CB loss is pretty near to 30% battery degradation, the accepted number for a dead lithium-ion battery.

 

[mksE55]

May want to add my New Case number for the 2nd bar loss. 110-69616

as for your questions.

Well it happened. Add me to the 2nd Bar loss table. 20,651 mileage. got up today and now its gone. cars not even 2 yrs old. I will call Nissan and report the next bar loss. this doesn't bode well for 20% loss in 5yrs or 70% loss in 10yrs. come on Nissan step up and correct this.

A few questions:

1) Was the Leaf left at 100% charge for long periods of time before you got it?

suspect dealer left if fully charge every chance he could so anyone could test drive it with out worries . it was fully charged every test drive i took in it the 2 months I was looking at it.


2) How often do you leave the Leaf at 100% charge and for how long?

charge at night to 100% now I have to or I cannot drive the car daily. usually fully charged by midnight driving to work around 6 am

3) What is your average efficiency in miles/kwh from the dash?

usually run 3.8-4.0 this gets me about 50-55miles and sitting on LBW
4) How many days a week do you park in the sun?

garage at night. mon-fri at work all day outside

5) Do you run the Leaf down below LBW or VLBW often?
I try not to end up at LBW but now hit it about 2-3x week. VLBW 2-3 amonth. I am not stupid enough to want to walk in the Texas heat.
I dont think my car is on schedule, if this was the schedule and Nissan knew it. This is a failure. I understand there is some range past zero on the dash but who want to drive just wondering when you will have to start walking. I can some increase lost already from last year since now with the AC or heater I hit LBW almost everyday I use those and never did in the past.

From the information we have, your Leaf appears to be right on schedule for your part of the country. Remember that from Nissan's testing and the range test, loss of 2 capacity bars means a loss of about 15% capacity (not the 21% capacity the manual states). That is because the capacity bars appear to have a systematic bias of slightly over reporting capacity loss. If you have access to a Gid meter, it would be useful to know your Gid readings at full charge and 80% charge.

I didnt know someone else had better information than the manual for battery loss. Is this posted by Nissan. I suggest my loss is greater than 21.75% but I dont know how much battery is available below the dash marks and really dont want to find out. the one time I creeped it home at 30mph past zero was 6 miles and I was glad it was mostly downhill. at least I could ride the brakes. I have been out of the loop for the last few months. can some one point me to the info about this new battery warranty coming. I did hear about warranty if you have lost more than 3 bars. they will replace your pack back to 80% battery.