Capacity Loss on 2011-2012 LEAFs

[RegGuheert]

But if the car still drives exactly like it did when it was new 2 years ago, why should I care about a hypothetical loss?

Your car wasn't even created two years ago. You have only owned it about one week beyond 18 months.

Looks like around 10% capacity loss to me.

6.4 mi/kWh * 21 kWh = 134.4 mi on a new LEAF.

OE got to 102.1 mi somewhere between LBW and VLBW. For the sake of the argument, let's assume LBW since that improves the number. At LBW a LEAF still has 17% capacity remaining, so he could have driven 17% further or 120 mi before turtle. That is about 10% short of 134 miles.

And I will point out that submission was before the summer and some 8000 miles ago. There will have been further degradation since then.

 

[ALLWATZ]

The only option Nissan has offered has been to buy back the car.

Not sure where your getting this info, you make it sound like it just an option to check off on a peice of paper. Nissan is being forced to buy back the car and has done so in only a very few instances. They aren't willingly offering it at all.

 

[DaveinOlyWA]

The only option Nissan has offered has been to buy back the car.

Not sure where your getting this info, you make it sound like it just an option to check off on a peice of paper. Nissan is being forced to buy back the car and has done so in only a very few instances. They aren't willingly offering it at all.

have they? i cant help but think that some wanted their packs replaced instead of a buy back. was that an option for anyone who returned their LEAF? i am thinking it was not offered

 

[ZE1]

The only option Nissan has offered has been to buy back the car.

Not sure where your getting this info, you make it sound like it just an option to check off on a peice of paper. Nissan is being forced to buy back the car and has done so in only a very few instances. They aren't willingly offering it at all.

have they? i cant help but think that some wanted their packs replaced instead of a buy back. was that an option for anyone who returned their LEAF? i am thinking it was not offered

Why would they want their pack replaced? If they owned for their car through 2 hot climate summers and have problems with their pack now. If they got a new pack now, how would that help them 2 or 3 summers down the road when history repeats itself?

On an unrelated note to my comment above, the thread has gotten a bit quiet with the cooler weather, less reports of lost bars with the hotter months behind us. Thank you fall/winter.

 

[mark1313]

Im going to hate see what happens next summer..Losing 2 bars in one month did not make me very happy...
I find my self charging the car more frequently and also to 100% ..This means the batteries will be in worst shape next summer..I feel like the Leafs will be in a test tube all winter long with more bad results coming out in the heat next summer...
Anyone know how someone gets on the witness stand in the lawsuits against Nissan,as soft as I drove the Leaf (6.1 M/KW life time) ,I did not expect the drastic battery capacity loss ...

 

[DaveinOlyWA]

Im going to hate see what happens next summer..Losing 2 bars in one month did not make me very happy...
I find my self charging the car more frequently and also to 100% ..This means the batteries will be in worst shape next summer..I feel like the Leafs will be in a test tube all winter long with more bad results coming out in the heat next summer...
Anyone know how someone gets on the witness stand in the lawsuits against Nissan,as soft as I drove the Leaf (6.1 M/KW life time) ,I did not expect the drastic battery capacity loss ...

i am sure rates of degradation will slow down but also sure the rate wont slow down enough to keep owners satisfied. One can only hope that the winter will give Nissan enough time to address the issue with a viable solution other than "just lease it"

Just as important will be getting some battery pack pricing. Favorable pricing for any existing LEAF owners who are under a certain mileage is something i think appropriate (want 100,000 miles hoping for 75,000...)

there is a real value for degraded packs even ones that have lost 30% so sure a "new" pack might be spendy but the exchanged pack should (for us anyway) take a good chunk off the bill

 

[edatoakrun]

...the thread has gotten a bit quiet with the cooler weather, less reports of lost bars with the hotter months behind us. Thank you fall/winter.

Actually, bar loss reports have not slowed down, they seem to have stopped altogether.

There has not been a single report of a capacity bar loss Since October 12, and there seems to be only two bar losses reported from Arizona in the last eight weeks. IMO, this is indicative of the bar loss being far more accurate as an indication of long term high temperature exposure, than of actual battery capacity loss. If capacity bars actually represented the fixed percentage of capacity, as the Wiki (incorrectly, IMO) reports, I think we should have seen continued reports of bar losses, particularly from Arizona, where daily high temperatures in the 85-90 F range continued well into November.

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

Unfortunately, we still don't have much information about the actual loss of capacity of LEAFs in all climates, IMO since the hysteria that resulted from the inaccurate capacity loss indications from bar loss and gid counts, seems to have inhibited most serious efforts to monitor capacity loss be either range tests or recharge capacity observations, by MNL members.

 

[leafwing]

Actually, bar loss reports have not slowed down, they seem to have stopped altogether.

Am'I dreaming or did you really and finally admit that high temperature influences battery capacity and performance?

 

[edatoakrun]

Actually, bar loss reports have not slowed down, they seem to have stopped altogether.

Am'I dreaming or did you really and finally admit that high temperature influences battery capacity and performance?

You obviously are hallucinating if you actually believe that I ever did not "...admit that high temperature influences battery capacity and performance".

I knew this to be the case long before I got my LEAF, and it was an very important consideration in both my initial decision to lease (and later, to buy) my LEAF, given the hotter-than-average peak temperatures (up to ~110 in the Summer) where I drive my LEAF.

I could have been close to losing a capacity bar last Summer (as indicated by frequently seeing nine charge bars after "80%" charging) whatever that might actually indicate of either capacity loss or BMS operation, but I have seen no significant loss of range or capacity, from the time I began range tests 14+ months ago, with ~3,300 miles on my odometer.

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

Still no significant loss of range (adjusted for battery and driving temperature) over the last 14 + months and ~10,800 miles (~14,100 miles total as of today) as best as I can tell. I expect I actually do have some capacity loss over this time, just not enough to be "heard" above the above the "noise" from the several significant uncertainties of my range and recharge tests.

I will expect I will clearly see capacity loss it in the next year or so, and will report it, when it happens.

 

[DaveEV]

Still no significant loss of range (adjusted for battery and driving temperature) over the last 14 + months and ~10,800 miles (~14,100 miles total as of today) as best as I can tell. I expect I actually do have some capacity loss over this time, just not enough to be "heard" above the above the "noise" from the several significant uncertainties of my range and recharge tests.

I don't see any wall-charge-energy data in your tests. Did I overlook it?

 

[edatoakrun]

Still no significant loss of range (adjusted for battery and driving temperature) over the last 14 + months and ~10,800 miles (~14,100 miles total as of today) as best as I can tell. I expect I actually do have some capacity loss over this time, just not enough to be "heard" above the above the "noise" from the several significant uncertainties of my range and recharge tests.

I don't see any wall-charge-energy data in your tests. Did I overlook it?

Yes, but, unfortunately, I only have the energy results as L2 time to to "80%", from my earliest test, so I can't produce that data with any more precision than I did on the thread below.

Like most everyone else, until this Summer, I thought the dash and Navscreen m/kWh reports, and CW kWh use and m/kWh (after the CW upgrade) were dependable (or at least, consistent) so I thought that the wall-charge energy (due to unknown charge efficiency) was probably a less accurate measure of kWh use, and I did not attempt to record it consistently.

IMO, since others now seem to have seen similar results as mine RE m/kWh report inaccuracy, "from the wall" information is really the only reliable data (other than total range from a normalized test) for assessing battery capacity, although both are still subject to significant uncertainties.

BTW, I have a "hybrid" result from my most recent test, combining time-of-charge at L2 and final charging at 120 volt measured by a kill-a-watt, that I need to write up and post. Feel free to comment on the thread below, about this, or any other aspect of the topic.

...I did not meter my charge a year ago, but I did record the charge time, and also got an accurate 16 amp 240v recharge time on 9/8/12. It took 4 hours and 16 minutes to reach 80% (and another one hour and 11 minutes to reach “100%”) following this trip.

Assuming a 3.75 kWh/h draw from my 16 a modified Panasonic charger, and the 16.7 total capacity from VLBW to 100% charge, I believe that this would indicate a charging efficiency from ~VLBW to the “80%” level of ~96%, which is implausible, in light of all reports of charging efficiency by others.

This compares to a recharge time of ~4 hours 25 minutes to reach “80%” following my first range test, on 9/7/11, with a reported 18.7 kWh used from 100% to about the same capacity level, ~VLBW....

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

 

[DaveEV]

Like most everyone else, a year ago I thought the dash and Navscreen m/kWh reports, and CW kWh use and m/kWh (after the CW upgrade) were dependable (or at least, consistent) so the wall-charge energy (due to unknown efficacy) seemed to be a less accurate measure.

IMO, since others now seem to have seen similar results as mine RE m/kWh inaccuracy, "from the wall" information is really the only reliable data (other than total range from a normalized test) for assessing battery capacity, although both are still subject to significant uncertainties.

I don't think that anyone besides you has believed CARWINGs data to be reliable enough to discern reliable data from. Certainly not without multiple data points to eliminate error. And certainly it's impossible to compare data before/after the NTB that corrected CARWINGs data.

BTW, I have a "hybrid" result from my most recent test, combining time-of-charge at L2 and final charging at 120 volt measured by a kill-a-watt, that I need to write up and post. Feel free to comment on the thread below, about this, or any other aspect of the topic.

All a "hybrid" result does is increase the types of errors that can affect readings and there are way too many other assumptions being used. For certain, while L2 time to 100% may be used to approximate energy consumed, in my experience the amount of time spent tapering power before shutting off varies too much to rely on time alone.

 

[edatoakrun]

Like most everyone else, a year ago I thought the dash and Navscreen m/kWh reports, and CW kWh use and m/kWh (after the CW upgrade) were dependable (or at least, consistent) so the wall-charge energy (due to unknown efficacy) seemed to be a less accurate measure.

IMO, since others now seem to have seen similar results as mine RE m/kWh inaccuracy, "from the wall" information is really the only reliable data (other than total range from a normalized test) for assessing battery capacity, although both are still subject to significant uncertainties.

I don't think that anyone besides you has believed CARWINGs data to be reliable enough to discern reliable data from. Certainly not without multiple data points to eliminate error. And certainly it's impossible to compare data before/after the NTB that corrected CARWINGs data.

BTW, I have a "hybrid" result from my most recent test, combining time-of-charge at L2 and final charging at 120 volt measured by a kill-a-watt, that I need to write up and post. Feel free to comment on the thread below, about this, or any other aspect of the topic.

All a "hybrid" result does is increase the types of errors that can affect readings and there are way too many other assumptions being used. For certain, while L2 time to 100% may be used to approximate energy consumed, in my experience the amount of time spent tapering power before shutting off varies too much to rely on time alone.

You are really veering off topic, "drees" requiring me to do the same, to reply.

Have you had CW updated?

If so, why don't you post your informed opinion, on an appropriate thread, regarding CW accuracy or inaccuracy?

As I've mentioned innumerable times before, all my CW reports seem to precisely match the navscreen and dash reports of m/kWh (as corrected for odometer error) for all my driving results, not only as reported on all my range tests. I have no Idea why so many others can't seem to get over their Carwings-phobia, over 15 months since I first posted the results of the update, and asked some of the same questions we still have not resolved, to this date:

As I posted earlier, Since I had the Carwings update done on 8/3 (11), my Dash and Carwings miles/kWh numbers seem to match.

Even more interestingly, the daily Driving Records/electricity consumption now seem to accurately reflect the kWh delivered from my Modified L2, as best as I can calculate by recharge time.

Has anyone tried a 100% charge to Turtle discharge drive since having the update?

What total electricity consumption (kWh) did carwings report-and do you believe it to accurately reflect total battery capacity?

If you have a meter at the wall, what L2 charging efficiency percentage did it show for your recharge, using the Carwings energy consumption report?

http://www.mynissanleaf.com/viewtopic.php?f=31&t=5423" onclick="window.open(this.href);return false;

And as I've also posted many times before, IMO, it is not possible to measure capacity with a range test with optimum accuracy, without the driving efficiency data provided by the regen kWh reports provided by CW.

Yes, the time to "100%" from a L2 has uncertainties related not only to the "tapering" of the charge, but (almost certainly) due to capacity varying with battery temperature, and (possibly) also due to variation in the "100%" charge level allowed by the BMS.

The first of those uncertainties may be avoided by recording the recharge to 80% (as i did) which, AFAIK, has always been observed to be at a constant rate, and (according to Phil) to be to a consistent level as a percentage of total capacity.

I tried to normalize battery temperature during the recharge by charging at about the same time with the same overnight temperatures, to reduce the battery temperature variable as much as possible.

Does the LEAF have adaptive BMS, perhaps limiting "100%" charge levels following high temperature exposure, as some of the measured charge results posted by others seem like they might be indicating?

Not shown by my observations so far. But my LEAF may never have had it's battery heated long enough to a high enough temperature to clearly show adaptive BMS, and maybe I'll still see something in my future cold-weather testing this Winter, useful to that determination.

 

[myleaf]

Just wondering if anyone has recently lost their first bar or an additional bar.

 

[GRA]

I expect we'll see few if any until around April, when they'll start ramping up again. The deluge will probably arrive in June or July, as more cars hit their second summer. Of course, maybe we made enough noise early enough this year that sales have been retarded in areas most likely to suffer major degradation, but I expect the word didn't get out widely enough, soon enough. We can hope that summer 2014 won't see a similar avalanche of reports, if enough potential customers have been informed from this summer into next spring. Or maybe Nissan will finally do the right thing and stop advertising and selling the cars in unsuitable climates. Oh, I can dream. :roll:

 

[smkettner]

Has anyone ever regained a bar due to lower temps or other changes?

 

[leafwing]

Has anyone ever regained a bar due to lower temps or other changes?

I'm still waiting to regain the lost bar. :lol:

 

[Boomer23]

Has anyone ever regained a bar due to lower temps or other changes?

No, but I've regained Gids (see my sig below) and perhaps a couple miles of range (no actual range test, but trip range seems to have gone up about 2 miles).

 

[mwalsh]

Has anyone ever regained a bar due to lower temps or other changes?

No, but I've regained Gids (see my sig below) and perhaps a couple miles of range (no actual range test, but trip range seems to have gone up about 2 miles).

Mine have improved too - mid 250s for three mornings in a row this week so far. Best numbers since mid-July. Very happy to see that happen. May have been helped by running down further into the pack than I normally do - Monday I really hammered it on the drives to and from work, getting home with just 10.6%/50 Gids remaining.

 

[edatoakrun]

Has anyone ever regained a bar due to lower temps or other changes?

No, but I've regained Gids (see my sig below) and perhaps a couple miles of range (no actual range test, but trip range seems to have gone up about 2 miles).

Mine have improved too - mid 250s for three mornings in a row this week so far. Best numbers since mid-July. Very happy to see that happen. May have been helped by running down further into the pack than I normally do - Monday I really hammered it on the drives to and from work, getting home with just 10.6%/50 Gids remaining.

Colder batteries charged to the same percentage of total capacity should hold less kWh, is that in doubt?

So shouldn't we expect gid counts be declining as ambient battery temperatures decline seasonally?

In my 11/20 post on this page, I asked:

Does the LEAF have adaptive BMS, perhaps limiting "100%" charge levels following high temperature exposure, as some of the measured charge results posted by others seem like they might be indicating?

Anyone have an alternate explanation, if these higher gid counts are actually indicating greater kWh capacity, and not just variable (lower) Wh per gid?