Capacity Loss on 2011-2012 LEAFs

[WetEV]

All of our LEAFs have had their batteries lose a portion of their total capacity over these Winter months, but the lack of bar loss reports, IMO, offers clear statistical proof that the "gauge error" in the capacity bar reports is under-reporting the winter loss of battery capacity, just as capacity bars clearly over-reported capacity loss last Summer.

I don't think that follows.

Suppose capacity loss was accurately reported in cold weather, and over reported in warm weather. Wouldn't this show the same pattern? Suppose capacity loss was under reported in cold weather, and accurately reported in warm weather? Again, wouldn't this show the same pattern?

 

[edatoakrun]

All of our LEAFs have had their batteries lose a portion of their total capacity over these Winter months, but the lack of bar loss reports, IMO, offers clear statistical proof that the "gauge error" in the capacity bar reports is under-reporting the winter loss of battery capacity, just as capacity bars clearly over-reported capacity loss last Summer.

I don't think that follows.

Suppose capacity loss was accurately reported in cold weather, and over reported in warm weather. Wouldn't this show the same pattern?..

Again, if cold weather reports were accurate, I believe we would have seen many more bar loss reports over this winter (though less than in the Summer, of course) particularly from coastal regions, Florida (where the one bar loss report did occur, IIRC) and Hawaii where seasonal climate variations are minimal.

="WetEV

....Suppose capacity loss was under reported in cold weather, and accurately reported in warm weather? Again, wouldn't this show the same pattern?

Well, if the Cold weather bar loss reports were accurate, I'd think we might conclude that we are experiencing virtually no capacity loss over last Winter, which would be great if true, but seems implausible, IMO.

And the possibility that the Warm weather capacity bar losses are correct, seems to be contradicted by range tests, which fairly conclusively, IMO, showed warm weather bar loss reports have over-predicted the actual available battery capacity losses.

 

[WetEV]

All of our LEAFs have had their batteries lose a portion of their total capacity over these Winter months, but the lack of bar loss reports, IMO, offers clear statistical proof that the "gauge error" in the capacity bar reports is under-reporting the winter loss of battery capacity, just as capacity bars clearly over-reported capacity loss last Summer.

I don't think that follows.

Suppose capacity loss was accurately reported in cold weather, and over reported in warm weather. Wouldn't this show the same pattern?..

Again, if cold weather reports were accurate, I believe we would have seen many more bar loss reports over this winter (though less than in the Summer, of course) particularly from coastal regions, Florida (where the one bar loss report did occur, IIRC) and Hawaii where seasonal climate variations are minimal.

The following numbers are made up to explain my point. Suppose the hot weather loss is over reported by 5%, and the winter capacity is exact. In other words, if the car would have lost a bar at 15% if gauge was accurate, it would instead lose a bar at 10% in hot weather. In the cold weather, the bar loss is correctly and accurately at 15%. So if the car almost lose a bar in the summer at 9.9% loss, the car would need to drop to 15% loss to lose a bar in winter. So then with this pattern, there would many bars lost in summer, and none lost in winter.

All we can say from the lack of winter bar losses is that the summer reading is more pessimistic than the winter reading. Which of the two is more accurate isn't clear.

 

[mwalsh]

All we can say from the lack of winter bar losses is that the summer reading is more pessimistic than the winter reading. Which of the two is more accurate isn't clear.

The one thing to add back to the conversation again is that you don't get what you've lost back. If the car thinks you've lost 2 or 3 bars during summer hot weather...they are gone. Forever. Or at least until Nissan figures out and fixes what (if anything) is wrong. It would be another story entirely if you temporarily lost bars due to summer heat only to recover them once winter came. Many would still hate on it, period. But others would just hate on the summer and pine for a glorious long winter to arrive!

 

[edatoakrun]

As I mentioned before, if this were occurring, where there is NO winter (equatorial!) LEAFs would lose bars at a constant rate year-round, and, IMO, we would probably have seen (and maybe we soon will see, proving you correct) a higher distribution of Winter bar loss of occurrences in loss in like Hawaii, where the is very little "Winter".

There is also at least one report, IIRC, of a high mileage PNW LEAF that has capacity loss greater than 15%, but that still has 12 bars. Future reports from cooler regions might tend to contradict Nissan's many statements that the capacity bar "gauge error" is "pessimistic" in all circumstances.

IMO, it's a lot easier to see what bar loss is NOT- an accurate report of battery capacity, than to try to determine what exactly is causing what we seem to be seeing, the capacity bars disappearing prematurely in hotter climates, and during the Warmer months only.

WetEV wrote:
The following numbers are made up to explain my point. Suppose the hot weather loss is over reported by 5%, and the winter capacity is exact. In other words, if the car would have lost a bar at 15% if gauge was accurate, it would instead lose a bar at 10% in hot weather. In the cold weather, the bar loss is correctly and accurately at 15%. So if the car almost lose a bar in the summer at 9.9% loss, the car would need to drop to 15% loss to lose a bar in winter. So then with this pattern, there would many bars lost in summer, and none lost in winter.
All we can say from the lack of winter bar losses is that the summer reading is more pessimistic than the winter reading. Which of the two is more accurate isn't clear.

 

[LEAFfan]

There is also at least one report, IIRC, of a high mileage PNW LEAF that has capacity loss greater than 15%, but that still has 12 bars. Future reports from cooler regions might tend to contradict Nissan's many statements that the capacity bar "gauge error" is "pessimistic" in all circumstances.

I've tested many cars with my BCM (LEAF SGII), and ALL of them lost their first capacity bar around 80-81% which would be about 20% using the meter, 15% according to Nissan. So if that PNW LEAF used a Gid Meter to determine the loss, it explains why they haven't lost a CB yet. They won't lose one until the Gid Meter says about 80-81%, not 84-85%. And you can take that to the bank Ed.

 

[Volusiano]

I received a "we're not going to buy it back" letter from Nissan today after I started the BBB arbitration process. Strangely this arrived the day before I was going to mail the copies of everything the BBB requested I send in.

I got the same letter from Nissan. BBB is denying my claim as well, they say "you are not alleging a defect in materials or workmanship". I clearly stated in my letter that the battery is defective in hot climates. I sent in my appeal yesterday.

Pretty sure I will lose two more bars this summer. First and last Nissan I buy.

How many bars have you lost so far? 1 or 2?

I wonder if Nissan has ever accepted buyback on any 1-bar lost LEAF yet or not? Maybe you need to lose at least 2 bars?

I would wait until you lose your second bar and contact Nissan again with a new request.

If you already lost 2 bars and still got denied, I'd try to contact the local news and ask them to help ask Nissan why you got denied but others got approved. I remember one of the news stations in AZ has a program where they step in and contact the vendor on your behalf to help settle your dispute with the vendor. Ask them if they may want to do another news piece about how Nissan's buyback process is inconsistent and unfair.

 

[RegGuheert]

Again, if cold weather reports were accurate, I believe we would have seen many more bar loss reports over this winter (though less than in the Summer, of course) particularly from coastal regions, Florida (where the one bar loss report did occur, IIRC) and Hawaii where seasonal climate variations are minimal.

...

Well, if the Cold weather bar loss reports were accurate, I'd think we might conclude that we are experiencing virtually no capacity loss over last Winter, which would be great if true, but seems implausible, IMO.

And the possibility that the Warm weather capacity bar losses are correct, seems to be contradicted by range tests, which fairly conclusively, IMO, showed warm weather bar loss reports have over-predicted the actual available battery capacity losses.

Loss of capacity in Li-ion batteries is very nonlinear with both calendar and cycling losses occurring much more rapidly at temperatures above 80F than below. If you also consider that low-mileage, well-babied LEAFs in Phoenix lost their first capacity bar not too long after cars that were driven a lot and charged to 100% frequently, you have to conclude that calendar losses dominate over cycling losses in hot climates where vehicles that have lost bars to date live. I simply do not expect much calendar loss at temperatures below 80F and I expect reduced cycling losses as well.

As such, I expect to see roughly what we are seeing: Nearly all lost bars should occur in hot weather and very few lost bars should occur in cold weather. That said, I will agree that this effect may be somewhat exaggerated by the LEAF BMS which seems to overestimate the effects of even slightly cold weather on vehicle efficiency. That would tend to make the car think it has more battery capacity in cold weather than it actually does since the car drives farther than it thinks it should at the efficiencies it reports. Since I think bar losses would be quite low in winter anyway, it doesn't take too much error in the BMS to virtually eliminate them.

I will make the prediction that we will not see just a trickle of lost bars being reported starting in late April or early May, but rather I expect to see double, if not triple or more the number of reports as we saw last year. These reports will likely be coming from not just Arizona, but also from CA, TX, FL, OK and perhaps other hot-weather states. I also wonder if we may get the first report of a bar loss in WA from Steve this year.

 

[ewodraska]

I wonder if Nissan has ever accepted buyback on any 1-bar lost LEAF yet or not? Maybe you need to lose at least 2 bars?

I would wait until you lose your second bar and contact Nissan again with a new request.

If you already lost 2 bars and still got denied, I'd try to contact the local news and ask them to help ask Nissan why you got denied but others got approved. I remember one of the news stations in AZ has a program where they step in and contact the vendor on your behalf to help settle your dispute with the vendor. Ask them if they may want to do another news piece about how Nissan's buyback process is inconsistent and unfair.[/quote]


Nissan did a lease conversion on a Tucson Leaf with one bar missing. I believe DesertDenizen had less than 7k miles on the vehicle when they lost their first bar at 14 months. I lost my first bar at 13k miles and 16 months. Both of us went through two summers in Tucson and lost our bars within ONE day of each other even though I had twice the mileage of their car.

I will most likely lose my second bar in May, which will put me over the two year mark and ineligible for a buyback.
If my appeal to the BBB doesn't go through, then I will either have to live with a defective car, or hire a lawyer and go through the lemon law process.

 

[DaveinOlyWA]

As I mentioned before, if this were occurring, where there is NO winter (equatorial!) LEAFs would lose bars at a constant rate year-round, and, IMO, we would probably have seen (and maybe we soon will see, proving you correct) a higher distribution of Winter bar loss of occurrences in loss in like Hawaii, where the is very little "Winter".

There is also at least one report, IIRC, of a high mileage PNW LEAF that has capacity loss greater than 15%, but that still has 12 bars. Future reports from cooler regions might tend to contradict Nissan's many statements that the capacity bar "gauge error" is "pessimistic" in all circumstances.

IMO, it's a lot easier to see what bar loss is NOT- an accurate report of battery capacity, than to try to determine what exactly is causing what we seem to be seeing, the capacity bars disappearing prematurely in hotter climates, and during the Warmer months only.

WetEV wrote:
The following numbers are made up to explain my point. Suppose the hot weather loss is over reported by 5%, and the winter capacity is exact. In other words, if the car would have lost a bar at 15% if gauge was accurate, it would instead lose a bar at 10% in hot weather. In the cold weather, the bar loss is correctly and accurately at 15%. So if the car almost lose a bar in the summer at 9.9% loss, the car would need to drop to 15% loss to lose a bar in winter. So then with this pattern, there would many bars lost in summer, and none lost in winter.
All we can say from the lack of winter bar losses is that the summer reading is more pessimistic than the winter reading. Which of the two is more accurate isn't clear.

what is your verification of that? oh wait! you dont have any because no one does. last verification check by GID meter had his loss at about 11-12%. that was a while ago and he has no doubt lost more since then but it very well could still be under 15% albeit not by much I am guessing.

 

[RickS]

I'm still down only 1 bar, and will cross 20K miles in the next day or two. Cinco de Mayo will be two years for me. I suspect I will loose the second bar soon also.

I posted a link to my site on their facebook page a few days ago mentioning the capacity loss. Some how they have not removed it yet.

 

[LEAFfan]

Rick, do you have a meter (BCM or Gid)? If not, just let me know if you want a BC check.

 

[Volusiano]

I will most likely lose my second bar in May, which will put me over the two year mark and ineligible for a buyback.

I didn't realize that there's a 2-year mark deadline in Nissan's buyback process. Did Nissan actually tell you about the 2-year mark, or is it something you're guessing? Their criteria for buyback approval is so secretive anyway that nobody really knows what they are.

If you're just thinking 2 year mark as pertaining to the AZ lemon law deadline, I think that as long as you have reported the issue to Nissan within the first 2 years, then you will have satisfied that deadline even if the negotiation drags on beyond the first 2 years. But then again, I'm no lawyer. But that's how I would interpret the 2 year deadline in the AZ lemon law.

 

[davekern]

Well, lost my second capacity bar yesterday. Just 6 1/2 months after the first. So, here we are 21 months out with 27k miles in moderate weather San Diego. I was going to update the Wiki database but someone did it for me last time and not sure how to do it...

 

[TonyWilliams]

Well, lost my second capacity bar yesterday. Just 6 1/2 months after the first. So, here we are 21 months out with 27k miles in moderate weather San Diego. I was going to update the Wiki database but someone did it for me last time and not sure how to do it...

Wow!

Any chance you are inland significantly (Lakeside / El Cajon) ?

 

[davekern]

I am inland in Poway. Still, it's not Arizona hot...

 

[smkettner]

Well, lost my second capacity bar yesterday. Just 6 1/2 months after the first. So, here we are 21 months out with 27k miles in moderate weather San Diego. I was going to update the Wiki database but someone did it for me last time and not sure how to do it...

I must be getting close. Same age and 29k miles. I did conservatively drive 72 miles on one charge recently....

 

[davekern]

I have a hard time going 60 miles now. That going the speed limit or below (can be scary) and no ac or heat. Not very useful anymore. I now need an exit.

 

[DaveinOlyWA]

Well, lost my second capacity bar yesterday. Just 6 1/2 months after the first. So, here we are 21 months out with 27k miles in moderate weather San Diego. I was going to update the Wiki database but someone did it for me last time and not sure how to do it...

sorry to hear about your LEAF! you are the first (that I know of) who has lost that much range in what is fairly moderate climate. How often do you see 90º? is it not pretty rare there?

 

[DaveinOlyWA]

I have a hard time going 60 miles now. That going the speed limit or below (can be scary) and no ac or heat. Not very useful anymore. I now need an exit.

i drive slower in Winter because I need the range but it doesnt bother me anymore (never really bothered me very much...) besides, I always still seem to have to change lanes to pass people even at 55 mph so its all relative.