Phoenix Range Test Results, September 15, 2012

I kept looking at the other thread for three days waiting for results, too stupid to check this forum.

Great job Tony AND everybody else who put time in. I know a few people put in serious effort in addition to Tony.

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Yanquetino said:

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Click to expand...

VERY thoughtful review. Thank you for posting this.

Yanquetino said:

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Click to expand...

Yes, that is an interesting perspective. However it should be noted that there Leafs in colder climates, who have NOT experienced similar degradation, despite having similar mileage or more. It all depends what you consider the baseline performance, but I guess Nissan spelled that out in their manual.

Also note that the capacity bars (like many other things in the LEAFs displays) are apparently NOT linear, so the first bar is NOT 8.3% but 15%. I think this non-linearity (also for the temperature) is a BIG mistake on Nissans side, since people generally cannot cope with non-linearity well (unless its asymptotic).

Yanquetino said:

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Click to expand...

I think you generally raise a good point about the 76 vs. 84 miles.
However, you have some errors in your review...

Unless I am mistaken in my arithmetic, another error is the percentage they assign to each capacity bar in the gauge. There are 12 such bars, and if we divide 100% by that number, the result is 8.34% per bar. Yet they informed Green Car Reports that “11 capacity bars showing instead of the full 12 capacity bars” indicates “approximately 15 percent loss in battery capacity” —nearly twice the actual amount.

Click to expand...

An early version of Nissan's technical manual states that the capacity gauge was not linear. The first bar represents 15%. This invalidates part of your analysis towards the end.

For example, as I have indicated in the last column, it would be informative to know the number of quick charges and/or 100% charges they have undergone, since Nissan explicitly warns owners that these factors can have a detrimental effect upon the battery pack’s longevity over time.

Click to expand...

This is a misleading statement. Nissan does state this in a general sort of way in the owners manual but they have gone onto clarify in various interviews and such that they are talking about multiple QCs a day, or leaving the battery charged at a 100% for long periods of time. They have given the impression that their batteries are very robust and only serious abuse beyond that of the average owner would cause premature capacity loss. Furthermore a broader look at all the Leafs showing capacity bars missing from this forum indicates that charging habits have weak correlation to capacity loss.

Yanquetino said:

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Click to expand...

I will read this shortly.

I think there is basically no value at all in considering these cars against the mythical 84 mile range, because they were not on a course used to set that baseline. The most important data is that there is a big variance in cars that are all quite young. Even taking out the 60 mile car-- because who knows its history--we see really substantial differences in ranges of the other cars.

It is difficult to make strong conclusions with 12 cars and none older than two years. Thames tat in three years from now would be even more interesting

EDIT : read hat review. Some compelling points.

so capacity loss by this method is:


That puts car 494 clearly over the 20% range which is what Nissan says we should have in 5 years, and car 272 is entering the grey area, but all other cars are still within Nissan's specification.

I agree that this document puts the 76 mile range as the standard to hold up against, and this does change the view of the results. It does not change the fact that the cars are not going as far as they did, and the owners are still probably upset, but I'm glad we are seeing some good analysis of this test.

The other shocking thing from reading the TSB in detail was just how much capacity is now on the last bar and below. I think this change has been the biggest problem. The earlier software did not seem (I have no data to prove this, just my gut feel) to have so much "reserve" on and below the last bar. At an economy of 4.0 you have 16 miles of range at the last bar. Given that we are supposed to have 76 miles range total that means the last bar represents 21 percent of the usable capacity! Think about that. 21 percent of the usable range is now on the last bar. Most of us start looking for a place to plug in on the last bar. I wish I knew what it was on the earlier software.

Yanquetino said:

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle

Click to expand...

Mark, while it's interesting to read your study, I would be careful with long-term predictions, and even more careful about passing judgement on affected owners. Since this problem seems to interest you, may I suggest that you got in touch with some of them and found a way to examine their vehicle? I suspect that it will be a revelation.

That said, several of us tried to make predictions about the trajectory and the velocity of changes this phenomenon represents. I don't think that anyone had any conclusive answers at this point. My recommendation is to follow the developments and check in a few months to see how well your model is working out.

And more to the point, I don't agree with the 76 miles range estimate at 4 m/kWh for a new vehicle. That implies 19 kWh usable. Happy to be proven wrong on this, but this does not jive with what new Leaf owners report.

Unlike GM did for the Volt, Nissan never disclosed the usable battery capacity, which leaves us all guessing. Phil delivered some very interesting figures, but if memory serves, they all represented stored energy. As far as I can recall, we have not measured and integrated the energy outflow from the battery, and have little to go by, except for the numbers supplied by dash instruments.

Interestingly, NTB11-076a itself seems to suggest 21 kWh usable if you crunch their numbers, which was my main takeaway when the bulletin was published.

Yanquetino said:

EatsShootsandLeafs said:

These results confirm what most of us suspected: A real loss of range, prematurely. The only saving grace of these particular cars is if the loss of capacity now stops and I cannot imagine any of us expect that. Clearly these batteries have lost capacity much faster than Nissan indicated they would, or that they should have, thus making these particular cars not usable long term.

Click to expand...

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle



* Extrapolated from Nissan Technical Bulletin NTB11-076a: Nissan LEAF Range Estimates at 4 Miles-per-kWh

Click to expand...

very nice story but...

you state you did not see any car losing capacity at 3X the rate of others but you are only looking at AZ cars. look at mine. 21,800 miles, estimated degradation of 2%.

you also dispute the value of the capacity bars then go on to show how the LEAFs are going farther than they should based on the capacity bars missing but you are assigning a value of 8% to each when the first one is 15%. so ya, your chart will appear that the LEAFs are going farther than expected because you have not assigned the correct value to the missing bars.

other than that; i agree with you. this has become a witch hunt and its hard to place blame on owners especially when some are to the point where they can no longer make the commutes they need to make. Nissan obviously has an action plan they are working on since i would find it very difficult to believe they would allow this much ill will to go on when its really not that much money to them but could easily cost millions in trash talking.

the way i see it; Nissan can do the "right thing" (whatever that is) for the AZ owners (at least the worst of them) and if it is right enough, in a year less than a quarter of the world will remember anything about it or let the AZ owners do as the might, sue, etc. knowing that the upgrades coming down the line are so compelling, the LEAF will sell no matter what.

as far as options out there. a lot of people here seem to think there is a bunch. i do not. the rest is either too small, too expensive or does not have quick charge. throw that in the mix and there is not much left standing

klapauzius said:

Also note that the capacity bars (like many other things in the LEAFs displays) are apparently NOT linear, so the first bar is NOT 8.3% but 15%. I think this non-linearity (also for the temperature) is a BIG mistake on Nissans side, since people generally cannot cope with non-linearity well (unless its asymptotic).

Click to expand...

Yes, I have heard that, but please note: if the first bars are not proportional, but represent even higher percentages at the upper levels, then the differences between what the lost bars were predicting and what the actual range was in the test are even greater.

For example, if White626's 11 bars indicated 85% (instead of 92.7%), then the capacity range would predict only 64.6 miles (instead of 69.7 miles), i.e., 8.9 miles lower (instead of 3.8 lower) than the actual 73.5 miles it achieved in the test.

DaveinOlyWA said:

very nice story but...

you state you did not see any car losing capacity at 3X the rate of others but you are only looking at AZ cars. look at mine. 21,800 miles, estimated degradation of 2%.

you also dispute the value of the capacity bars then go on to show how the LEAFs are going farther than they should based on the capacity bars missing but you are assigning a value of 8% to each when the first one is 15%. so ya, your chart will appear that the LEAFs are going farther than expected because you have not assigned the correct value to the missing bars.

Click to expand...

Um... I must be miscalculating...? According to Nissan's projections in the table, 22,000 miles would render a 93% capacity, i.e., a 7% degradation --not 2%. It's too bad your Leaf wasn't in the test; it would be informative to know how far it would actually go with that mileage on the odometer!

Again, please note: increasing the difference in the capacity bar percentage from 8.34% to 15% would make the difference between "capacity" and "achieved range" even larger --not smaller. My proportional percentage is actually favoring the AZ owners' claims more than the 15% would. The latter would lower the capacity prediction; the former raises it. The actual ranges achieved on the test, however, are unaffected by those bar percentages: the Leafs went... as far as they went.

It was the first thing that struck me when I saw the results. Maybe the assumption we have been making that the first bar loss represents a 15% loss in capacity is no longer true and that they really are linear.

On the other hand, to be fair, I would have chosen the middle of the range of mileage-to-empty for 4 miles/kWh, rather than the bottom of the range, as the reference point for any discussion. In other words, 80 miles rather than 76 miles.

Weatherman said:

On the other hand, to be fair, I would have chosen the middle of the range of mileage-to-empty for 4 miles/kWh, rather than the bottom of the range, as the reference point for any discussion. In other words, 80 miles rather than 76 miles.

Click to expand...

Yes, I can see the argument for using the average number. In fact, I had considered doing just that. But ultimately it occurred to me that Nissan could legitimately claim that the ranges were still "normal" if they were close to the lower end of their scale, so... I figured it would be prudent to just settle for the minimal number to which they have to be held officially accountable. And, in fact, the temperatures were slightly higher than in Nissan's bulletin, so the adage that YMMV seems to favor the lower estimate.

Weatherman said:

It was the first thing that struck me when I saw the results. Maybe the assumption we have been making that the first bar loss represents a 15% loss in capacity is no longer true and that they really are linear.
On the other hand, to be fair, I would have chosen the middle of the range of mileage-to-empty for 4 miles/kWh, rather than the bottom of the range, as the reference point for any discussion. In other words, 80 miles rather than 76 miles.

Click to expand...

It's really simple. If you have full battery capacity (new pack), that's around 21 kW h usable. If you show and keep 4.0m/kW h on your dash (like during the test) , you will be able to drive at least 84 miles. Anyone that doesn't realize this is just ignoring the facts.

Yanquetino said:

klapauzius said:

Also note that the capacity bars (like many other things in the LEAFs displays) are apparently NOT linear, so the first bar is NOT 8.3% but 15%. I think this non-linearity (also for the temperature) is a BIG mistake on Nissans side, since people generally cannot cope with non-linearity well (unless its asymptotic).

Click to expand...

Yes, I have heard that, but please note: if the first bars are not proportional, but represent even higher percentages at the upper levels, then the differences between what the lost bars were predicting and what the actual range was in the test are even greater.

For example, if White626's 11 bars indicated 85% (instead of 92.7%), then the capacity range would predict only 64.6 miles (instead of 69.7 miles), i.e., 8.9 miles lower (instead of 3.8 lower) than the actual 73.5 miles it achieved in the test.

Click to expand...

I have finally read your treatise, Mark, it was a bit tough getting through the first portion. It was little too much pontificating for my taste. That said let me sum up what you did:

- take the lowest estimate from NTB11-076a as range expectation for a new Leaf
- assume linear battery capacity degradation dependent on mileage only
- assume linear distribution of battery capacity bars

Let's assume for the moment that the average range in the Phoenix fleet (2011 vehicles only) is down 15%. This is roughly in line with the results Nissan verbally communicated to some owners that had their Leafs examined in Casa Grande. Let's also assume that the usable battery capacity in a new Leaf was in fact 21 kWh, which should be verifiable.

If this was the case, you are virtually erasing 10% from 15% average degradation in the Phoenix fleet by assuming 76 miles of range in a new vehicle. You then proceed to formulate a degradation model based on cycling losses only to fit this artificiality low estimate, and then proclaim that everything is fine. Well done. Did I miss anything?

If you wanted to risk a look at a better effort at analyzing the results, here is a graph from a recent article on thetruthaboutcars.com. This is similar to a plot Stoaty did earlier. Note that the car at 95% and 16,000 miles had in reality a shorter range. Tony misread the results sheet, and it should be at about 90% (Blue534).

LEAFfan said:

It's really simple. If you have full battery capacity (new pack), that's around 21 kW h usable. If you show and keep 4.0m/kW h on your dash (like during the test) , you will be able to drive at least 84 miles. Anyone that doesn't realize this is just ignoring the facts.

Click to expand...

Indeed. The pattern I'm seeing here are a few EV enthusiasts pitting themselves against affected owners thinking that they don't get it. While I applaud what these folks have done for EVs, nothing could be farther from the truth. This is the wrong fight.

LEAFfan said:

It's really simple. If you have full battery capacity (new pack), that's around 21 kW h usable. If you show and keep 4.0m/kW h on your dash (like during the test), you will be able to drive at least 84 miles. Anyone that doesn't realize this is just ignoring the facts.

Click to expand...

Yup! That's the way the abacus adds it up! The caveat is the "around" adverb. I suppose that what Nissan is saying with the 76-to-84 range estimate in its Technical Bulletin NTB11-076a is that a fully charged new Leaf could have around 19-to-21 kWh "usable."

Yanquetino said:

Yup! That's the way the abacus adds it up! The caveat is the "around" adverb. I suppose that what Nissan is saying with the 76-to-84 range estimate in its Technical Bulletin NTB11-076a is that a fully charged new Leaf could have around 19-to-21 kWh "usable."

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Yes, and if they give a range, we must assume the lowest number. But only after accusing others of using the highest number. How about the middle ground then? Would that be agreeable to you?

Yanquetino said:

Sigh.... Given what I have experienced in these forum discussions, I hesitate to state this, but... I draw very different conclusions: AZ Leaf Capacity Kerfuffle

Click to expand...

Nissan's own tests don't agree with your conclusions. One of the affected owners was told that of the 7 cars tested at Casa Grande, the best one had lost 14% of capacity from new. That doesn't sound like they are on track to lose 20% in five years.

Yanquetino said:

Um... I must be miscalculating...? According to Nissan's projections in the table, 22,000 miles would render a 93% capacity, i.e., a 7% degradation --not 2%. It's too bad your Leaf wasn't in the test; it would be informative to know how far it would actually go with that mileage on the odometer!

Click to expand...

Yes, that would have helped a lot to interpret the data beyond the obvious result, i.e. reduced range.
If we knew by how much the range was actually reduced, compared to a new ( or like new) car, that would bring more clarity. Unfortunately this particular test can only be done on the same route, if we want to use the numbers from the AZ test.

I think neither 76 or 84 miles is a reliable number, it would be more important how far a new Leaf on that test route in Phoenix would go. Also, if some of the cars involved in the test could repeat the test, we could learn something about the variability in individual ranges

Stoaty said:

Nissan's own tests don't agree with your conclusions. One of the affected owners was told that of the 7 cars tested at Casa Grande, the best one had lost 14% of capacity from new. That doesn't sound like they are on track to lose 20% in five years.

Click to expand...

Huh. The best one has lost 14%? Was that "best" car in the test? Which one was it? I wonder who the Nissan rep was who told the owner that...? And I wonder how many miles that Leaf had on its odometer...? Sure sounds like Nissan's left hand (whoever said that) doesn't know what its right hand (Palmer) is saying.

If that quote is indeed accurate, I'll be very curious to see what Nissan says, when it says it. "In the near term." "Very soon."