Phoenix Range Test Results, September 15, 2012

evnow said:

Are you implying that the image somehow proves instrumentation problem ? Yes, there is the well known GOM instrumentation problem ...

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Yes, for example. What I'm saying is that the instrumentation is out of whack below the low battery warning, which I observed on Saturday as well. Not only does the GOM deliver an inaccurate range prediction, the range achieved below low battery is not consistent with new Leafs. Randy's car delivers about 30% of its range after the low battery warning, which makes it difficult to operate. What if the vehicle deteriorates further, and up to 50% of his range will be below the low battery warning? I would be curious to know how many consumers want to drive with flashing digits and dashes.

surfingslovak said:

What I'm saying is that the instrumentation is out of what below the low battery warning, which I observed on Saturday.

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I don't quite get what you are saying here ...

evnow said:

surfingslovak said:

What I'm saying is that the instrumentation is out of what below the low battery warning, which I observed on Saturday.

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I don't quite get what you are saying here ...

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Did you see my post in the other thread?

Stoaty said:

edatoakrun said:

Below, in my opinion, is an accurate short summary of the test results, and significant conclusions, based on the partial release of test data:

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Ed, we already know your opinion. Please give it a rest.

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I think Ed only wants more data to find the bad procedures in that, too.

But, I will say any Nissan press release will be closer to Ed's BS than anything else. Again guys, not a science experiment on open highways; a demonstration. Yes, we already know that an 84 mile car is missing from the data... I knew that long before Ed had pontificated it several times here.

So, if Ed is paying, I'll be happy to round up that loose end. If Nissan is throwing out a statement similar to Ed's, the additional data that Nissan may find missing will get provided. Believe me.

So far, the only data they need is how far the cars went in similar conditions. The worst one went 25% less than the best one. Gosh, you don't need OCV, or Gids, etc for that.

Is it possible that the instruments are shutting the cars down to protect the battery, even though they still have more capacity?

Sorry I don't follow the board as much as most here, this may be a silly question but I always believe the silliest questions are the ones that are not asked.

The Gid meter seems to be the most accurate measure that has been found, but it still relies on data the vehicle gives it. There is a pad of energy at the low and top ends so if the software that is measuring that pad is faulty, the vehicle says turn off or stop charging to protect the battery, or am I missing something here?

To put the best light on this possible (I am an EV enthusiast and want the Leaf to succeed, I admit it,) - If the above premise is true, would those with reduced range be giving the battery longer life? Clearly that is not what the car is saying with the vanishing capacity bars, but this test kind of shows those don't mean a whole lot.

I would be interested in your opinions.

I am thinking the heat of AZ is telling the vehicle to only allow a lower percentage charge, and a larger buffer at the bottom. It would be nice if this were true, but I am an optimist. Perhaps taking one of those cars to a colder environment (Or wait till winter arrives) would help answer this.

I have noticed in the heat of this summer my car does not seem to charge to as high a 10 bar 80% as it once did - can we be certain this is battery degradation or just software protection for the battery?

Kudos to all of you that participated and made this test happen, especially you Tony.

At Tony Williams;

I may not understand the whole issue here but, I appreciate your attempt to do the testing, come to your conclusion and post the information with everyone here. It is a shame that certain people have taken it upon themselves to poke holes at your testing when none of them have taken the time like you to coordinate and do the testing.

I am not having this issue in Cedar Park, Texas that I can tell on my 8 month old 2011 Leaf and am glad I am leasing it as it will be Nissan's problem in 30 months. By then battery tech will be better and range will be longer. If Nissan or Infiniti don't have a longer range EV that I like, then this one will be returned and I will get whatever next EV that I like and can afford.

Should my battery start having these documented issues from your testing, I hope Nissan will address before my lease is up.

Is there a way to find out the total number of Leafs owned/leased in this forum vs the total sold in the U.S. to determine what percentage of U.S. sales we are?

Thanks again,

Ian B

Caracalover said:

Is it possible that the instruments are shutting the cars down to protect the battery, even though they still have more capacity?.... There is a pad of energy at the low and top ends so if the software that is measuring that pad is faulty, the vehicle says turn off or stop charging to protect the battery, or am I missing something here?...
Kudos to all of you that participated and made this test happen, especially you Tony.

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Thanks!!! I genuinely appreciate the thought.


Ding! Ding! Ding!

Yes, that is probably one of several problems with the car. The hall effect coulomb counter is probably faulty (or affected by heat, or programmed wrong, etc). We had crazy insane variable LBW, VLB distance variations, and those warnings are indexed directly to the coulomb counting (and adjusted at OCV, of which we would not have had, since we never shut the cars down until turtle).

The battery obviously has less stored energy in some cars than others, but the turtle voltages had a SIXTY volt spread. I'll suggest that batteries at 350 volts could have gone much farther, maybe as far as my car went with 290 volts remaining. This reeks of a BMS problem; hardware of software, or both.

But, there's little doubt in my mind the batteries themselves are also degrading, and that is accelerated in heat, as was predicted by so many before this car was built.

So, I see three probable problems, and perhaps many more.

MrIanB said:

At Tony Williams;

I may not understand the whole issue here but, I appreciate your attempt to do the testing, come to your conclusion and post the information with everyone here....

Is there a way to find out the total number of Leafs owned/leased in this forum vs the total sold in the U.S. to determine what percentage of U.S. sales we are?

Thanks again,

Ian B

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Ian, I thank you for the sentiment. I don't mind a few pokes, but some are broken records. Ed has previously declared that both my range chart, and now this work is a complete mess. He's consistent, I'll give him that.

I don't have any idea how to get that info, but maybe just try calling Nissan? They might have that.

Tony

Ingineer said:

...
It's looking like there is some degradation in these hot-climate packs, but it appears that the BMS (LBC) is not dealing with it properly, and not only indicating incorrect loss figures, but also possibly not allowing for full use (charging) of the packs real capacity.

Keep in mind, Nissan did a lot of testing, but the bulk of it is accelerated life tests, which attempt to simulate a much longer real-world use scenario. Unfortunately sometimes there is no substitute for real-world life testing, and it sounds like there are some unexpected results that the BMS software is not equipped to deal with....

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Phil, I imagine you've had to look into this in some detail while readying LeafScan. Do you have any insight to what actions a driver might take to "help" the BMS along? Specifically I am wondering about frequency of 100% charges to present the pack with rebalancing opportunities? An occasional quick-charge?

Thanks for the post. Makes a lot of sense and I've probably been too dismissive of the Nissan's software claims. Easy to lose sight of the fact that a lot of data gathering and assumptions have been based on GID's which are after all a dynamically-generated abstraction and not a unit of measurement.

TonyWilliams said:

But, there's little doubt in my mind the batteries themselves are also degrading, and that is accelerated in heat, as was predicted by so many before this car was built.

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Little doubt, or no doubt? Obviously all batteries will degrade from the moment they are made, to what extent we still have no clue, or do we?

Don't let the predictions make the science.

I am sure my batteries are degrading a little bit every day - it would shock and awe me if they were not. Is there a way to quantify how much at this point, or is it still an unknown?

My Leaf has almost 22000 miles on it, and over the last few months it has been exposed to some pretty high heat, as it was last summer. No lost capacity bar, but it does seem to hit LBW a little easier than it did before. How much of this is due to the latest software upgrade and how much is due to normal degradation? I don't really expect any one to be able to answer that, but if anyone can it would be useful information.

I liken this to the learning that must have gone on when the ICE first began. How long will an engine run with no oil, or after the coolant is taken out of the radiator? Pretty cool to be a part of it, even if it is just from driving #567.

Again, Kudos to you for going well beyond what I am willing to test.

surfingslovak said:

evnow said:

surfingslovak said:

What I'm saying is that the instrumentation is out of what below the low battery warning, which I observed on Saturday.

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I don't quite get what you are saying here ...

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Did you see my post in the other thread?

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Expecting others to follow posts in the other thread is tenuous. I'm with evnow - showing a pic with GOM = 47 mi and then saying that it went 20 miles farther than it claimed it might doesn't show anything except what we already know - the GOM is horribly inaccurate on a full charge. Now if you showed a pic of the dash right after LBW where the GOM will typically read around 9 mi and then said I drove 20 miles before turtle - that would better show that the gauges are wonky. But then again - we all know that the GOM tends to be pessimistic below LBW. Anyway - beating a dead-horse here - what's really interesting are your observations on the GID/GOM once you got to LBW.

TonyWilliams said:

Yes, we already know that an 84 mile car is missing from the data...

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I'm not quite sure why there's fixation on a "84 miles" when the gauges in the car can't be relied upon. To assume that a new car should have gotten 84 miles on the range test would mean that you'd have to assume that the cars accurately reported 4.0 mi/kWh (which you've said we can't) and that 84 miles is typical for a new car (which Nissan has not claimed - they have only claimed a range of 76-84 miles is typical at an efficiency of 4.0 mi/kWh).

TonyWilliams said:

So far, the only data they need is how far the cars went in similar conditions. The worst one went 25% less than the best one. Gosh, you don't need OCV, or Gids, etc for that.

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No argument there. The test has shown that perfectly and without any doubt.

TonyWilliams said:

turtle voltages had a SIXTY volt spread. I'll suggest that batteries at 350 volts could have gone much farther, maybe as far as my car went with 290 volts remaining. This reeks of a BMS problem; hardware of software, or both.

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There's only two things that might cause one car to turtle at 350V and another to turtle at 290V.

1. A software problem. No further explanation needed here.
2. At least one cell-pair with significantly lower capacity than the rest - one cell-pair hit the low-voltage limit and the BMS shut the party down. Should be easy to check with a Consult by taking this car down near turtle.

I doubt it's a balancing problem - the OCV of the cars after being charged to 100% looked to be grouped together pretty well and appeared to be within normal variation of 100% charge voltage. If this car showed a lower than average OCV after being fully charged, then that would indicate that the BMS is having a hard time keeping the pack balanced. Weak cells will tend to drift faster than others due to their higher internal resistance.

Now, TickTock has gathered and posted a lot of great data regarding GID counts and battery pack voltage such as this example. One can see from this plot that with a pack at 350V, there's really not much left in the pack. (note that perhaps TickTock's car may not be the best source of data here! I think surfingslovak or garygid may have similar data - would be nice to compare) Maybe 20 gids or 1.6 kWh. This is typically VLBW territory on a healthy battery pack. So no more than 6 miles at 4 mi/kWh. Unless this was one of the better 10-bar cars, I'd guess that it'd highly unlikely that it would have gone as far as your car. Of course - if we knew how far your car went from 350V to 290V and turtle, we could make a much more accurate estimate as to how far the might have driven with the issue corrected.

Anyway - like I've said before - this test has been a wonderful success - it's definitely achieved it's goals. And the data shared so far certainly is interesting and gives very good clues as to where the real problems lie.

evnow said:

surfingslovak said:

Have a look at Randy's GOM readout from yesterday. I drove his car 67.3 miles during the range test Saturday morning. The low battery warning came up after about 49 miles.

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Are you implying that the image somehow proves instrumentation problem ? Yes, there is the well known GOM instrumentation problem.

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I agree with Evnow that you can't call out the GOM as bad instrumentation. The dealership can easily dismiss it as just an estimating instrument based on previous driving conditions such as high speed with AC or heater and stuff and is never accurate. They will never admit that there's anything wrong with it, and therefore they will never agree to fix anything on the GOM.

So, aside from the GOM meter, what other instrument inaccuracy can you find that can easily be pointed out to the dealership without elaborate and lengthly testing, so that they have no choice but to admit that something is wrong and agree to try to fix it?

I'm asking this not so much as a challenge to anyone, but I genuinely want to find out if a loophole truly exists from the instrumentation accuracy angle that can be turned into a Lemon Law leverage like Tony pointed out. If so, I will for sure take advantage of it so I can return my car to Nissan.

surfingslovak said:

What I'm saying is that the instrumentation is out of whack below the low battery warning, which I observed on Saturday as well.

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But in the case of Randy's car, it is dead nuts on if it's showing you the estimated range to the point where Nissan expects that you'll be plugging it in (if not sooner). The owners manual definitely gives me the impression that hitting LBW is like when your gas gauge lights up. It's saying, "hey idiot, it's time to stop and fill up now." It's not going to tell you how many miles you have left until you are running on gas fumes because the car is already saying "do it now." But we all know there is a bit of a buffer there and the needle really has to be buried before you completely run out. So... in the case of our car, the GOM now shows a number in the high 60s every morning after a 100% charge, and that's realistically what we can get without dragging it into LBW and VLBW, provided we're rather conservative with speed and air conditioner use. Nissan says this is where you look for a charger. So I don't care too much if there are 2,784 driving miles available below LBW. That is where Nissan is suggesting that the car be recharged. If I drag the pack down below this point (on a regular basis), I run the risk of having Nissan point the finger at me and blame me for capacity loss.

Duplicate

drees said:

TonyWilliams said:

Yes, we already know that an 84 mile car is missing from the data...

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I'm not quite sure why there's fixation on a "84 miles" when the gauges in the car can't be relied upon. To assume that a new car should have gotten 84 miles on the range test would mean that you'd have to assume that the cars accurately reported 4.0 mi/kWh (which you've said we can't) and that 84 miles is typical for a new car (which Nissan has not claimed - they have only claimed a range of 76-84 miles is typical at an efficiency of 4.0 mi/kWh).

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84 miles for a new car is probable. "Black782" would have banged that out 2-3 months ago, and did PLENTY of times on my BC2BC trip. I used Nissan's data of 84 miles because I didn't have a car in the test that did it. Like I've said several times now, if Nissan wants challenge that, I will be more than happy to find one or more new cars right here in SoCal to bang out 84 miles.

My car did show exactly 4.0 miles/kWh on the outbound leg, and 3.8 inbound (I reset at the halfway point, like I've outlined previously to determine wind effects). If you look at the wind chart for 0251Z, the wind was reported from the east at 6 knots. The inbound leg was east (except the last 6 miles that is north/south.

So, again (I've said this several times), my car's data hit the predictions very well. My average economy was 3.9, and this matched all the expectations before I ever turned the car on that morning. The only unexpected surprise was not having 100% available to start. But it did in the very recent past.

So, to Nissan 76-84 mile thing. Sure, they can argue all kinds of BS, but I went 76, so I guess that meets the normal range. But, sure, and also matched my economy by 0.1 miles/kWh. But, if you don't think a car will go 84 miles, then you are not believing Nissan's own data.

A new LEAF will do it, and Nissan publishes that it can do 84 at that 4 mile economy, which is the economy that my car did (within 0.1.. the center Nav screen would shown 4.0).

Interesting though when faced with a battery that is 70%, 80% or 90% capacity knowing that at best, LBW occurs with about 4 kWh remaining in the pack and for the sake of the argument, range when new is 80 miles.

We all know that the average user doesn't like to go below LBW - which means leaving 4 kWh (out of 22.5 kWh assuming 281GID and 1GID=80Wh) on the table. We'll call 100% - LBW "usable".

100% capacity = 22.5 kWh - 4 kWh = 18.5 kWh, 66 mi before LBW.
90% capacity = 20.3 kWh - 4 kWh = 16.3 kWh, 58 mi before LBW, 12% reduction in usable range.
85% capacity = 19.1 kWh - 4 kWh = 15.1 kWh, 54 mi before LBW, 19% reduction in usable range.
80% capacity = 18.0 kWh - 4 kWh = 14.0 kWh, 50 mi before LBW, 25% reduction in usable range.
70% capacity = 15.8 kWh - 4 kWh = 11.8 kWh, 42 mi before LBW, 36% reduction in usable range.

So for most people (who generally try to avoid LBW and below), the higher the capacity loss - the worse the reduction in range feels 20% worse because of the fixed LBW setting. This could be even worse since it appears that the BMS appears to bury even more of the battery below LBW once you've lost a bar or more...

Psychologically - a 15% loss in capacity sure feels huge - going from 66 mi to LBW to 54 mi to LBW sure feels a lot worse than only being able to go 68 miles / before turtle compared to 80 miles before.

This feels even worse if one tries to charge to 80% mostly and they've lost a bar. Then they go from 52 mi before LBW to 42 mi before LBW - a 20% reduction in usable range.

opossum said:

So... in the case of our car, the GOM now shows a number in the high 60s every morning after a 100% charge, and that's realistically what we can get without dragging it into LBW and VLBW, provided we're rather conservative with speed and air conditioner use. Nissan says this is where you look for a charger. So I don't care too much if there are 2,784 driving miles available below LBW. That is where Nissan is suggesting that the car be recharged. If I drag the pack down below this point (on a regular basis), I run the risk of having Nissan point the finger at me and blame me for capacity loss.

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That's a good point, and the GOM apparently behaves the same way in Randy's Leaf as well. He realistically has about 50 miles before hitting the low battery warning, and the GOM was showing 47 yesterday.

But back to Volusiano's question. What other instrument or control is out of whack or behaving inconsistently? I could think of the obvious one: battery capacity bars. If I recall correctly, they were not showing the correct remaining capacity in a number of cars. Several of us have the 2011 shop manual and could make the relevant section available.

Then there is the less obvious one: energy economy. It should have been about 4 m/kWh for all of the cars, but some of them were not even close. Randy's car ended the test at 4.4 m/kWh. This defect might be hard to prove without proper instrumentation or a dyno, but it would also be nearly impossible to fix.

Is there anything else we could be missing?

drees said:

TonyWilliams said:

turtle voltages had a SIXTY volt spread. I'll suggest that batteries at 350 volts could have gone much farther, maybe as far as my car went with 290 volts remaining. This reeks of a BMS problem; hardware of software, or both.

Click to expand...

There's only two things that might cause one car to turtle at 350V and another to turtle at 290V.

1. A software problem. No further explanation needed here.
2. At least one cell-pair with significantly lower capacity than the rest - one cell-pair hit the low-voltage limit and the BMS shut the party down. Should be easy to check with a Consult by taking this car down near turtle.

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Agreed, except I think a software problem is a very long shot here. I would expect software problems to arise in more than a couple cars and in more than just one climate.

The BMS in the LEAF terminates both charging and discharging based on voltages at the cell and the pack level. Phil has told us that his LEAF's voltmeters appear to be accurate to within about 0.1% and that the low-voltage meters cross-check with the high-voltage meters and throw codes if there is a discrepancy. So, no, I do not think we are losing any range due to instrumentation issues.

The sixty-volt difference in discharge voltage is *precisely* what I would expect to see between a new pack and a severely degraded pack. The cells in the new pack should all have similar capacities, so none should go below the knee prematurely. But in a pack without a TMS driven in a very hot climate some cells will live in an even HOTTER environment than others. Those cells will deteriorate faster and will therefore have higher internal electrical resistance, possible greatly higher. As a result those cells will get even hotter and will quickly go downhill.

This condition is exactly what Nissan's CELL VOLTAGE LOSS INSPECTION test is designed to identify. If Scott's car is the one that terminated at 350V, then I find it irresponsible that Nissan has not reported the amount of variation found in the cells in his pack.

Again, I will say that I would find a histogram of cell capacities from a degraded LEAF to be quite informative right about now. I don't think we can expect to get that from Nissan. Anyone want to purchase a battery and give the old one to Phil to document?

Below, in my opinion, is an accurate short summary of the test results, and significant conclusions, based on the partial release of test data:

After selecting LEAFs nationwide, whose drivers believed them to have some of the largest range losses, a recent range test in Phoenix showed less than the range loss as had been expected, by relying on what the test showed were inaccurate capacity bars displays, and "gid" counts.

One outlier on the low side got only 59.3 miles. The unknown conditions experienced by this LEAF during over 29,000 miles of use, make it impossible to determine if any factor or factors of use contributed to this car's relative under-performance.

While the other eleven of the twelve did all have close to the highway range (and many, even more) that Nissan had estimated for new LEAFs in its promotional materials, many, but not all, seemed to show a significant reduction from the higher "new" LEAF range, as estimated by another source, Nissan Technical Bulletin NTB11-076a.

There was large variability between the LEAFs individual ranges, of between 66.1 and 79.6 miles. Inadequate test protocols could only seem to explain a small part of the large range disparities, between all twelve cars.

We can now conclude, in all likelihood, that many or all LEAFs have a a significant flaw or flaws in their energy use reports, that make it difficult to determine with great precision what capacity or range loss has been experienced by any LEAF, either from new, or from an assumed standard range.

Alternate means of testing of the battery capacity, such as by measuring the charge accepted, might allow more accurate battery capacity results, from which standardized ranges at m/kWh use levels, could be calculated.

However, all data indicating accuracy or inaccuracy of all m/kWh reports from the test LEAFs, has so far been withheld, by the promoter of the range test.

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Stoaty
Ed, we already know your opinion. Please give it a rest.

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No, I don't think I will.

I wrote that summary above because of the deficiencies of Tony’s own effort. But I would appreciate your future comments, and those of any others, related to the accuracy of the summary that I posted above. My intent was to post a short and accurate summary of the most significant findings from the data reported from the range test. I’m sure it can be improved. I may have left out more important conclusions, made errors, in presentation or emphasis, and I could even have facts wrong. If so, I hope these errors will be pointed out, to me, so that they can be corrected.

Any substantive comment, of course requires you to review the data and much longer summary written by Tony, and posted on page one of this thread, and review that for accuracy. I think you will find it is significantly flawed, both in data presentation, and in the conclusions made. I wrote the alternate summary because of the significant deficiencies of Tony’s own effort, and my belief that all present and future LEAF drivers deserve an accurate presentation of the test results. Those who participated in the test, giving much effort , and some incurring significant expense and damage to their Leafs, even more so.

Much of the most important data (IMO) apparently was not collected during the test. Other data, which Tony has previously characterized as “bad”, is still being withheld by Tony, but is trickling out in the comments of others, or selectively released by Tony, as in the m/kWh results from one LEAF in his own comment, below.

I hope other test participants will also continue to post more of the “bad’ data, as well as continue to correct the factual data errors in Tony’s comments.

There is actually much more to write about many other interesting aspects of the test results, as some of the comments of others have shown.

I’m sure I will have a few more points to make myself, if no one else does first, (hopefully) after more complete data from the test becomes available.

TonyWilliams said:

drees said:

TonyWilliams said:

Yes, we already know that an 84 mile car is missing from the data...

Click to expand...

I'm not quite sure why there's fixation on a "84 miles" when the gauges in the car can't be relied upon. To assume that a new car should have gotten 84 miles on the range test would mean that you'd have to assume that the cars accurately reported 4.0 mi/kWh (which you've said we can't) and that 84 miles is typical for a new car (which Nissan has not claimed - they have only claimed a range of 76-84 miles is typical at an efficiency of 4.0 mi/kWh).

Click to expand...

84 miles for a new car is probable. "Black782" would have banged that out 2-3 months ago, and did PLENTY of times on my BC2BC trip. I used Nissan's data of 84 miles because I didn't have a car in the test that did it. Like I've said several times now, if Nissan wants challenge that, I will be more than happy to find one or more new cars right here in SoCal to bang out 84 miles.

My car did show exactly 4.0 miles/kWh on the outbound leg, and 3.8 inbound (I reset at the halfway point, like I've outlined previously to determine wind effects). If you look at the wind chart for 0251Z, the wind was reported from the east at 6 knots. The inbound leg was east (except the last 6 miles that is north/south.

So, again (I've said this several times), my car's data hit the predictions very well. My average economy was 3.9, and this matched all the expectations before I ever turned the car on that morning. The only unexpected surprise was not having 100% available to start. But it did in the very recent past.

So, to Nissan 76-84 mile thing. Sure, they can argue all kinds of BS, but I went 76, so I guess that meets the normal range. But, sure, and also matched my economy by 0.1 miles/kWh. But, if you don't think a car will go 84 miles, then you are not believing Nissan's own data.

A new LEAF will do it, and Nissan publishes that it can do 84 at that 4 mile economy, which is the economy that my car did (within 0.1.. the center Nav screen would shown 4.0).

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drees said:

Interesting though when faced with a battery that is 70%, 80% or 90% capacity knowing that at best, LBW occurs with about 4 kWh remaining in the pack and for the sake of the argument, range when new is 80 miles.

We all know that the average user doesn't like to go below LBW - which means leaving 4 kWh (out of 22.5 kWh assuming 281GID and 1GID=80Wh) on the table. We'll call 100% - LBW "usable".

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OK correct me if I am wrong here but I seem to remember reading somewhere else that 21 kWh was what was usable not 22.5