Altered capacity bar thresholds?

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Yup, your analysis is correct. I lost 4th bar at 41.87 Ahr; about 63.2% of original capacity. 43.5K miles, two months after capacity warranty expired. If I had it to do over again, I would not have P3227 done until 4th bar disappeared. There's little doubt that Nissan adjusted the bottoms of the capacity bars downward substantially (and removed any reference to % capacity in the service manual).

With hot weather just beginning, my battery is down to 40.3 Ahr at 45K miles. I'll get four or five more months use out of the car, and then it won't get me home from work anymore. When it starts hitting VLBW every night, it's going to the Salvation Army. LBW is okay; that's happening once or twice a week now.

-Karl
 
This is what we suspected all along, however to be fair we don't really know if the 100% SOH in LeafSpy is the same 100% used in the original revision of the service manual.
 
4 bar loss equals around 70% 8 bars remaining is 66% of bars, which is a lot lower than 70% and 3 bars is 75%. New batteries are about 60 ahr, 4the bar drops around 42 ahr, which is actually 70%. But not every car is dropping the 4th bar at 42. I wonder if the bars are scaled for each battery? That could explain why the bars drop differently for everyone. It would be good if the original capacity can be found and see if the 4 bar dropping is related to the original capacity.
 
Tonyt said:
4 bar loss equals around 70% 8 bars remaining is 66% of bars, which is a lot lower than 70% and 3 bars is 75%. New batteries are about 60 ahr, 4the bar drops around 42 ahr, which is actually 70%. But not every car is dropping the 4th bar at 42.
Your numbers are off. Please read my post that started this thread. Also, a new 24kW battery has 66.25 Ahr, which is the base that LEAFStat and Leaf Spy Pro use to calculate capacity SOH:

Current Ahr ÷ 66.25 Ahr = Current Capacity
 
What we don't know is how accurate the numbers coming out of the car are.

After all, after P3227, the Hx values dropped significantly, as well did the Ahr values after they settled down.

Unless you pull the pack out of the car and measure the remaining capacity compared to what it was when new, it's hard to say for sure how close the AHr values are to the actual values.
 
Yanquetino said:
Tonyt said:
4 bar loss equals around 70% 8 bars remaining is 66% of bars, which is a lot lower than 70% and 3 bars is 75%. New batteries are about 60 ahr, 4the bar drops around 42 ahr, which is actually 70%. But not every car is dropping the 4th bar at 42.
Your numbers are off. Please read my post that started this thread. Also, a new 24kW battery has 66.25 Ahr, which is the base that LEAFStat and Leaf Spy Pro use to calculate capacity SOH:

Current Ahr ÷ 66.25 Ahr = Current Capacity

Thanks. I could not remember the exact beginning number and 60 was in my mind for some reason. With 66 my battery is being relplaced at 64% capacity. I'm not sure when the bar dropped since I purchased the car used.

There is a lot of wiggle room since Nissan states replacement around 70%. And I would not be surprised to hear Nissan say that 66% is about 70%... I would also not be surprised if the update makes the 4th bar drop at a lower ahr.
 
Yanquetino said:
Those who wonder about the capacity bar loss percentages might want to read my post: Strike Three!

I don't agree with your conclusion.

There is a concept called https://en.wikipedia.org/wiki/Hysteresis that I think you need to consider.

The percentage per bar didn't change but the time a bar goes away does lag slightly vs the trigger. That in part is why most use Ahr and Hx instead of SOH to measure when the bar dropped.

I'd also say part of your confusion is you are still using leafstat instead of Leaf spy and the terms, units vary slightly.

At the time of your 3rd bar loss you have

72% SOH
51.85% Hx
47.53 Ahr

my cheat sheet shows

Loss of bar 12 - between 53.75 AHr and 56 AHr
Loss of bar 11 - between 49.75 AHr and 52 AHr
Loss of bar 10 - between 45.75 AHr and 48 AHr
Loss of bar 9 - between 41.75 AHr and 44 AHr

and your Ahr is right in line with that.

Going further the bars per the old manual are

capacity bars
100% to 85% = 12 bars (15%)
85% to 78.75% = 11 bars (6.25%)
78.75% to 72.5% = 10 bars (6.25%)
72.5% to 66.25% = 9 bars (6.25%)
66.25% to 60% = 8 bars (6.25%)
60% to 53.75% = 7 bars (6.25%)
53.75% to 47.5% = 6 bars (6.25%)
47.5% to 41.25% = 5 bars (6.25%)
41.25% to 35% = 4 bars (6.25%)
35% to 28.75% = 3 bars (6.25%)
28.75% to 22.5% = 2 bars (6.25%)
22.5% to 16.25% = 1 bar (6.25%)

and you are in line with that as well.


You seem to think an update changed the behavior but if you go back to the 2012 threads the arizona losers dropped bars before the update in line with the numbers of those of us that got the update and dropped bars after that.
 
dhanson865 said:
The percentage per bar didn't change but the time a bar goes away does lag slightly vs the trigger. That in part is why most use Ahr and Hx instead of SOH to measure when the bar dropped.
I do use Ahr. Indeed, the SOH is simply the result of dividing the Ahr by 66.25 Ahr.
dhanson865 said:
I'd also say part of your confusion is you are still using leafstat instead of Leaf spy and the terms, units vary slightly.
I use both LEAFstat and Leaf Spy Pro. They both gave readouts of 47.53 Ahr when my 3rd bar disappeared.
dhanson865 said:
Going further the bars per the old manual are

capacity bars

78.75% to 72.5% = 10 bars (6.25%)

and you are in line with that as well.
I fail to see how 71.73% is "in line" with that.
dhanson865 said:
You seem to think an update changed the behavior but if you go back to the 2012 threads the arizona losers dropped bars before the update in line with the numbers of those of us that got the update and dropped bars after that.
I didn't know Ahr readouts were ever reported for the AZ owners. Please post them! And sorry: it is not simply that I "think an update changed the behavior." Nissan explicitly stated that the update would change the behavior --supposedly by making the gauges "tighter." Now, if you have Ahr readouts from the AZ owners, and they are even lower than what other owners have since reported in the Nissan Wiki, that would substantiate that the automaker did, in fact, tighten the gauges. Let's see them, please.
 
Looking at your profile you've been on mynissanleaf longer than I have (by a few months). I've read tens of thousands if not hundreds of thousands of posts here. I don't know if you read all the posts I did.

If I were to try and find the AHr from the early losers I'd read http://www.mynissanleaf.com/viewtopic.php?t=8802 for a 3rd or 4th time (I know I've read all 7,000+ posts in that thread and followed the links out of that thread at least twice now.) The last time I did that was to update that wiki of bar loss data you keep linking to that you might notice is in my signature on this board (maybe you are reading from a mobile device and don't see my signature).

I've literally scoured hundreds of threads and made hundreds of entries in that bar loss database you've linked to. But when I do I don't tend to put the Ahr, HX, or SOH in the entry.

You can scour those threads again if you like or you can just disagree with me. I'm just telling you what I remember reading and how I understand the bar loss trigger.

We don't know for a fact if it is based on a single data point with multiple conditions, a moving average of one data type, or a moving average of multiple data types. No data from Nissan has been released (they don't want to tell us) and no reverse engineering from end users has proven the exact trigger logic.

Whatever the trigger logic I don't see any significant variance between the early losers and the late other than temperature and time. I believe the difference between people that lose a bar at higher vs lower AHr are based on the delay in the trigger logic vs the loss curve being steeper or shallower.

You could

A. get the source code from Nissan
B. spend a large amount of time and effort with cells, BMS, test equipment to reverse engineer the drop trigger
C. make your best guess

I'm just telling you from the insane amount of time I've spent researching the issue I came to a different conclusion than you. I've tried to take notes as I went along but I don't think it's worth my time to go through them or the thousands of messages for free. I'm not sure if I'd want to do that data dive again if you paid me.
 
dhanson865 said:
I've read tens of thousands if not hundreds of thousands of posts here. I don't know if you read all the posts I did.
I hear you --and empathize! Yes, I've also read all the posts related to the Phoenix capacity loss kerfuffle since the getgo --so many that it's a wonder we're not cross-eyed at this point. However, I never remember seeing any actual Ahr data from the Leafs tested back then, which is why I asked. I also tried running some searches in those threads today --to no avail.

This would make sense, since that was prior to the release of bona fide CAN bus tools like Leaf Spy Pro and LEAFStat to access the actual battery data. Indeed, this is why Tony Williams and his crew conducted their miles-per-charge test on those Leafs: at the time, it was the only means available to estimate the capacity loss in them. Had they been able to extract the Ahr from the vehicles... it would have saved them a ton of time and effort, and produced more accurate results.
dhanson865 said:
Whatever the trigger logic I don't see any significant variance between the early losers and the late other than temperature and time.
Mmmm. Well... if that's true, it would mean that Nissan did not change the bar loss thresholds with its P3227 update, as promised. After all, that was supposedly the very purpose of the update: to recalibrate the capacity bar gauge.

How can we tell if a change occurred? And if so, what was the change? Without actual Ahr readouts prior to the update, its seems to me that the only solution is to compare what Nissan claimed were the thresholds in the original service manual with the real world thresholds owners are now experiencing. This is what the table on the original page MWI-23 stated, reiterated verbatim in the Nissan LEAF Wiki:

original_loss.jpg


So far, I haven't found one report of losing a capacity bar at those percentages or higher (Ahr ÷ 66.25).

Now, to give Nissan the benefit of the doubt, perhaps their technicians later discovered that their original thresholds were flat out wrong. However, if such was the case, why delete the table entirely from the service manual? Why not simply correct it with more accurate, real world thresholds, something like this, postulated from the Ahr reports in the Wiki:

real_world_loss.jpg


In my mind, that would have been more open, honest, transparent --and helpful. I might be mistaken, but I suspect that most consumers think that the thresholds specified in the original service manual and the Wiki still apply. I purport that owners deserve to know the true parameters behind Nissan's battery capacity warranty so that they can measure and anticipate their own bar losses using tools like LEAFStat and Leaf Spy Pro.

But maybe that's just me...? :|
 
I don't have a GID counter or the Leaf Spy app, but this morning I drove my 2013 Leaf with 100% charge 38.7 miles to work and I arrived with 25% remaining. When the car was new I could drive it 80miles with my driving style. Now I estimate the car has a 50mile total range, which is 63% of the original.

I haven't lost the 4th bar yet. I've driven it roughly 57600miles in 3 years. It's getting a little crazy...like I'm driving my old 4cyl commuter with a little over 1 gallon of gas all the time.
 
Sorry, this is my first post here and I have probably missed others giving the same or similar data.

Living in Phoenix and being an engineer and still waiting for the bluetooth scanner to run LeafSpy, I have had to fall back to other methods. For the last week I have been using my phone camera to record all the dash information several times during each charge/drive cycle. My home to work to home round trip is just over 13 miles. I store the Leaf outside so it gets the full brunt of the heat. However, I have been afraid of putting up my charge port for fear someone will steal the power cord to sell for copper, so it has primarily been trickle charged. I have been showing 4.0 miles/KWh since I got the car so I am not driving excessively hard.

I did not record any of this data early on so I don't know what the original, full power of the battery was. I do remember the initial (July 2014 with a 2014 Leaf) was showing 93 miles fully charged. Now, I am showing 72 miles at full charge. But by measuring distance since recharge and indicated charge state and driving down to the lowest charge levels I can be sure of getting home from to minimize extrapolation, I am getting the following.

2 Bars not showing, and I lost the second bar within the last month or so. Indicated 72 mile range on full charge, but extrapolating discharge per mile I am projecting to 55 to 62 miles at 00 charge. graphing the few runs I have so far of miles per percentage charge divided by an assumed 93 mile range of 0.93 miles/percentage point I get around 0.55 to 0.6 miles/percentage point, or about 60% of original capacity, and that is with only TWO bars down! Since several runs were down to 35 to 31% I think these as accurate numbers.

I am taking the Leaf in to Nissan for a 6 month anyway, and have already complained that the battery is way down and needs to be checked and that the bars are not tracking. It will be interesting to see what they report back. My last battery health check by them said it was fantastic, but at an EV car show someone else had a LeafSpy and said that my battery was already down quite a bit. My scanner should arrive shortly and I am looking forward to a more detailed accounting. But the reduction in miles driven before reaching very low battery levels is the ultimate tell, since the whole question is how far you can safely drive before needing to be towed to the nearest charging station. (Only happened to me once and that was because they removed a charging station between Phoenix and Tucson I had used many times before).

Sorry for the long post. Basically it comes down to 34.1 miles with charge down to 35%, only two bars showing on a 3y old battery, fairly gently used.

Mike

Edit:
OBDII scanner came in, paired with LeafSpy.

72.1% SOC
12.2Kwh 36.61Ah

101.1 F
45.5 m -> 5%
157 GID (55.9%)
384.9V 15mv

Bat stats AH 50.79
SOH 77%
Hx 68.75%
odo 19790 24 QC 519 L1/L2

If SOH is the internally generated battery condition, it could be the one to drive the battery display with only 2 bars gone. However I wonder how they generate a number that is so far from the mileage drop down to 50-65% that I can't think of what they really are measuring! The Hx o 68.75% even seems a bit high from my measurements of remaining energy. I am taking it in today and I will see what they report back to me.
 
One thing I'll point out is that if Ahr / SOH were the only driving factor and they changed the bar thresholds relative to Ahr, then I'd expect to see a binary-ish split between cars which had the software upgrade done, and those that have not, in terms of AHr at 4th bar loss.
I put together my own spreadsheet of "4 bar losers" reported in these forums, and did not see any such obvious split. I did not make note of which owners had or hadn't had the update, but my recollection is that there were at least some that had not.

For 2011/2012 models, the lowest drop I saw was at 61.35% SOH / 40.6 Ahr, the highest was at 65.65% SOH / 43.47 Ahr (both SOH numbers assuming 100%=66.25Ahr). Most were clumped towards the higher values. (edit: remove my mistake re: originally published thresholds from Nissan)

Linking images is a bit of a pain but you can see a couple representations here and here.

-Eric
 
What if the capacity bars are triggered off of the voltage levels? They have the state of health and charge capacity stats already. What if there's an expected voltage level at certain AHr, and the capacity bar thresholds are based on how far off the voltage is relative to the 100% voltage level? It definitely can't be a straight percentage, since people have reported losing bars within a narrow range of percentages. This way, you can have the same voltage triggered without regards to the AHr capacity of the batteries, and why the bars are not dropping where we expected it to. Not likely?
 
Well, I finally got the car back, and not surprisingly they said they battery is fine. But the test was so abysmal it is frightening. They said they charged the battery up over night to make sure it was at max, then looked at the 'fuel' gauge to see that it predicted 78 miles. They recommended that I drive more gently so that I won't be so limited in range with my 4.0m/KWh! In my measurements, it often started with a very grandiose 'estimate' of range, and as I drove the estimate fell a lot faster than the trip odometer went up. I specifically avoided making any deductions based on the estimated range with few actual miles driven. The previous week started with 82 miles at 99% charge, but at the end with only 35% charge left and only 34.1 miles on the trip it still promised 26 miles further range! But if the charge gauge is even moderately close to linear, with 2/3 charge gone and only 1/3 left, it should only be able to go half as far as it had gone already, or 14 miles. And the sum of trip odometer miles and estimated range miles constantly dropped, so it was clear to me at least that reading the estimated range on a full charge did not mean much.

But with only 2 bars gone it did not really matter much anyway. Nissan won't replace it unless there are 4 bars gone, no matter what battery condition that takes to make it give up the 4th bar.

The Nissan webiste claims it will cover loss of capacity until 96 months or 100,000 miles https://www.nissanusa.com/electric-cars/leaf/charging-range/battery/ But there is "*" at the end of that promise, and I could not find the footnote that explains it. And then I noticed it was talking about the 30Kwh battery, which leaves all us early adopters out in the cold. Still I am glad I got my Leaf. I have wanted an electric car for a very long time, and this is one of the prices of being an early adopter.

Mike
 
mwbushroe1 said:
But with only 2 bars gone it did not really matter much anyway. Nissan won't replace it unless there are 4 bars gone, no matter what battery condition that takes to make it give up the 4th bar.

The Nissan webiste claims it will cover loss of capacity until 96 months or 100,000 miles https://www.nissanusa.com/electric-cars/leaf/charging-range/battery/ But there is "*" at the end of that promise, and I could not find the footnote that explains it. And then I noticed it was talking about the 30Kwh battery, which leaves all us early adopters out in the cold.
Your earlier posts said you have a '14. If that's all you have, your capacity warranty is for 5 years/60K miles, which is the case for all 24 kWh Leafs (all '11 thru '15). You must be down to 4 bars or less before either 5 years and 60K miles and the condition must be verified by a Nissan dealer.

The terms are in your warranty booklet.
 
I have been having trouble nailing down exactly what my warranty is. When I switched from 36 month lease to another 60 months purchase, the only pamphlet I got was for the Platinum level used car coverage, which specifically excludes "Hybrid/High voltage/Lithium battery pack. So the actual warranty on the traction battery must be somewhere else. I kept asking t the dealership for copy of my coverage but never got one. I wonder if I can get something directly from Nissan headquarters?
 
mwbushroe, you're an engineer, you should now crap data in will only give you crap results. Your battery warranty is 5yrs/60k miles to lose 4 bars. A quick google search will give you your 2014 warranty booklet. Your battery is behaving normally for phoenix. Your testing and extrapolation methods pre-leafspy were awful and provide nothing usable. You will easily meet the conditions for a warranty battery replacement when you drop your 4th bar, so be happy.

Edit: It's called a "guess o' meter" for a reason, the top end number really means nothing.
 
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