dhanson865
Moderator
Posts: 1476
Joined: Wed May 25, 2011 7:12 am
Leaf Number: 16156
Location: Tennessee

Re: Altered capacity bar thresholds?

Fri Jun 17, 2016 10:16 am

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 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.
2012 Leaf tires 195/65/15 Dunlop Enasave 01 A/S, 15" Rims
wiki/index.php?title=Real_World_Battery_Capacity_Loss
(leaf range chart)
(efficiency 3.x KW vs 6.x KW)
please join Truedelta.com and input your repairs.

Yanquetino
Posts: 478
Joined: Tue May 11, 2010 7:47 am

Re: Altered capacity bar thresholds?

Fri Jun 17, 2016 8:24 pm

dhanson865 wrote: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 wrote: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:

Image

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:

Image

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...? :|

RCEV13
Posts: 38
Joined: Sun Feb 24, 2013 3:04 am
Delivery Date: 23 Feb 2013
Leaf Number: 401340
Location: SF Bay Area

Re: Altered capacity bar thresholds?

Thu Jun 30, 2016 8:32 am

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.

mwbushroe1
Posts: 5
Joined: Wed Jul 19, 2017 1:49 pm
Delivery Date: 05 Jul 2015
Leaf Number: 334830

Re: Altered capacity bar thresholds?

Wed Jul 19, 2017 2:23 pm

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.

sandeen
Posts: 113
Joined: Fri May 12, 2017 1:45 pm
Leaf Number: 026685
Location: Minnesota

Re: Altered capacity bar thresholds?

Fri Jul 21, 2017 1:47 pm

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
Last edited by sandeen on Fri Jul 21, 2017 3:37 pm, edited 2 times in total.
2012 SL from TX, (mfg 8/12), used, dropped to 8 bars at 43.50 Ahr, 40,601 miles. my daily stats =/= my collected data on 4-bar losers

Oils4AsphaultOnly
Gold Member
Posts: 195
Joined: Sat Oct 10, 2015 4:09 pm
Delivery Date: 20 Nov 2016
Leaf Number: 313890
Location: Arcadia, CA

Re: Altered capacity bar thresholds?

Fri Jul 21, 2017 3:04 pm

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?
[2013 leaf traded for 2016 leaf S30:
build date: Sep '16 :: purchased: Nov '16
1 May 2017 - 7300 miles & 363 GIDs
6 Sep 2017 - 13k miles & 359 GIDs]

mwbushroe1
Posts: 5
Joined: Wed Jul 19, 2017 1:49 pm
Delivery Date: 05 Jul 2015
Leaf Number: 334830

Re: Altered capacity bar thresholds?

Mon Jul 24, 2017 12:51 am

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

cwerdna
Gold Member
Posts: 7067
Joined: Fri Jun 03, 2011 4:31 pm
Delivery Date: 28 Jul 2013
Location: SF Bay Area, CA

Re: Altered capacity bar thresholds?

Mon Jul 24, 2017 1:01 am

mwbushroe1 wrote: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.

'13 blue Leaf SV w/premium package (owned)
'13 blue Leaf SV w/QC + LED & premium packages (lease over, car returned)
'06 Prius

mwbushroe1
Posts: 5
Joined: Wed Jul 19, 2017 1:49 pm
Delivery Date: 05 Jul 2015
Leaf Number: 334830

Re: Altered capacity bar thresholds?

Tue Jul 25, 2017 7:27 am

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?

rosier9
Posts: 36
Joined: Tue Mar 08, 2016 8:13 pm
Delivery Date: 09 Mar 2016
Location: Omaha, NE

Re: Altered capacity bar thresholds?

Tue Jul 25, 2017 8:12 am

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.

Return to “Batteries & Charging”