Weak cell #44 in 2013 Leaf--where in pack?

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MikeinPA

Well-known member
Joined
Jul 8, 2015
Messages
215
Location
Pennsylvania
Picked up a 7/2013 (manufacturing date) Leaf with 16 K miles to go with my other 2013 Leaf last Friday.

It's a two bar loser and Leaf Spy shows 75% SOH. Leaf Spy is also showing cell #44 is discharging faster than the rest of the pack; at VLBW #44 is about 100 mv below the next lowest cell, overall voltage spread ~200 mv. (I will edit this post to add an screen shot.) At 100% charge through about 50% charge, #44 is tracking pretty well with the rest of the pack.

Does anyone have a reference for where cell #44 is in this pack? I will probably try replacing #44 if it doesn't give a P33E6 fault some time over the next 18 months. Dropping the pack doesn't look difficult, prying the lid off does, and depending on where #44 is it could be easy or really difficult to change.

Alternatively, has anyone paid the Nissan dealership to replace cell (rather than have it done under the 8 year hardware warranty)?

So currently I am limited to about 12 kwh of capacity. It is cold here and the pack has only been cycled 4 times so far since I got it and I believe it was parked for a while before that. See if it improves. Pack is showing three temp bars, but I can still get 4 regen bubbles at times. My commute is just 6 miles each way. The 7/2013 is in very clean condition (looks new actually) and was kept in Tampa until recently. I think it must have been in a garage, no sun damage, no salt corrosion. Some white sand in wheel well though! For me, range is just not an issue, but maintainability is, so this completely un-corroded car is a happy find for me.
 
Cell #44 should be in module 22

leaf-battery-module-diagram.jpg
 
You really should get it done for free under warranty instead of opening the pack yourself and potentially causing new problems. There no way in hell I'd be DIY while still under the 8 year/100K battery defects warranty.

Google for site:mynissanleaf.com cvli. There have been a few cases where a bad module's been replaced. Example: https://www.mynissanleaf.com/viewtopic.php?t=21700.
 
Dala, excellent. Earlier this week I reviewed you pack rebuild over at Japtoys, searching for info on cell locations.

I would love it if Nissan would fix the cell, but after reviewing threads here, I though they would only do that if the P33E6 fault appeared, which I have assumed means there would be an "engine" fault light. No faults yet on dashbaord; I have tried to read the DTC codes with LS Pro, but I think it is a) hanging during the read process or b) there are no fault codes. I was going to contact Turbo3 to see what I am doing wrong. Could be the dongle.

LS Pro did report #44 as "weak" cell once so far when below VLBW, pack has failed Nissan's test procedure. Is there consensus on whether Nissan would treat this as a warranty issue even without the P33E6?

Thanks in advance for any tips on how to get this fixed by Nissan.
 
Update on this 2013 Leaf with bad cell #44. Car is in "limited power" mode most of the time, turtle on the dash. The first time I turtled it I had just gotten home and the dashboard indicated pack was near 5% and the bad cell was at around 3.3 V. At this time I also got the warning light (the car with the exclamation point through it). Warning light is permanent. I haven't been able to get Leaf Spy Pro to work with the dongle I have--using the lite version--so have not been able to access DTCs, but I am assuming the turtle and warning light are about the bad cell and not some other fault.

Funny, even with the steep hills locally, turtle is OK! Speed limits are mostly 30 mph, and it is very relaxing....

So this is now a battery warranty issue covered by the 8 year warranty. My new question is, when the dealer does the repair work, do they have to pay the costs, or are they reimbursed by Nissan for the work? TIA.
 
Nissan will reimburse them the warranty work, fingers crossed that they refresh the whole pack instead of taking it apart!
 
MikeinPA said:
Update on this 2013 Leaf with bad cell #44. Car is in "limited power" mode most of the time, turtle on the dash. The first time I turtled it I had just gotten home and the dashboard indicated pack was near 5% and the bad cell was at around 3.3 V. At this time I also got the warning light (the car with the exclamation point through it). Warning light is permanent. I haven't been able to get Leaf Spy Pro to work with the dongle I have--using the lite version--so have not been able to access DTCs, but I am assuming the turtle and warning light are about the bad cell and not some other fault.

Funny, even with the steep hills locally, turtle is OK! Speed limits are mostly 30 mph, and it is very relaxing....

So this is now a battery warranty issue covered by the 8 year warranty. My new question is, when the dealer does the repair work, do they have to pay the costs, or are they reimbursed by Nissan for the work? TIA.

At some point, the car is likely to discharge the weak cell enough to just cut off power, and leave you stranded. Just want you to know, since that could be inconvenient (or dangerous, if on the highway, etc).

Yes, this should be a warranty issue. Nissan reimburses them. Good luck! Some dealers are able to resolve these issues quickly and without fuss, others will try to say that it's not a warranty issue and generally are incompetent. Hopefully you get the former, rather than the latter. If you get a runaround, try another dealer.
 
MikeinPA said:
..with the exclamation point through it). Warning light is permanent. I haven't been able to get Leaf Spy Pro to work with the dongle I have--using the lite version--so have not been able to access DTCs, but I am assuming the turtle and warning light are about the bad cell and not some other fault.

Can you get a cell voltage reading of the max/min difference? How much lower is #44 than the average? Are there any other weak cells showing up that are sagging more than the rest. Does it still charge up to 12 bars full or does it stop sooner with less bars?

A weak or worn out cell generally has a dimished capacity, which looks like a voltage sag when under load, and appears as a higher voltage during chargging.

A defective or failed cell could appears as either a short or partial internal short, or as an open.

Whichever the case it's a nuisance to deal with, hopefully they will warrant the pack for you.
 
Good point nlspace, I should document what it is doing and post here so there is a record of what voltages are causing the fault (if it is the weak cell and not another issue). I have been checking the weak cell with LS while driving (to make sure it isn't in worse condition), and the behavior under discharge is the same as 4 months ago. #44 drops faster than the rest, and the lowest cell is what the % charge reflects (the GOM cacthes up too, but its the GOM, who knows what it is thinking). I do not know why it decided to have turtles and also get the "check car" warning light--except it was very low one day, and I had time to put about 4 kwh into it, and this was the first time I saw the "check car" light.
 
Update on the 2013 with bad cell at#44. I took it in a month ago, May 20, and they saw two codes, one for the battery and one for the water pump. They said Nissan advises replace the water pump first for $880, which after some quick checking I said go ahead--even though the pump is easy to change and a few hundred bucks on line. I thought let them get on with the process and we will get to the battery soon enough. They then cleared the codes, and I drove it home. The EV warning light and turtle came on two days later, after about 12 miles actual driving. With covid and other stuff it was until two weeks before I got it back there. They saw the P33E6 code, and their paperwork includes that code, but for some reason wanted to replace the BMS in the pack for $1600.

Call to Nissan EV line made. I have talked to the nice people there several times, and the dealership too. As of yesterday, they have confirmed to me repeatedly that they will not cover this under the 8 years materials and workmanship, which is very weird. If it is the cell or the BMS, it is still the battery, and the warranty on materials and workmanship would apply. They are working on getting some dollar relief on the $1600 BMS replacement, but based on the rest of the conversations with them I am not hopeful.
 
Further update. Today I charged the car to 100% (something I very rarely do, see note below)(at this point I am ready to try anything), let it finish, and looked at the cell balance--flat bar graph as expected, 20 mv difference--nothing new here, the imbalance shows up around 50% SOC. Verified that EV warning and turtle symbols are present. Then I left it parked but in ready-to-drive mode and checked it every hour to see if it somehow could stay balanced as it slowly discharged despite the tiny shunt resistors. After ~4 hours it is down to 90% on Leaf Spy--this is right after the comment I left above. I am checking the bar graph on LS, not looking at the dashboard. Imagine my surprise when I do look at the dash and both the EV warning symbol and the turtle are gone. I drove it gently for 15 miles and no symbols and no imbalance yet (20 mv). I am surprised to see it removed those symbols on its own. I don’t think cell #44 is miraculously healed, but I am curious if anyone has insight into why the dash warnings would clear up. Also I still do not have a working OBD device for Leaf Spy Pro--a new BAFX dongle did not connect. Any suggestions? Phone is a Pixel 3xl.

Note: I keep the SOC centered around 50% on the white 2013 because I don't really need the range and there are papers out there showing aging really slows for this chemistry at low SOC and cooler temps. I can still get 80 miles range easily with this car, and in fact had nearly 90 miles range last year on the turnpike, and that is plenty for us. We rent vehicles for long trips. I have been doing the same for the blue one and that may have been worsening the imbalance--nay, almost certainly has.

After 100% charge: https://imgshare.io/images/2020/06/21/Screenshot_20200620-130859.png
 
Maybe this one is a BMS issue, although I wouldn't trust the dealership on that. Maybe the BMS is falsely reporting one or more dangerously low voltages for one or more cells, triggering the warnings.
 
Yes, something flaky in the BMS would fit the symptoms. This agrees with what the dealer ship said a month ago, that quote "Nissan wants us to open the pack and read the cell voltages". That statement made no sense to me at the time.
 
Leftie, starting to look like the BMS is confused.

This morning turned car on and EV warning light and turtle are back. Drove it 7 miles locally on flat, 30 mph roads, parked for 3 hours in the ready to drive state, still turtle at end of this. Power off and back on, EV warning light and turtle are gone. Pack is at 69% SOC, min/avg/max 3.977/4.003/4.010, cell #44 at 3.987, cells #91 and 92 at 3.977 and 3.983 respectively.

Isn't 4.00 volts per cell high for a resting 1/3 discharged Leaf AESC cell? I will check the other car.

Also, what is the best way to put images up here?

Screenshot_20200621-155403.png


https://imgshare.io/image/N5iZNO

https://imgshare.io/images/2020/06/21/Screenshot_20200621-155403.png

Screenshot_20200621-155403.png
 
Link the images using the url of the image at the hosting site and the "IMAGE" option in the posting window here.

I guess it's down to two possibilities: bad BMS or bad cells. And as I've said, I don't think we've ever seen bad cells manifested by higher voltages... How about it folks? I just woke up, and my brain is mushier than oatmeal. Is this the first time we've seen this? If the BMS is glitchy "locally" rather than "globally" would that manifest like this?
 
LeftieBiker said:
Link the images using the url of the image at the hosting site and the "IMAGE" option in the posting window here.

I guess it's down to two possibilities: bad BMS or bad cells. And as I've said, I don't think we've ever seen bad cells manifested by higher voltages... How about it folks? I just woke up, and my brain is mushier than oatmeal. Is this the first time we've seen this? If the BMS is glitchy "locally" rather than "globally" would that manifest like this?

Don't open the battery yourself. That will void the warranty.

I just checked my 2011 Leaf (with a 2015 pack and 2015 BMS). At 72% SOC, I'm showing the average voltage to be 4.021V, minimum 4.017 and maximum 4.026 (9mv min/max). I do not believe your cells are overcharged.

It's crazy that they won't cover this under warranty. This is clearly a failure of the lithium ion battery. Do you have to call the EV help line for coverage info? Can you just work through the dealership? Is the dealership referring you to the EV help line for something?

Hey Nissan: This is why Tesla is eating you alive. They've built plenty of faulty stuff, but they back it up and fix the issues.

I would get a video of the behavior of your car when it goes into turtle suddenly. I would take a copy of the video into the dealership along with a printed copy of the warranty booklet, and tell them this is a safety issue resulting from a faulty battery. If they refuse, I would ask which specific criteria excludes this from being a warranty issue. Get everything in writing.

I would then take the car to another dealership in your area with a good reputation. See if they can somehow get something done. If not, I would get the rejection in writing from them as well. It's really absurd--I've seen a number of people post on the forums with problems and symptoms very similar to yours, and they got the battery repaired in days.

If you get rejected at all dealerships, you have three options:
1) Sue Nissan
2) Sell the car
3) Repair or replace the battery pack yourself. You could buy a new pack from Nissan for $5500, or replace it with a different pack from a junkyard, or replace the cell. Doing this will void the warranty.

I've seen a post from a guy who went through similar conditions to you. It was hellish, and he did end up suing. He came back to post that the issue was "resolved" and he was "happy with the outcome" and would have "nothing more to add". (i.e. he settled and got what he was looking for).


From: https://owners.nissanusa.com/content/techpub/ManualsAndGuides/LEAF/2013/2013-LEAF-warranty-booklet.pdf
LITHIUM–ION BATTERY COVERAGE
The Lithium-Ion coverage period is 96 months or 100,000 miles, whichever comes first. This warranty covers any repairs needed to correct defects in materials or workmanship subject to the exclusions listed under the heading WHATISNOTCOVERED. This warranty period is 96 months or 100,000 miles, whichever comes first.

LITHIUM-ION BATTERY
This warranty does not cover damage or failures resulting from or caused by:
Exposing a vehicle to ambient temperatures above120F (49C) for over 24 hours.
Storing a vehicle in temperatures below -13F (-25C)for over seven days.
Leaving your vehicle for over 14 days where the lithium-ion battery reaches a zero or near zero state of charge.
Physically damaging the lithium-ion battery or intentionally attempting to reduce the life of the lithium-ion battery.
Exposing the lithium-ion battery to contact with a direct flame.
Immersing any portion of the lithium-ion battery in water or fluids.
Opening the lithium-ion battery enclosure or having it serviced by someone other than a Nissan LEAF certified technician.
Neglecting to follow correct charging procedures. Use of incompatible charging devices. Consequential damage caused by the failure to re-pair an existing problem.

GRADUAL CAPACITY LOSS
The Lithium-ion battery (EV battery), like all lithium-ion batteries, will experience gradual capacity loss with time and use. Loss of battery capacity due to or resulting from gradual capacity loss is NOT covered under this warranty beyond the terms and limits specified in the LITHIUM-ION BATTERY CAPACITY COVERAGE above. See your OWNER’S MANUAL for important tips on how to maximize the life and capacity of the “Lithium-ion battery.”
 
They are splitting hairs by saying that the BMS isn't part of the "battery." Technically, it isn't (my Vectrix has no BMS, despite using Leaf modules), but it is contained within the battery shell. This definitely isn't one to try at home with no similar experience, but anyone who has done a battery module swap (not "just" a pack swap) with a Leaf should be able to handle it.
 
LeftieBiker said:
They are splitting hairs by saying that the BMS isn't part of the "battery." Technically, it isn't (my Vectrix has no BMS, despite using Leaf modules), but it is contained within the battery shell. This definitely isn't one to try at home with no similar experience, but anyone who has done a battery module swap (not "just" a pack swap) with a Leaf should be able to handle it.

Ah. I see. The lithium ion battery coverage doesn't enumerate the components covered. However, the BMS is not listed under the drivetrain or EV system. So if they wanted to say it wasn't part of the battery, given it's inside the pack and replaced as part of a new battery, I would ask what other system it's covered under, and challenge any attempts to categorize it as such since it's not enumerated. Just my 2c.

Personally, I feel, unless clarified somewhere I missed, that the BMS is definitely part of the lithium ion battery pack.
 
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