2020 57k Miles Failed Cell Warranty Advice CVLI Test

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Oct 2, 2016
I've got a 2020 non-plus 40kWh with a failed cell.

We have a bit of an up-hill to our house. A couple days ago, I was driving home with 56% SOC. When we hit the incline, the SOC dropped like a rock, started giving low charge warnings, and went into turtle mode. That was all in the span of less than two miles at about 40-50 MPH. When I pulled into the driveway, just sitting in park, the SOC climbed back up to >50%.

I was able to repeat the issue on video. A day or so later, I took it on the highway. One minute I have 99 miles of range and the next I'm at zero.

Discussions on this forums confirmed to me that this is a battery issue and that I should seek a warranty fix. I was hopint that the community would collaborate on some advice of how to reach out to the dealers and what to expect. I was planning on contacting a couple of them and try to get a sense of who might be best to trust this issue with.

Hopefully you all han help guide me through a good warranty experience and that can be shared here for others.

That's a MASSIVE delta for such a high SoC.

You'll need the dealer to do a CVLI test but for the 40 kWh pack. Google for site:mynissanleaf.com cvli. The voltage may be different than listed at https://www.mynissanleaf.com/viewtopic.php?t=16070 since that was for the 24 kWh pack w/different cells.
cwerdna said:
You'll need the dealer to do a CVLI test

Thanks for the reply. Good info. Sounds like my issue might be more novel that I thought.

Is there any experience of how to best choose what dealership to work with? I'm on the west side of Portland, Oregon. There are at least 3 dealerships that are close enough to work with. When we purchased, I started with the closest one and worked my way out. I communicated with 4 dealerships and ended up buying with the 3rd one. By far, they provided the best purchase arrangement. I was actually concerned that I was missing some fine-print 'gotcha' because they were so much better than the others.

I figured that I'd at least reach out to the closest one and the one that we purchased from and try to decide who is best equipped or most willing to provide a good result.

This car went from rock-solid to practically unusable overnight. Do people end up with a loaner car while they wait to get their leaf batteries fixed?

If that delta gets large enough the BMS will prevent the battery from starting. At least that is what happened in my 2013 at somewhere around 600 mv delta. Mine had a "fully charged" battery that would not even give me a turtle--lucky it happened at home. You will be left with the pack at high SOC and no way to lower it to good storage levels.

Definitely find out which dealer is good at working on these. Try every discussion board out there. Getting good service on this all comes down to the dealer and there is a huge bell curve like distribution of great all the way down to very bad. I've read about great a lot here, and experienced very very bad myself.
Here is when took about a two mile trip to try and reproduce what had just happened.

Update: I emailed a used car dealer who specializes in EVs (PlattAuto.com). I bought my first Leaf from them and I trust them. In the email I asked their opinion of the local dealerships for warranty battery work.

I don't see any mention of LeafSpy in your replies/posts...so I thought I would throw this out there.
The only way to get a dealer to do anything with the battery pack (warranty or otherwise) is if it throws DTCs...and you need LeafSpy to prove those DTCs (assuming they exist). From personal experience, dealers don't like to open up battery packs (only sell you a new one), and finding qualified (EV) repair shops can be difficult. I did this (on my own nickel) a couple years ago for my 40 kWh pack and it's not fun.
Once my car generated a service light and stored DTC codes Nissan and my dealer changed the weak cell.

Yes, my dealer had a properly trained tech and he did a good job at replacing the defected cell module. They would not do anything until it generated a DTC code. Keep divining it and it will eventually store a code.
I got turtle mode, service EV and stored codes from my weak cell. I was able to restart and drive to dealer in turtle mode...although with reduced power and max speed of about 50 mph.
LeftieBiker said:
MarkCoburn said:
I'm a bit worried that the car is just going to go into an error mode and completely shutdown.
Before that happens, you should get DTCs.

With my 2013, I had one cell that died over about three weeks--looking just like the OP's. When the delta got to around 600 mv the car would not go into drive mode, and would not even close the main relay in the traction battery. I saw elsewhere on MNL that 500 mv may be the go/no go limit. It is possible that the first DTC on this will coincide with a no drive condition. I should have grabbed the codes on this event, but it was not until later when looking at LS screen shots that I realized what had happened. All I knew is that a) the car would not close the relay in the traction battery, and b) I had to get the battery out and draw off some charge soon. These worked great for getting the car far enough up to safely work under it : https://myliftstand.com/
These worked great for getting the car far enough up to safely work under it : https://myliftstand.com/

Those are some nice but expensive jack stands.
The car is at Dick Hannah Nissan in Gladstone on the east side of Portland, Oregon. They came highly recommended by Platt Auto who we bought our first used Leaf from and whom I think is a highly trustworthy used EV dealer.

Statements from our service manager:
  • I left my bluetooth ODB2 reader in the ODB2 port and they said that was a bit of an issue. He said that the tech says that it wipes the history so they have to rebuild the data by running the battery down and re-charging it. He also said that it shouldn't be left there because it messes with a bunch of the data signals. I don't know. I never herd that before. I used to run it all the time in our gen1 Leaf. For this one, I never thought to plug it in until we started having problems, about a week ago.
  • They seem to think that our issue is going to be a pretty clear case of a warranty fix. For the record, I never had any Service Soon or otherwise errors. Just what is shown in the video where charge % would drop like a rock.
    The SM also indicated that Nissan are doing several things for owners when this happens.
    1. Replace just the bad module(s)
    2. Replace the whole battery. This might happen, not just because the whole battery needs changed. Sometimes, a replacement battery is available but the modules are on back-order, so we would get an entire battery,
    3. If supply issues keep it from being fixed soon, there are some "long-term" options. Some have just been put in long-term loaners. Others have been bought-out. He specifically mentioned some moving to a new Ariya with Nissan's help.

Currently we are in a loaner (new Altima SR AWD). He said that it will be at least a week.
Those are some nice but expensive jack stands.

I get nervous working in a crush zone like being under a car. Also I have a fear of being underground too! I trust those stands. I will get a lift someday when I get the barn finished.

Congrats on finding a good dealer! They really should just drop the battery and replace the module--but who knows.
Those are really nice jack stands--will keep them in mind. I have a lift in my workshop/garage, but hope I never need to take the battery out. I try to remember to remove the Bluetooth adapter from the OBDII port before turning the car in for service at the dealer, but have never had it delete information unless I specifically cleared the codes. I also remove it if the car will be parked for more than a couple days. Otherwise, it remains plugged in all the time. Since there appears to be only one bad cell group, I expect OP's car will be repaired by replacing the module containing that cell group.