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JPWhite
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Re: LEAFspy says Bad Cells?! :(

Wed Jul 04, 2018 6:13 pm

Marktm wrote:This just showed up on LeafSpy. Is there a point at which "weak cells" turn into bad cells and Nissan will honor a defective battery warranty - has anyone had this happen?



I posted something similar on June 13th.

I'm monitoring to see if the the same cell weakens repeatedly or not. If it does I'll have Nissan check the battery out. I see your SOC was pretty low, so imbalances can occur at low SOC.. Just keep your eye on it.
--
JP White
http://jpwhitenissanleaf.com
Blue SL-e, Res 4/22/10, Ord 3/29/11, Del 7/30/11
110,000 Miles.
Lost 5 Capacity bars
7/18/13 (29,206), 8/25/14 (51,728), 7/12/15 (71.108), 5/12/16 (88,362), 10/17/16 (96,532)
New Battery 12/3/16 (98,956)

DaveinOlyWA
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Leaf Number: 314199
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Re: LEAFspy says Bad Cells?! :(

Wed Jul 04, 2018 7:10 pm

Marktm wrote:This just showed up on LeafSpy. Is there a point at which "weak cells" turn into bad cells and Nissan will honor a defective battery warranty - has anyone had this happen?

IMG_5986.PNG


Looks like you are a ways from a warranty claim. When you see turtle pop up at 30% SOC, then you got a claim. Seeing weak cells at a low SOC is hardly desirable but its also not unheard of. What does it look like when you are at 30% SOC?
2011 SL; 44,598 miles. 2013 S; 44,840 miles.2016 S30 deceased. 29,413 miles. 2018 S40; 11,987 miles, 485 GIDs, 37.6 kwh 110.89 Ahr , SOH 96.00, Hx 115.22
My Blog; http://daveinolywa.blogspot.com" onclick="window.open(this.href);return false;

SageBrush
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Re: LEAFspy says Bad Cells?! :(

Wed Jul 04, 2018 9:45 pm

If I am reading the numbers correctly, about 10% of range is lost due to the weak cells.
I have no idea what performance criteria Nissan uses before they agree that a battery is defective, and I am uncertain (but doubt) whether a weak cell will reduce the calculated Ahr capacity, and by extension, the battery capacity bar graph that Nissan uses for its degradation warranty.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

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JPWhite
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Re: LEAFspy says Bad Cells?! :(

Thu Jul 05, 2018 3:36 am

[quote="SageBrush] and by extension, the battery capacity bar graph that Nissan uses for its degradation warranty.[/quote]

Bad cells (by Nissan's definition, whatever that is) is covered by the standard materials and workmanship warranty, not by the degradation warranty.
--
JP White
http://jpwhitenissanleaf.com
Blue SL-e, Res 4/22/10, Ord 3/29/11, Del 7/30/11
110,000 Miles.
Lost 5 Capacity bars
7/18/13 (29,206), 8/25/14 (51,728), 7/12/15 (71.108), 5/12/16 (88,362), 10/17/16 (96,532)
New Battery 12/3/16 (98,956)

cwerdna
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Re: LEAFspy says Bad Cells?! :(

Thu Jul 05, 2018 3:50 am

DaveinOlyWA wrote:
Marktm wrote:This just showed up on LeafSpy. Is there a point at which "weak cells" turn into bad cells and Nissan will honor a defective battery warranty - has anyone had this happen?

IMG_5986.PNG


Looks like you are a ways from a warranty claim. When you see turtle pop up at 30% SOC, then you got a claim. Seeing weak cells at a low SOC is hardly desirable but its also not unheard of. What does it look like when you are at 30% SOC?

Yep.

Marktm may want to Google for site:mynissanleaf.com cvli and look at viewtopic.php?f=9&t=21700.

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

Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

SageBrush
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Location: Colorado

Re: LEAFspy says Bad Cells?! :(

Thu Jul 05, 2018 6:36 am

JPWhite wrote:[quote="SageBrush] and by extension, the battery capacity bar graph that Nissan uses for its degradation warranty.[/quote]

Bad cells (by Nissan's definition, whatever that is) is covered by the standard materials and workmanship warranty, not by the degradation warranty.[/quote][/quote]

Unless the bad cells lead to a "degradation" threshold. I tend to think they do not, at least at the level Mark showed.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

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Marktm
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Re: LEAFspy says Bad Cells?! :(

Thu Jul 05, 2018 8:19 am

cwerdna wrote:
Marktm may want to Google for site:mynissanleaf.com cvli and look at viewtopic.php?f=9&t=21700.



Interesting series of posts.

Has anyone talked with a highly knowledgeable Nissan tech guy that understands the parameters used (and the calculations based on those parameters) that determine when a battery is "defective"? NOT degraded, but defective? Having a casual understanding of FLA batteries installed in series (and experience with the resulting problems - mostly associated with no BMS), it would be interesting to understand the designers perspective - that can have a serious monetary effect to the corporation! LeafSpy has likely allowed us users to have much more information than these designers expected!
2012 Leaf SL; 36,000 miles. Battery replaced November 1st, 2016.

SageBrush
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Re: LEAFspy says Bad Cells?! :(

Thu Jul 05, 2018 8:38 am

I also found the link Cwerdna posted to be very informative. I still don't know how he keeps track or remembers but he is a fantastic resource.

"It seems to me that with one module (two cell-pairs) replaced, the battery will have an EASIER time passing the CVLI test since a cell-pair would have to drop below the mean voltage by 1.5X the amount that those new cell-pairs exceed the average voltage. In other words, you will have to have quite a bit weaker cell in order to fail that test."

That would be the defective cell test:
Average - Min > (max - average) * 1.5
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

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