Capacity Loss on 2011-2012 LEAFs

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Amped said:
Lost bar #4 today. 2012 SL. Warranty up on 11/15.

Nick of time! That's an interestingly high Hx. Have you had the software update done? When was the car built?
I'm down to 43.6 Ahr so seeing 43.21 is encouraging, though I wonder if you may have a slightly different battery given the different Hx numbers.
 
sandeen said:
Amped said:
Lost bar #4 today. 2012 SL. Warranty up on 11/15.

Nick of time! That's an interestingly high Hx. Have you had the software update done? When was the car built?
I'm down to 43.6 Ahr so seeing 43.21 is encouraging, though I wonder if you may have a slightly different battery given the different Hx numbers.

Build date is Jan 2012. I've had the P3227 update last September. The Ahr has bounced around a bit for months. It was at 44.16 on 9/16, 42.91 on 9/17 and now 43.21 on 9/20. I drove it a lot over the weekend with 4 QCs. Overall, the car has had only 58 QCs.
 
Amped said:
It was at 44.16 on 9/16, 42.91 on 9/17 and now 43.21 on 9/20. I drove it a lot over the weekend with 4 QCs. Overall, the car has had only 58 QCs.
It dropped by 1.25Ahr in one day? Crazy.
 
I have no idea what it may mean, but Amped's Hx-vs-Ahr is more inline with the 2013 numbers than 2012.
Three other 2011/2012 cars had similarly high Hx values; Newmanji (57.89), Brian0123 (58.44), and sksingh (58.45). In general Ahr-vs-Hx is linear, with the 2013 cars showing more or less the same slope as 2011/2012, but with Hx values higher by about 15 points.
Funky that 4 out of 75 2011/12 4-bar-losers have Hx more in line with 2013 numbers. I think this confirms that Ahr is the value to pay attention to for drop predictions, not Hx.

RpfgFaF.png

(p.s. do people find this interesting, or should I stop with the graphs, already?) :)
 
Being an engineer, I always like graphs!

Such a marked difference in HX between years - like you, I wonder why - is it simply a measurement (or definition) issue, an actual chemistry change, tweaks in battery operating parameters "all the above"? Also wonder if the rate of battery degradation (under very similar operating conditions - likely impossible to assess) is better in the 2013 model batteries or is it just the time factor of using up the battery faster (2013 models) that results in the 4th bar drop. The marked difference and such precise correlation with ahrs suggests an actual battery/system change.
 
I'm just now seeing this thread, and I apologize, I should have posted here. My battery was replaced last week by Nissan with 20%/80% owner/dealer payment. I got the car second hand and the original owner tells me it just lost the 9th bar earlier in the year, but don't have exact date or KW details on it. I did take a snapshot of LeafSpy before/after the install at 59k mi:

Before install: AHr=42.42 SOH=64% Hx=43/47%
 
sandeen said:
I have no idea what it may mean, but Amped's Hx-vs-Ahr is more inline with the 2013 numbers than 2012.
Three other 2011/2012 cars had similarly high Hx values; Newmanji (57.89), Brian0123 (58.44), and sksingh (58.45). In general Ahr-vs-Hx is linear, with the 2013 cars showing more or less the same slope as 2011/2012, but with Hx values higher by about 15 points.
Funky that 4 out of 75 2011/12 4-bar-losers have Hx more in line with 2013 numbers. I think this confirms that Ahr is the value to pay attention to for drop predictions, not Hx.

RpfgFaF.png

(p.s. do people find this interesting, or should I stop with the graphs, already?) :)


I've never quite understood Hx and what it represents. But, I love graphs.
 
Supersleeper said:
My battery was replaced last week by Nissan with 20%/80% owner/dealer payment. I got the car second hand and the original owner tells me it just lost the 9th bar earlier in the year ...
Wow, so you bought it second hand, already down to 8 bars, and Nissan cut you a deal?
 
sandeen said:
I have no idea what it may mean, but Amped's Hx-vs-Ahr is more inline with the 2013 numbers than 2012.
I suspect that '11-12 LEAFs with a high Hx/AHr ratio don't have the P3227 update. Many people reported a drop in Hx numbers after the update along with a corresponding drop in maximum allowed regenerative braking.
 
drees said:
sandeen said:
I have no idea what it may mean, but Amped's Hx-vs-Ahr is more inline with the 2013 numbers than 2012.
I suspect that '11-12 LEAFs with a high Hx/AHr ratio don't have the P3227 update. Many people reported a drop in Hx numbers after the update along with a corresponding drop in maximum allowed regenerative braking.
Agreed, as I communicated to sandeen a few weeks ago in a PM:
RegGuheert said:
sandeen said:
It's interesting that a couple of them had /much/ higher Hx numbers... not sure what that means.
Likely that is due to not having the P3227 update applied. Take a look at my plot of Capacity and Hx before and after the P3227 update was applied:

http://www.mynissanleaf.com/viewtopic.php?f=30&t=14807&start=130#p408657
 
drees said:
I suspect that '11-12 LEAFs with a high Hx/AHr ratio don't have the P3227 update. Many people reported a drop in Hx numbers after the update along with a corresponding drop in maximum allowed regenerative braking.

That's why I asked Amped about that detail, but that car did have the update done last September.

Edit: sksingh had it done as well.

Edit2: But maybe they were botched upgrades? RegGuheert's graph does make it look like Hx was nearly tracking SOH (is that the same as Capacity on your graph?) prior to the upgrade.

Edit3: Looks like TickTock's HX did drop by ~15 points immediately after the P3227 update.
(I don't know why I'm even spending time on this) :)
 
Sandeen;
The graph points for my Leaf (42.59 ahrs/43.76%Hx), followed having an official "battery report" done by the dealer (actually several months before the replacement). I was told that included the "update". Is there a way to confirm through actual records?
 
Marktm said:
Sandeen;
The graph points for my Leaf (42.59 ahrs/43.76%Hx), followed having an official "battery report" done by the dealer (actually several months before the replacement). I was told that included the "update". Is there a way to confirm through actual records?
The dealer or Nissan corporate can tell you if it was done, but others have said that the Nissan recall campaign check website will tell you if the update is still outstanding, as well.
 
sandeen said:
Edit2: But maybe they were botched upgrades? RegGuheert's graph does make it look like Hx was nearly tracking SOH (is that the same as Capacity on your graph?) prior to the upgrade.
Yes, my "Capacity" is percent of original capacity remaining, which should be the same as SOH. BTW, notice that Hx is roughly SOH^2 following the P3227 Update.
Marktm said:
Sandeen;
The graph points for my Leaf (42.59 ahrs/43.76%Hx), followed having an official "battery report" done by the dealer (actually several months before the replacement). I was told that included the "update". Is there a way to confirm through actual records?
Nissan is not supposed to replace ANY battery until after the P3227 update has been applied, so the fact that your battery was replaced makes me think it was applied. And since your Hx is roughly SOH^2, I'd say you had P3227 applied. (0.643^2 = 0.413)

Your paperwork from the dealership should also indicate that P3227 was applied.
 
I bought a 2012 SL back in June with 9 bars, with warranty expiring on October 10. Leaf Spy shows SOH at 67% with 44.35 AHr. After quick charging twice a day the past couple weeks, AHr went up to 44.46! Has anyone experienced AHr going up after quick charging? Called Nissan and they said they don't do any out of warranty free or cost sharing battery replacement anymore. Don't think I'm going to make it.
 
cyberyeh said:
I bought a 2012 SL back in June with 9 bars, with warranty expiring on October 10. Leaf Spy shows SOH at 67% with 44.35 AHr. After quick charging twice a day the past couple weeks, AHr went up to 44.46! Has anyone experienced AHr going up after quick charging? Called Nissan and they said they don't do any out of warranty free or cost sharing battery replacement anymore. Don't think I'm going to make it.

the QC bump is normal and temporary. Let it sit a few days or simply don't drive it a lot and it will drop back down. How hot did you get it? With the minimal amount of time you have left, I would think heat is your only chance
 
cyberyeh said:
I bought a 2012 SL back in June with 9 bars, with warranty expiring on October 10. Leaf Spy shows SOH at 67% with 44.35 AHr. After quick charging twice a day the past couple weeks, AHr went up to 44.46! Has anyone experienced AHr going up after quick charging? Called Nissan and they said they don't do any out of warranty free or cost sharing battery replacement anymore. Don't think I'm going to make it.

While QC-ing may help in hot weather to hurry along degradation (but increasing battery heating), there is evidence, as you see, that in normal temps it may be rather unhelpfully helpful, by lowering internal resistance, even if only temporarily...
 
I moved to San Diego after I bought the car in LA, and it's been quite cool this summer, and it's been around mid 70's lately. I've been driving the car and quick charging this past few weeks, and the battery gets to around 100 F, AHr went down 44.12 today. Maybe I should just let it sit a few days fully charged and see if it'll go down more than quick charging. I've read another thread that someone get a free battery after warranty expired by going through BBB, is that possible?
 
cyberyeh said:
I moved to San Diego after I bought the car in LA, and it's been quite cool this summer, and it's been around mid 70's lately. I've been driving the car and quick charging this past few weeks, and the battery gets to around 100 F, AHr went down 44.12 today. Maybe I should just let it sit a few days fully charged and see if it'll go down more than quick charging. I've read another thread that someone get a free battery after warranty expired by going through BBB, is that possible?


If you are going to do the fully charged in the Sun thing, you need to drive enough to QC 3-4 times first. Heat that pack to 10-11 TBs then fully charge it on L2 and let it sit in an asphalt parking lot.
 
DaveinOlyWA said:
If you are going to do the fully charged in the Sun thing, you need to drive enough to QC 3-4 times first. Heat that pack to 10-11 TBs then fully charge it on L2 and let it sit in an asphalt parking lot.
Wow, this is just ridiculous. I'm not saying this advice won't work, and I feel for fellow LEAF drivers with diminished battery capacity, but EV drivers shouldn't have to become experts in battery destruction. Yet this is exactly what Nissan's "all or nothing" warranty policy leads owners to do, now that Nissan has ended support for their horribly degraded batteries that are just outside the capacity warranty.

To be clear, I'm not blaming DaveinOlyWA for giving this advice. I'm just struck, once again, by the sheer ludicrousness of the situation. Five years ago, in late 2012, it still wasn't widely known that LEAF batteries degrade rapidly, so you can't blame those who purchased LEAFs then - this is really on Nissan. Even today, a great many buyers of new LEAFs likely have no idea how quickly they may lose capacity.

This is the sort of issue that leads to calls for more regulation. Perhaps all EV manufacturers should be forced to disclose metrics related to battery life, such as coulombic efficiency which has been shown to be a proxy for how rapidly a Li-ion battery is likely to degrade.
 
Back
Top