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The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 12:26 am
by Daklein
_The_ place to post battery info, SOH (state of health), Ahr (capacity), temperature observations over time, with info about how the pack is being treated, and other things relating to the new 2019+ 62kWh Plus pack. (Like the The 40kWh Topic): viewtopic.php?f=9&t=25773

There are a few stats scattered in other topics, but having this one should make it easier to keep track of them. The one I've seen is the Leaf Plus efficiency thread: viewtopic.php?f=31&t=29971 Please add Links if there are other threads with data points on the 62kWh pack. If we find ourselves bored, someone can summarize and plot the data in a google spreadsheet. :)

My pack came without a car :o :shock: :D , but it looks like it's in good shape. It came from a salvage yard near Smyrna TN, likely from a dismantled non-saleable development vehicle, allegedly with 6000 miles on it. We'll see on first discharge if it stays well balanced or not. It could always look fine top balanced but fall apart on discharge if some cells are special. I hope to get it running in the near future, and enjoy living with 62kWh! I'm curious to see if having it sitting at 91% SOC until I get it running (plus who knows how long before I got it) will impact the SOH at all.

My pack, s/n 000006 (bet I have the lowest serial number?!) estimated 6000 miles, previous history & usage unknown other than likely located in TN.
11/6/19 https://photos.app.goo.gl/QpEMnsqR91j9sXJA8
171.95 AHr
97.48 SOH
109.33 Hx

There were two other 62 packs that I checked with Leafspy also. They looked just about as good Ahr & SOH, but some external damage.
I don't know where these ended up, they were gone in less than a week after I got mine and posted here about them. https://mynissanleaf.com/viewtopic.php? ... &start=157

s/n 000015 looked just fine on Leafspy, well balanced I guess, but a couple monster dents that at least hit the cell frames.
s/n 000010 had near-zero external dents, but a broken HV connector. And it had a funny looking cell voltage histogram. Still only 16 mV spread, but showing every odd cell high and shunted, every even cell lower and not shunted. Just a curiosity. Lower SOC than the other two, could be random, but could be self discharging too. Does the BMS shunt when not charging? Bad BMS, purposely mis-balanced for a test, purposely constructed pack with half 'bad' lower capacity cells? Anyone see something like this and can explain why? https://photos.app.goo.gl/ZeWWawBPGZ6mav3y9

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 12:31 am
by LeftieBiker
With that low serial number, I'm sure that this was a test car pack of some sort. If no crash damage then it likely was in a prototype or test mule.

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 12:36 am
by Daklein
Other data points previously mentioned elsewhere:

NotATesla: Aug 2019, 6500 miles, 98% SOH (leaf plus efficiency thread)

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 5:24 am
by dmacarthur
For those of us who are not yet up to speed on the acronyms, please define SOH and explain how to find it on a Leaf Plus S, which does not have the gadgetry that the upscale models have? I was familiar with the older Leaf's 12-bar Blues icon, but that is not very sophisticated and presumably there is a better more accurate battery state read-out..... Leaf Plus mostly charging at 120V for long periods of time. Thanks!

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 7:45 am
by umdkevin
Thanks for organizing a new thread. I've been tracking my 62kWH battery degradation through LeafSpy with periodic data samples every few weeks. I plot that alongside with my mileage and add a basic linear trend, here is my latest visualization. Current reading:

11/16/2019 -- SOH 95.64 Miles 6,428

It does appear the BMS makes an adjustment every few months as others have indicated. Also appears the slop of degradation is flattening but time will tell if that's verified.

Image

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 10:48 am
by dmacarthur
How are you charging the Leaf Plus? seems like a lot of decline in a few short miles, unless it flattens nicely at roughly 95%. Is there any way to determine SOH without LeafSpy? can the dealer?

Re: The 62kWh Battery Topic

Posted: Sat Nov 16, 2019 12:44 pm
by LeftieBiker
dmacarthur wrote:
Sat Nov 16, 2019 10:48 am
How are you charging the Leaf Plus? seems like a lot of decline in a few short miles, unless it flattens nicely at roughly 95%. Is there any way to determine SOH without LeafSpy? can the dealer?
State Of Health (SOH) is a reading provided by the Battery Management System (BMS) that correlates more or less exactly to remaining battery capacity. There is a screen for battery capacity on the 40kwh SV and SL - I don't know about the S or S plus. It just shows a bar gauge with no delineation between the lines, so it looks like a linear bar. It still has the same 12 segments as the old graphic, though.

Re: The 62kWh Battery Topic

Posted: Mon Nov 18, 2019 11:05 am
by Astros
I've kept careful track of my 2018 SV and 2019 SL Plus, and they follow the exact same pattern. If you remove the 3 month drops, the remaining Ahr (from LeafSpy) follow a perfect double-linear degradation: a fairly steep (linear) decline until 7000 miles, abruptly slowing to 1/3 the degradation after that. For my 2018, that was a slope of -0.315 Ahr per 1000 miles in the fast period, and -0.087 Ahr per 1000 miles in the slow period after 7000 miles. For my 2019 Plus, the slope is slightly steeper at -0.348 Ahr per 1000 miles in the fast period and -0.113 Ahr per 1000 miles in the slow period. There is so little scatter that I assume this trend is simply programmed by Nissan.

All of that was excluding the 3 month large drops, which roughly double the degradation I've seen in both cars. I assume that the BMS does an actual check of the battery's health at that time, and applies that as a correction to the predicted degradation.

ETA: We charge mostly at home on L2, with 108 L2 and 31 L3 charges so far. We drive 20-60 miles each day mostly on the freeway (but sometimes traffic is very slow), and tend to plug in when the charge gets down to ~30%, then charge to full. We rarely use the heater, but often use defrost (or AC in the summer). The overall battery SoH (according to LeafSpy) is 96.69% at just over 10,000 miles.

Re: The 62kWh Battery Topic

Posted: Tue Nov 19, 2019 9:42 pm
by Oilpan4
Astros wrote:
Mon Nov 18, 2019 11:05 am
LeafSpy) is 96.69% at just over 10,000 miles.
That's for the 2019 plus, correct?

Re: The 62kWh Battery Topic

Posted: Wed Nov 20, 2019 9:34 am
by Astros
Oilpan4 wrote:
Tue Nov 19, 2019 9:42 pm
Astros wrote:
Mon Nov 18, 2019 11:05 am
LeafSpy) is 96.69% at just over 10,000 miles.
That's for the 2019 plus, correct?
Yes, the 2019 Plus. I had my third big battery health drop after posting that, though, so now I’m at 169.19 aHr and 95.91%.