The 40KWH Battery Topic

[danrjones]

In this case I'm just going for simple napkin math.

It sounds like Leafspy might be showing us about 1.5% on both the top and bottom that you cannot use.
So if we take my numbers and then adjust them, we have:

96.7-20.1% = 76.6 -> 76.6/.97 = 78.97% of useable battery

26.31 kWh /.7897 = 33.32 kWh useable battery

Degradation -> 33.32/36 = 92.5%

OR

33.32/38 = 87.6%

Most of the reports I've seen still say it is 36 useable of 40 kWh... so that means my degradation is actually around 92%.
But do I actually believe this math? Not really. Too many assumptions, unknowns and inaccuracies in my data.

[HerdingElectrons]

My recollection is that the 40kWh packs are 40.xx kWh gross & 38.6kWh is what Nissan is allowing for usable capacity. I believe I got that from a video Q&A session when the 2018 Leaf was being released that I believe Cwerdna linked to but I will have to do some digging to see if my memory is accurate

[LeftieBiker]

Most of the reports I've seen still say it is 36 useable of 40 kWh... so that means my degradation is actually around 92%.

Hopefully you mean 8% degradation, 92% remaining capacity.

[danrjones]

Most of the reports I've seen still say it is 36 useable of 40 kWh... so that means my degradation is actually around 92%.

Hopefully you mean 8% degradation, 92% remaining capacity.

Yes sorry, that was suppose to be implied by the math.

[sptleaf]

2 year update on my 2019 Leaf S

Date SOH Ahr Hx Odo # L1/L2 Days Loss
3/8/2019 99.39% 114.74 104.14% 649 24 0
3/8/2021 91.80% 105.97 94.66 12700 481 731 7.59%

when I was commuting, I would charge to 100% and not even worry about it. This last year I have let it sit without driving much at about a 70% charge. Garaged in So Cal, no Quick Charge port.

[danrjones]

My 2018 skipped its last 3 month update (would have been Dec 7th)

Checked at lunch today and sure enough, its going through an update. So even with the skipped update in December, the next update is right on the 3 month schedule. The last update was in September, and SOH went up. Now its taking away what it gave me.

As of lunch today:
SOH: 89.37
AMPHr: 103.17
Hx: 102.81

~9200 miles.

[DougWantsALeaf]

Here is a 12 bar 100K mile 40kWh Leaf.

https://youtu.be/bmcJbvmeXcM

Interestingly, he is under 85% SoH. While close, I have seen now a few places where someone is at 83-84% but still showing 12 bars. Either Nissam expanded the top bar a bit, or there is in fact a small hidden buffer.

Oddly, I am excited to see our first verified 11 bar 40kWh Leaf to understand what SoH is at that change.

[DaveinOlyWA]

Here is a 12 bar 100K mile 40kWh Leaf.

https://youtu.be/bmcJbvmeXcM

Interestingly, he is under 85% SoH. While close, I have seen now a few places where someone is at 83-84% but still showing 12 bars. Either Nissam expanded the top bar a bit, or there is in fact a small hidden buffer.

Oddly, I am excited to see our first verified 11 bar 40kWh Leaf to understand what SoH is at that change.

Not un normal for the first bar to leave at 83 something percent. What is his % of ahr? Looks like he is 84.9% of his original ahr (using 115) so, he is close. Guessing nothing will happen until its a bit warmer.

Rather see his history. Obviously not linear but what has he lost in last 2 years? Last year?

[danrjones]

My 2018 skipped its last 3 month update (would have been Dec 7th)

Checked at lunch today and sure enough, its going through an update. So even with the skipped update in December, the next update is right on the 3 month schedule. The last update was in September, and SOH went up. Now its taking away what it gave me.

As of lunch today:
SOH: 89.37
AMPHr: 103.17
Hx: 102.81

~9200 miles.

My adjustment is taking its time. Still going down as of lunch today.

SOH: 88.03%


This has been a big adjustment. I'll be blunt, I'm glad I'm getting rid of it later this year. I don't really want to try and sell it with a bar missing.
Whether the real battery degradation is 12% I don't know. I've treated the battery and car about as well as possible, except the hot summer ambient temps here. Would imagine missing a bar would make resale harder.

[DougWantsALeaf]

I wish Nissan would publish their BMS algorithm. I don't know what drives the large drops beyond general age.

My SoHs are stable right now, but I do get nervous with each quarterly update. 6 down and 3 up so far. The downs are always worse than the ups. Next quarterly for the S+ is this week...holding my breath. My charging regimen is now DC charging only on a trip when needed (sad for my NCTC), keep battery between 30% and 70% unless driving far.

https://drive.google.com/file/d/1xzcLfY ... p=drivesdk