The 40KWH Battery Topic

[jdcbomb]

The only way to now know for sure is to get a OBD2 reader and download free android Leaf Spy app (apple version costs $20!) to check SOH. BT Reader here: https://www.amazon.com/Veepeak-Blue...d=1719234097&sprefix=b011nsx27a,aps,80&sr=8-1

You can also take it into Nissan to do a battery check, but I would do the BT reader + LS app first to verify if SOH is way low, OR if there is a large imbalance.

 

[Bombastinator2]

The only way to now know for sure is to get a OBD2 reader and download free android Leaf Spy app (apple version costs $20!) to check SOH. BT Reader here: https://www.amazon.com/Veepeak-Bluetooth-Diagnostic-Supports-DashCommand/dp/B011NSX27A/ref=sr_1_1?crid=1FQBA7UE6XAV&dib=eyJ2IjoiMSJ9.F8sLBXdFO1RQlBkI9WvIog.6G97-bxLVbC3huyux-CxPm0Z06TB9X_RU01TF-qwNN8&dib_tag=se&keywords=B011NSX27A&qid=1719234097&sprefix=b011nsx27a,aps,80&sr=8-1

You can also take it into Nissan to do a battery check, but I would do the BT reader + LS app first to verify if SOH is way low, OR if there is a large imbalance.

I’ve got the app. I just don’t know what to do with it.

 

[BillAinCT]

You can also take it into Nissan to do a battery check, but I would do the BT reader + LS app first to verify if SOH is way low, OR if there is a large imbalance.

My understanding is that Nissan will only confirm the number of bars (useless since 12 is 85ish%-100%) and will not tell you anything about balance or low cells (unless they were to throw a DTC).

 

[jdcbomb]

I’ve got the app. I just don’t know what to do with it.

Do you have a BT reader dongle?

 

[Bombastinator2]

Do you have a BT reader dongle?

Yep. I can see the readouts, and I’m pretty sure an m shaped graph is bad, but I don’t know how to fix it.

 

[OntarioSV2018]

When you figure out how to read LEAFSpy, check out this spreadsheet for comparison. Someone on Reddit put it together.

 

[jdcbomb]

Yep. I can see the readouts, and I’m pretty sure an m shaped graph is bad, but I don’t know how to fix it.

Can you post a screenshot here to review?

 

[OntarioSV2018]

Yep. I can see the readouts, and I’m pretty sure an m shaped graph is bad, but I don’t know how to

It depends on the maximum difference between the cell voltages that show up as the mV on the graph.

Generally, less than 25mV below 50% SoC is good; if it ever goes above 100mV, you may be developing weak cells.
if you post a screen shot, i can let you know how it looks to me, and what to look for.

 

[Bombastinator2]

It depends on the maximum difference between the cell voltages that show up as the mV on the graph.

Generally, less than 25mV below 50% SoC is good; if it ever goes above 100mV, you may be developing weak cells.
if you post a screen shot, i can let you know how it looks to me, and what to look for.

I have gotten the impression that a graph with a big dip in it is bad. I’ve got one I think. It may not be big enough to pose a problem though. I’ve assumed there was an issue, as it looked different than just about every graph I’ve seen posted. It may not be though. Here is the pic. It actually looks less bad now than it did some time ago so it may be a self correcting thing.

 

[knightmb]

I have gotten the impression that a graph with a big dip in it is bad. I’ve got one I think. It may not be big enough to pose a problem though. I’ve assumed there was an issue, as it looked different than just about every graph I’ve seen posted. It may not be though. Here is the pic. It actually looks less bad now than it did some time ago so it may be a self correcting thing.

The 40 kWH batteries tend to have the differences a little tighter than the 62 kWH, but a high state of charge and 17 mV would not worry me because I would bet that a couple cycles of the gentle full discharge and recharge could bring those cells in closer. I would get some screen captures of what the battery looks like when you are below 20% SOC to get a battery picture of the battery health. Even better, a screenshot below 10% or when the first low battery notification comes up on the dash would work better.

 

[OntarioSV2018]

I have gotten the impression that a graph with a big dip in it is bad. I’ve got one I think. It may not be big enough to pose a problem though. I’ve assumed there was an issue, as it looked different than just about every graph I’ve seen posted. It may not be though. Here is the pic. It actually looks less bad now than it did some time ago so it may be a self correcting thing.
View attachment 4374

This is fine. your zoomed Way in your only seeing a 50 mV difference. If you tap the top half of the chart you'll zoom out and see it gets flat that's good.

Your Hx is above 80% that's a good sign no weak cells are forming. Below 60% means things are starting to go bad.

Your max cell diff is 17mV which is completely normal for a pack at 90% SoC. That number goes up when the SoC goes down. Look at the mV number when your pack is low it should be less then 30mV still if your pack is in good health.

Look at the links in the spread sheet I posted above there are lots of good analysis there and comparison for you there. Share your screen shot on the LEAF subreddit and your will probably be added to that sheet.

 

[Bombastinator2]

This is fine. your zoomed Way in your only seeing a 50 mV difference. If you tap the top half of the chart you'll zoom out and see it gets flat that's good.

Your Hx is above 80% that's a good sign no weak cells are forming. Below 60% means things are starting to go bad.

Your max cell diff is 17mV which is completely normal for a pack at 90% SoC. That number goes up when the SoC goes down. Look at the mV number when your pack is low it should be less then 30mV still if your pack is in good health.

Look at the links in the spread sheet I posted above there are lots of good analysis there and comparison for you there. Share your screen shot on the LEAF subreddit and your will probably be added to that sheet.

Heh. Thx. One more PEBKAC from me. I don’t have a Reddit account though.

 

[Bombastinator2]

My understanding is that Nissan will only confirm the number of bars (useless since 12 is 85ish%-100%) and will not tell you anything about balance or low cells (unless they were to throw a DTC).

TLDNR: stupid musings
I liked “diamond trading center” more than “diagnostic trouble code”. I enjoy absurdity sometimes. There wasn’t a highschool swim team though. With three letter acronyms there’s almost always a highschool swim team

 

[HerdingElectrons]

About to hit 90k miles... get about 5mV delta at full charge

 

[Bombastinator2]

The 40 kWH batteries tend to have the differences a little tighter than the 62 kWH, but a high state of charge and 17 mV would not worry me because I would bet that a couple cycles of the gentle full discharge and recharge could bring those cells in closer. I would get some screen captures of what the battery looks like when you are below 20% SOC to get a battery picture of the battery health. Even better, a screenshot below 10% or when the first low battery notification comes up on the dash would work better.

I will attempt this

 

[Bombastinator2]

So I attempted it. Got a 10% pic. It didn’t hit the warning but it’s 10%

 

[Bombastinator2]

 

[decimal]

Going past 90,000 miles now...
LS stats:
AHr... 97.07
SOH... 84.09% (still showing 12 capacity bars)
Hx... 82.58%
SOC... 99.2% and 426 GID
403.42v cells balanced between 4.201 and 4.203v
odo... 90,259
43 QC / 2401 L2’s

just noticed this post..

SOH - 84%
Capacity bars - still 12 showing on the dash?
So at what SOH do we lose a capacity bar on the LEAF 40?
Popular mythology is that LEAF 40 capacity bars are set to the same levels as LEAF 24/30, but clearly this is not the case!
Thanks

 

[cwerdna]

just noticed this post..

SOH - 84%
Capacity bars - still 12 showing on the dash?
So at what SOH do we lose a capacity bar on the LEAF 40?
Popular mythology is that LEAF 40 capacity bars are set to the same levels as LEAF 24/30, but clearly this is not the case!
Thanks

It wasn't even clear on 24 kWh Leafs when/what exactly (in terms of criteria) caused a bar to drop. I posted my 1st bar loss (24 kWh Leaf) at https://mynissanleaf.com/threads/2013-2014-bar-losers-and-capacity-losses.18269/page-14#post-511915 when SOH was 83%. At the time, IIRC, Leaf Spy only showed whole numbers for SOH, so I don't know what was past the decimal point.

About the best you can do it compare notes with others to see when there's dropped. It didn't seem to be something instantaneous once SOH reached a certain value. It may need to remain below some threshold for awhile.

 

[RPaulThomas]

just noticed this post..

SOH - 84%
Capacity bars - still 12 showing on the dash?
So at what SOH do we lose a capacity bar on the LEAF 40?
Popular mythology is that LEAF 40 capacity bars are set to the same levels as LEAF 24/30, but clearly this is not the case!
Thanks

Run a search in the forum, there is another thread with a good summary.