New 40 kWh pack as replacement for 24 kWh pack

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tcherniaev

Well-known member
Joined
Feb 18, 2012
Messages
82
Location
Salt Lake City, Utah
Hi guys, I know that this video is in Russian, but worth looking at for those who can understand what he is saying: https://youtu.be/t2QdPbgbSdA

For the rest of you, here is a summary:

-- This guy previously swapped 30 kWh pack into a 24 kWh LEAF. It did not work initially, but after he also swapped control modules it worked fine and reported correct capacity, estimated range, etc.

-- 40 kWh battery can't be used as a direct replacement, but he believes that modules can be swapped. Physical dimensions are the same, but some wiring, connections, and control units are not compatible.

-- Internal module design is different, offering a tighter fit, see his prior video: https://youtu.be/r6JeVZbNi6Y

-- His plan is to purchase a salvage 40 kWh pack and do a demo where he actually upgrades an old LEAF to 40 kWh.

As a side note, here is a video from Ukraine Tesla guru who visits LEAF aftermarket shop where they dismantle LEAF battery packs, test each module, and reuse those modules that are still good. What is interesting about this video is that they highlight that, in a typical battery, heat damage to the modules in the middle is much worse that damage to perimeter modules. They link it to a lack of thermal management in LEAFs (I know, big surprise). https://youtu.be/SVTtXvGmBvU
 
Hi!
I watched this video. I can translate, what interests you ?
I am interested in questions of increase in a charge of batteries too. :D
 
I would be interested in any information about what batteries I can eventually swap into my 2013 Leaf when the current 24 kWh battery degrades to the point where it's no longer usable.

So any translations that help with that would be most appreciated.
 
Silverfish said:
I would be interested in any information about what batteries I can eventually swap into my 2013 Leaf when the current 24 kWh battery degrades to the point where it's no longer usable.

So any translations that help with that would be most appreciated.

I understand your question.
You can install 30 and 40 KW battery cells without significant rework.
You will need to reprogram the controller so that the car understands the actual range of distance.
I can recommend a YouTube channel where such issues are dealt with https://www.youtube.com/TehnoVinTar
The author speaks Ukrainian, but knows English well and can answer your comments.
 
ybpvin said:
Silverfish said:
I would be interested in any information about what batteries I can eventually swap into my 2013 Leaf when the current 24 kWh battery degrades to the point where it's no longer usable.

So any translations that help with that would be most appreciated.

I understand your question.
You can install 30 and 40 KW battery cells without significant rework.
You will need to reprogram the controller so that the car understands the actual range of distance.
I can recommend a YouTube channel where such issues are dealt with https://www.youtube.com/TehnoVinTar
The author speaks Ukrainian, but knows English well and can answer your comments.

Thanks!
 
ybpvin said:
You will need to reprogram the controller so that the car understands the actual range of distance.

Any idea how that would be done? Any links to where this is discussed? The difference in discharge curves for 30 and 40kwh packs is the real problem with regards to swapping cells.
 
Lothsahn said:
ybpvin said:
You will need to reprogram the controller so that the car understands the actual range of distance.

Any idea how that would be done? Any links to where this is discussed? The difference in discharge curves for 30 and 40kwh packs is the real problem with regards to swapping cells.



Hello.
This question is difficult and did not meet on the forums.
Here is the author's latest video where the battery issue is discussed. https://www.youtube.com/watch?v=sWmiOxl0pdg&t=3s
Write a comment in English and he will answer you.
 
Hello Friends,

Did any of you received an answer, how to change the capacity value in the LBC (battery controller)?

Thanks in advance for your help!
 
LeftieBiker said:
What about using a 30kwh pack controller with a 40kwh pack, and just considering the extra 10kwh that the controller can't "see" as a buffer?

There is cell voltage control in the LBC, and the 40 and the 30 kWh packs have the same voltage references at module level, so it should work. The range estimate is the question, if the system will adopt to the higher capacity or not. The best would be to change the value in LBC from 30 to 40, but how to do this is the real question.
 
There is cell voltage control in the LBC, and the 40 and the 30 kWh packs have the same voltage references at module level, so it should work. The range estimate is the question, if the system will adopt to the higher capacity or not.

The range estimator can already come up with some pretty high estimates at times, based on low consumption over a given distance and/or time. If it "sees" that the pack voltage is only dropping very slowly over X distance in Y time, shouldn't it adjust the range estimate higher without even having to "know" that the pack has more capacity?
 
Testing is necessary, to understand, how the 30kwh controller adopts. I’m also curious about the quick charging performance, as the 30kwh software would manage the charging of the 40kWh modules. If any overheating happens, probably it would reduce the current, just as it is done in the 30kwh edition.
 
bkvszomorito said:
Testing is necessary, to understand, how the 30kwh controller adopts. I’m also curious about the quick charging performance, as the 30kwh software would manage the charging of the 40kWh modules. If any overheating happens, probably it would reduce the current, just as it is done in the 30kwh edition.

Another thing to consider and worry about is the discharge rate. While I would expect the inverter to limit the maximum current, if the 40kWh has significantly less internal resistance, it *could* theoretically generate more current than the 30 kWh packs, resulting in a higher current. We DO know that Nissan upgraded the internal fuse in the battery pack with the 40 kWh pack, so there's a possibility you could either blow the HV fuse or damage components if the current draw was significantly higher.

I suspect the fuse upgrade was really because they increased the motor HP in the 2018 Leaf, not the battery, but there's a small risk...
 
Lothsahn said:
bkvszomorito said:
Testing is necessary, to understand, how the 30kwh controller adopts. I’m also curious about the quick charging performance, as the 30kwh software would manage the charging of the 40kWh modules. If any overheating happens, probably it would reduce the current, just as it is done in the 30kwh edition.

Another thing to consider and worry about is the discharge rate. While I would expect the inverter to limit the maximum current, if the 40kWh has significantly less internal resistance, it *could* theoretically generate more current than the 30 kWh packs, resulting in a higher current. We DO know that Nissan upgraded the internal fuse in the battery pack with the 40 kWh pack, so there's a possibility you could either blow the HV fuse or damage components if the current draw was significantly higher.

I suspect the fuse upgrade was really because they increased the motor HP in the 2018 Leaf, not the battery, but there's a small risk...

Calm down.. .. " While I would expect the inverter to limit the maximum current," It will, so that will not be a problem. You are keeping the original fuse if you are worried. It may take a bit longer to quick charge because the battery is bigger and the current values in the software are for a smaller battery. Big deal. I wish I had a quick charger within range of my car.
 
bkvszomorito said:
There is cell voltage control in the LBC, and the 40 and the 30 kWh packs have the same voltage references at module level, so it should work. The range estimate is the question, if the system will adopt to the higher capacity or not. The best would be to change the value in LBC from 30 to 40, but how to do this is the real question.

According to mux, it doesn't adapt to a larger pack for range estimation. He has actually started a company in Norway that has begun the first round of installing range extender packs in LEAFs. Lots of good info on his YouTube channel:

https://www.youtube.com/user/PowerElectronicsBlog?app=desktop

https://muxsan.com

He seems to have solved the range estimation issue by installing a CANBUS brisge as a "man in the middle", which can intercept and modify CANBUS communications. Tying that into the BMS for the extender pack too, the VCM thinks it has a 40 kWh pack, which it basically does.

Perhaps his company would sell the CANBUS bridge, worth asking...

Ideally, they license all the goodness they've created, so that shops in North America can start offering and installing extender packs here.
 
I am very much looking forward to this.

My 88% SOH 24kwh battery just doesn't pack quite enough power to do what I want in the coldest part of winter. And that's me driving around with the heat off, no fun.
 
My car has 30kWh pack, with 40kWh pack modules. Those modules are from scrapyard, from a vehicle with very low mileage, and perfect SOH. Currently I can drive only 220km with the pack, and it can store approximately 27kWh according to LEAFSpy. This seems to mean, that the 30kWh BMS is limiting the capacity. The pack voltage is 332V around 0% SOC (turtle mode on), and it is 397V when the pack is fully charged. The strange thing is, that the SOH value according to LEAFSpy is 90%, and the Hx is 74%. This means, that the chemistry and the internal resistance is different in case of the 30 and the 40kWh modules.

Do you have any idea, how to get the full capacity of the 40kWh modules? The 40kWh BMS is not compatible with the VCM of the 30kWh car, so it cannot be mounted directly. With this setup, the real SOH (not the calculated one by 30kWh BMS) of the 40kWh should last quite "forever", but it would be nice, to have more range out of the pack.

As I saw, the 40kWh pack with the original BMS should be around 405V with 100% SOC, so there might be the "missing" capacity, but the 30kWh BMS is limiting the voltage around 397Volts, so charging further is not possible.

Any help, to find a solution is appreciated!
 
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