openinverter forum

I'm building a 62 kWh battery pack using CATL modules, each with a capacity of 180 Ah, a voltage of 14.8V, a weight of 11.9 kg, and configured in a 4S arrangement. I'm currently using a Nissan Leaf BMS, which I believe is rated for around 40 kWh; it has three temperature sensors, one black high-voltage header, and one grey low-voltage header. To read data from the BMS, I'm using Leaf Spy along with a Bluetooth OBD2 scanner. My plan is to separate the battery pack into two boxes: one with 8 modules in the front and another with 16 modules in the rear.

What have so far achieved
I've successfully connected the BMS to the OBD2 scanner, but Leaf Spy isn’t displaying any data. I suspect this is because l have not yet connected modules

As a newbie, I’ve done most of my research online, and I would greatly appreciate any guidance, suggestions, or advice on how to proceed. Thank you!

Maybe this helps: https://openinverter.org/wiki/Nissan_Leaf_BMS

You will find the 40 kWh BMS is confused with higher capacity cells, i.e. the state of charge will be off.

Maybe this is interesting for you: https://openinverter.org/wiki/16-cell_BMS

Thank you Johu

l want to start with Nissan leaf bms then later may be l will upgrade to 16-cell_BMS

I've successfully connected the BMS, and it shows all 96 cells, with the three temperature sensors working. However, I noticed that in all the YouTube videos I've watched, Leaf Spy displays red and blue lines for the cells, but mine only shows blue. Is the BMS functioning correctly, or am I missing something?

Also, for the BMS gray connector, I used the ground, ignition, charge, and sensor wires, but I didn’t connect the two interlock wires. What exactly do the interlock wires do, and will their absence affect the BMS operation?

My understanding is the red lines in leafspy are cells that are balancing. These typically flash / jump from screen refresh to screen refresh. I usually see it when charging.

If you're never seeing it, I wonder if your battery is in a storage mode..

jrbe wrote: ↑Sun Nov 10, 2024 7:45 pm My understanding is the red lines in leafspy are cells that are balancing. These typically flash / jump from screen refresh to screen refresh. I usually see it when charging.

If you're never seeing it, I wonder if your battery is in a storage mode..

yes these blue lines also flash / jump from screen refresh to screen refresh and even the mV keeps on changing

When Chinese companies sell their CATL modules to Leaf owners, they include a CANbridge to make the different capacity work with what the car is expecting. Some also reprogram the BMS. If this isn’t something you’ve looked into, it is worth exploring.

Also today, Dala released a new video related to this which you should watch. It will lead you on to another forum where some R+D is ongoing.

ianlighting wrote: ↑Tue Dec 03, 2024 5:49 pm When Chinese companies sell their CATL modules to Leaf owners, they include a CANbridge to make the different capacity work with what the car is expecting. Some also reprogram the BMS. If this isn’t something you’ve looked into, it is worth exploring.

Also today, Dala released a new video related to this which you should watch. It will lead you on to another forum where some R+D is ongoing.

Thank you for sharing . I got a CAN bridge and soon l will be installing it

maiks wrote: ↑Wed Jan 29, 2025 8:44 pm Thank you for sharing . I got a CAN bridge and soon l will be installing it

I hope it works for you. I was quite taken by the idea of those CATL modules you see advertised, but I’ve been seeing strong words of caution from some experts. I’m sharing this, not to undermine your choice as I can’t say for sure if it is relevant to you, but to help anyone else who may be considering this approach.

This is a useful thread, esp comments from Dala

https://mynissanleaf.com/threads/shenzh ... ost-656983

maiks wrote: ↑Wed Jan 29, 2025 8:44 pm Thank you for sharing . I got a CAN bridge and soon l will be installing it

But why? There no need for can bridges anymore as we can reprogram the leaf bms

Bratitude wrote: ↑Thu Jan 30, 2025 12:32 am But why? There no need for can bridges anymore as we can reprogram the leaf bms

I kindly request for details on how to reprogram it

maiks wrote: ↑Fri Jan 31, 2025 5:59 pm I kindly request for details on how to reprogram it

dont be lazy. quick search gives you all the info you need.

Bratitude wrote: ↑Fri Jan 31, 2025 6:40 pm dont be lazy. quick search gives you all the info you need.

hahaha .Thank u

Bratitude wrote: ↑Thu Jan 30, 2025 12:32 am But why? There no need for can bridges anymore as we can reprogram the leaf bms

"I’ve tried Dala's process and here’s what I’ve found:

It can only reset the SOH, but it doesn’t reset the SOC. Specifically, you cannot upgrade a 24kWh BMS to a 64kWh BMS, which is necessary for accurate SOC readings.

Additionally, the method of using a CAN bridge from a Chinese CATL battery supply doesn’t seem to work. I connected the CAN bridge between the BMS and the OBD2 reader, but it shows a CAN error in LeafSpy. When disconnected, it works fine.

Any guidance on how to upgrade my 24kWh or 30kWh Leaf BMS to a 64kWh BMS using a CATL battery, so I can get accurate SOC readings SOC

maiks wrote: ↑Tue Feb 18, 2025 10:52 pm

Any guidance on how to upgrade my 24kWh or 30kWh Leaf BMS to a 64kWh BMS using a CATL battery, so I can get accurate SOC readings SOC

https://mynissanleaf.com/threads/revers ... 27/page-20