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Nissan Leaf BMS wiring differences between 2013 24kWh vs 2018 40kWh

3817 Views 18 Replies 8 Participants Last post by  hfraza
I'm trying to find out if the wiring, connectors, and pinouts between the 2013 and 2018 BMS to battery modules are different or the same. I haven't found any pin diagrams for to the BMS anywhere so if anyone has a source I'd be happy to know.

For context, I'm planning to replace the 2013 24kw modules with 40kw modules. From what I understand this method is call a bruteforce upgrade. There shouldn't be any controller issue as I'm using the Resolve-EV controller but my research thus far suggests issues with the BMS not recognizing 40kw thus not reporting the correct capacity not being able to charge it fully.

So this means I'll be also upgrading the BMS from 2013 to 2018 but that leaves open a question whether the wiring has changed or not. From a glance, the connectors look the same but the pin out on the connectors is unknown.

If anyone has a 40kwh battery and has a pin map for the connectors, that should help.

In case someone comes across this thread again, I documented my solution here:
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try to look into this recently published wiring schema for latest Leaf (ze1). Probably do not have the battery internal wiring schema and pinout.
Yes, this doesn't have the internal wiring schema between battery controller(BMS) and the modules themselves.
ok, now I just need to compare them and modify as needed.
Go find the posts from dala the great--he has done just this sort of upgrade and has all the knowledge.
From what I was able to Google, Dala calls this method bruteforce and doesn't recommend it. What I figured out from his work is this upgrade has many issues when used to upgrade a Leaf itself as the BMS and ECU won't recognize each other due to different IDs. I saw and read he used a man in the middle to "patch" the I'd which allowed him to upgrade his battery. Also what I'm doing is too "troublesome" for leaf owners.

What I took away is BMS needs to be able handle the batteries or else it will not provide the right numbers to the controller. Since my 2013 controller doesn't know the existence of a 40kw battery, upgrading the BMS should fix that. From my analysis, the wiring and connectors are identical between 2013 and 2018 to the BMS. So I should be able to just swap to a newer BMS and use the 40kwH battery with my Resolve-EV controller.
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If only all of these posts and information was available when I ordered my battery modules here in nz. I've put 40kwh modules in my 2013 leaf. It fully charges and discharges it correctly it just can't calculate the correct capacity so it still gets 100 odd kms after the bms thinks it's empty. If I monitor pack voltage on leafspy I can see more or less where the soc is sitting...
You're using the 2013 BMS with 40kwh modules?

If so then your battery likely isn't charging fully according to Dala. Have you measured the actual range you're getting?

In order to charge it fully, you'd need a 2018+ BMS from a Leaf. Like Dala said, it's easier to swap the whole pack instead of bruteforce since it includes BMS, sensors, wiring, etc. But given how difficult it is to buy a 40kwh Leaf battery pack, I personally bought modules too.

With the modified wiring and current sensor like I mentioned in my original post and a 2018 BMS, your battery would be able to charge it fully but you'd have pairing issues with the 2013 ECU which I theorize could be solved with Dala's can-bridge. Since it would allow you to pair your new 2018 BMS with the 2013 ECU, its equivalent to pair a full battery pack (that you bought in piecemeal)

Edit: this might help:
If you use the 40kWh cells with a 24kWh BMS, you will only get 24kWh of energy out/in. You need the entire 40kWh pack, the Resolve-EV controller is actually compatible with all different battery sizes natively. Don't bruteforce it!

The wiring is different for the 2013 and 2018. The current sensor has 4 pins instead of 3 pins. The BMS leads might have changed somethin, we don't have the 40kWh pinout available. Use an entire 40kWh pack (cells+wiring+LBC+currentsensor)
I'd love to not bruteforce it but modules are easier to find than entire battery packs now. You've popularized battery swapping for the leaf and I think one shop in Portland Oregon is buying all the stock in the US. 😅

I got the pinout for 2018 vs 2013 and verified that internally, the BMS wiring is identical except for the current sensor. However the wiring to the junction box is different. So the "easy" route I took was to piecemeal together a 40kwh pack with a combination of 2013 and 2018 parts.

2013 harness, with 2018 current sensor wiring, 2018 four wire current sensor, 2013 junction box, 40kwh modules. The BMS wires to modules are otherwise identical and the 2013 battery harness will work find with both 2018 BMS and 2013 junction box. 2018 harness will not work with a 2013 junction box as those pins are different. Add in your muxsan can bridge and this in theory should work in a leaf!

In short, if my understanding is correct it is possible to piece meal build a 40kwh leaf battery pack and swap it into a leaf. I don't have a leaf to test but you might one day. If you have difficulty finding full battery packs like me and are able to acquire modules, then this solution "might" work.

Edit: apologies, just realized I replied to a super old reply
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Yeah like you say it's hard to get a full 40kwh pack, especially in new zealand. For anyone needing it, there's a company here in nz that sells a battery translator that means you can fit a full 40kwh ze1 battery and it translates the back so Soc and soh are both correct on the dash.

Yeah I replaced all the modules and it fully charges and discharges correctly its just a bit confused on the dash. Charges to 396v and discharges to 290v when turtle mode and cut out happens. I got 220kms and mostly 100-110kmh roads. I know my speedo is 5kms and 5% out so probability closer to 200kms in the real world but close enough.
If you're down to experiment to get your dash reflecting the values right, the BMS and Current sensor are sold on Nissan's website:
Nissan 293A0-5SA2AController Assy-Battery
2018-2019 Nissan Leaf 293A05SA2A
293A0-5SA2A Genuine Nissan #293A05SA2A Controller Assy-Battery offers the great deal for genuine Nissan parts 293A0-5SA2A (293A05SA2A) Controller Assy-Battery for $667.58.

2018 Current Sensor:
Nissan 294G0-5SK0ASensor Assy-Main Current
2018-2019 Nissan Leaf 294G05SK0A
294G0-5SK0A Genuine Nissan #294G05SK0A Sensor Assy-Main Current offers the great deal for genuine Nissan parts 294G0-5SK0A (294G05SK0A) Sensor Assy-Main Current for $139.02.

If you're comfortable with module swapping then I assume you can run the wiring as I described in the other thread:

with that, you've basically built yourself a 40kwh battery pack thus the only thing missing would be the battery translator to pair the "new pack" BMS ID to your ECU. Good luck!
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