Standalone testing Nissan Leaf 40kWh battery

[ruffieuxh]

Hi,

I am an engineer with a car background and some 10 years experience in EV driving but new to technical BMS details.
Now I want to install a used Nissan Leaf 40kWh 2018 pack as a battery backup for my PV installation based on this work from Dala: https://github.com/dalathegreat/BYD-Bat ... -For-Gen24

I just received the pack with zero physical damage and now would like to test the interior to provide feedback to the seller. If possible I would not like to open it. The seller showed me in a video, that the battery was working and was in good condition when it was still installed in the car.

After having wired up all the required connections, I attached an old ATX Computer power supply for the 12V as well as a Bluetooth ODB2 dongle with LeafSpy Pro. The connection to the dongle works, but I cannot get the CAN to working (CAN Bus error) and I am not even sure if the BMS itself is live.
I checked the wiring including the one to the ODB2 connector already 3 times.

Is there anybody who could help me with some hints here?

The wiring diagramm:

My first questions:

• Does the emergency disconnector need to be in to test BMS? Not according to what I see on the wiring diagram.

• Same question for the 3 Relais (Pre Charge, Main Rly 1 and 2

• I have PIN 4 (IGN) and PIN 5 (BAT) on constant 12 V. How about PIN 31 (CHG IGN)? Does this one only need 12V when charging?

Is there any other hint you can give me? I had the impression, that it should be pretty simple to bring the BMS to life. But it is giving me a hard time...

Thanks a lot

Heinz

[ruffieuxh]

Nissan Leaf Spy looks as follows and Car Scanner app says, that I have a connection to ELM but not to the ECU.

[ruffieuxh]

I may have found the problem. It looks to me, that the 36pin plug is labeled the wrong way (mirrored)!

I totally missed the "H.S." symbol. As far as I can see (from the pins in the male connector at the battery), this is the pinout of the terminal at the battery not from the plug:

Bildschirmfoto vom 2023-08-12 16-44-28.png (14.35 KiB) Viewed 9609 times

The 3 positioning pins lead me to the conclusion, that it must be the view from the terminal side and not from the cabling side.


But the plug at the back is labled exactly mirrored, Pin 1 being upper left, which basically is correct if you turn it around and compare it with the layout above! Ist that normal? Am I wrong?

Bildschirmfoto vom 2023-08-12 16-50-00.png (281.7 KiB) Viewed 9609 times

I hope, I did not fry anything by that....

[ruffieuxh]

Works now! After I mirrored the cables, it worked instantly. Fortunately nothing seems damaged!

[anthonyevs]

Hello Heinz,
I am having the same issues you had when trying to connect to my stand alone battery,
can you please advise where exactly you connected onto the pins to get the leafspy to connect to the bms.
I have a cable ready to connect, i have tried connecting as follows
looking at the pins sticking out of the plug on the battery
from the tech drawing with pin 1 top right, i connected my canh canl to pins 1&2
connected +12v live to pins 4 and 5
connected neg to pins 6, 7 & 8
Get no connection this way.

so do you do this
connect canh to pin 5 canl to pin 4
+12v to pin 1 & 2
neg to pins 12, 11 and 10

is this the correct way?

Thank you
Anthony

[ruffieuxh]

Hi Anthony,

I think your current pinout is correct (from a pin number perspective). The numbering in the picture of my first post is correct but mirrored.

I found that out by checking on which side the block of 3 pins is on the connector side. Pin 1 is the outer side of the 3 pins block of the first row!

If you watch my cabling photo you see, that the CAN pins are on the left, while the pinout diagram show pin 1 and 2 on the right side.

I hope, this is not too confusing

Best regards

Heinz

[anthonyevs]

Hi Heinz,
thank you for replying.

today i tried getting leafspy to connect, but had no connection.

looking at the back of the plug, i connected
pin 1 can h
pin 2 can L
pin 3 +12v
pin 4 +12v
pins 5,6 & 7 GND, although on the socket on the battery there is no pin at pin 5 present, there are only pins present at pin 6 and 7

With this connected on a 12v lab power suppyly, the leafspy dongle powers up ok by get a can error message.

I fear there is something wrong with the bms, perhaps i destroyed it by putting 12v onto the canh and canl pins yesterday.

Anything else I could try?

Thanks
Anthony.

[ruffieuxh]

Hi Anthony,

Well, looks correct to me. Just to be sure: You are looking at the back of the plug like the photo in my 3rd post? If your CANH is then at the top left, you got it right. I also connected it wrongly the first time and nothing happened to the BMS.

Did you make sure that the pins are REALLY all fully inserted? It happened to me more than once, that some of the pins came out during inserting the plug, so you may want to check them AFTER you plugged in.

I got most of the information for me at this wiki page: https://github.com/dalathegreat/Battery ... AF-battery

I do not know what year your battery is from, but please note, that pre-2013 batteries have a different pinout (see wiki page above)

Other than that I'm afraid that I'm out of ideas what else to try. Maybe you can measure resistance on the CAN bus to check, if it is still ok. But I do not know what values must be there.

Best regards

Heinz