Standalone testing Nissan Leaf 40kWh battery

Topics concerning OEM and open source BMSes
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ruffieuxh
Posts: 4
Joined: Sat Aug 12, 2023 12:15 pm

Standalone testing Nissan Leaf 40kWh battery

Post by 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:
Bildschirmfoto vom 2023-08-12 14-26-48.png
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
Posts: 4
Joined: Sat Aug 12, 2023 12:15 pm

Re: Standalone testing Nissan Leaf 40kWh battery

Post by ruffieuxh »

Nissan Leaf Spy looks as follows and Car Scanner app says, that I have a connection to ELM but not to the ECU.
Screenshot_20230812_153927_LeafSpy Pro.jpg
ruffieuxh
Posts: 4
Joined: Sat Aug 12, 2023 12:15 pm

Re: Standalone testing Nissan Leaf 40kWh battery

Post by 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
Bildschirmfoto vom 2023-08-12 16-44-28.png (14.35 KiB) Viewed 3111 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
Bildschirmfoto vom 2023-08-12 16-50-00.png (281.7 KiB) Viewed 3111 times
I hope, I did not fry anything by that....:-(
ruffieuxh
Posts: 4
Joined: Sat Aug 12, 2023 12:15 pm

Re: Standalone testing Nissan Leaf 40kWh battery

Post by ruffieuxh »

Works now! After I mirrored the cables, it worked instantly. Fortunately nothing seems damaged!
Screenshot_20230813_172117_LeafSpy Pro.jpg
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