openinverter forum

Hey guys, I've been working on an EV conversion for my BMW E30, and around two years ago I bought a 62kwh Leaf pack. I'm now ready to put this pack in my car with an LDU (controlled w Open Inverter), and I've been looking at BMS options to do so. From what I understand, the two Leaf BMS's that manage packs below a 62kwh capacity have been successfully used in conversions for a while. The most in-depth solution I've come across for this is Isaac's Boxster. However I'm not sure if solution is compatible with my pack. While I've found some people who believe the CAN data will be packaged differently due to the different cell count, I would think the BMS would treat the cells that are in parallel as one cell, rather than each actual individual cell. "The 62kwh style has 16 complete modules. 4 Large(9 cell), 4 Medium(7 cell), 8 small(4 cell). Each "cell" is actually 3 cells, but they are in parallel so we treat them as 1." Essentially what I'm asking is this: Can I plug and play the already available Leaf BMS solutions for my pack, or do I have to accomplish some level of software reconfiguration (which I wouldn't even begin to know where to start)?

If using the Leaf BMS isn't feasible, what BMS options for this pack do you guys recommend? At least I can rest easy at night knowing I can always throw money at the problem and buy an Orion2.

It's still a 96S pack so the CAN format wouldn't necessarily differ. I know for sure that the 24, 30 and 40 KWh BMSes are identical CAN-wise

An open source alternative is going to be this one viewtopic.php?t=2338 among a few others

I had a Leaf BMS up and running by just applying 12V. You can monitor it using Leafspy if you have the CAN leads going out to a suitable ODB2 port.
I had it connected to my eGolf batteries so I suspect balancing will be minimal but I could monitor all cell voltages.

Alibro wrote: ↑Tue May 30, 2023 2:09 pm if you have the CAN leads going out to a suitable ODB2 port.

Do you mind sharing how you wired the CAN leads to an OBD2 port?

It would be interesting to know if the pinout and connectors are still the same, I made a test board for that a while ago. Most likely it will be identical but you never know:
viewtopic.php?t=2085

Got any photos of the BMS?

janosch wrote: ↑Tue May 30, 2023 8:16 pm Got any photos of the BMS?

2020 Nissan Leaf 62kwh BMS pictures

ekohn04 wrote: ↑Tue May 30, 2023 4:47 pm Do you mind sharing how you wired the CAN leads to an OBD2 port?

TBH I can't remember exactly how but basically just connected the CAN wires from the OBD2 port (removed from the Leaf) to the CAN wires from the BMS.
There are two CAN busses at the OBD2 port and I think I just joined them because I wasn't sure which one was picked up by the bluetooth adapter then ran the CAN cables from the battery pack connector to both connections.
I used the original battery pack harness to connect the BMS.
This is a video I put out last year and most is now redundant or irrelevant for you but near the end I talk about getting LeafSpy working.
Hopefully some of it might help.

There is a setting in Leafspy to change operation from full car to BMS only so make sure you change that.