Nissan Leaf BMS

[janosch]

I changed only batteries, not BMS or other parts in battery box.

It sounds like you did a 40kWh upgrade? Surprised the 40kWh cells fit into the 24kWh box without changes.

Best forum member to talk to is dala https://dalasevrepair.fi/

I think you will need:

• 40kWh BMS
• dalas 40 -> 24 CAN bridge

and with that fitted the Leaf should understand the bigger battery.

[Jacobsmess]

Ok, so anyone got a TLDR; for how to use the leaf BMS from a 40kWh pack? One arrived today, I suspect I'm going to have to do some digging. I've read a lot so far but nothing super conclusive for my tired brain.

Can I just hook up 12V, Gnd, CanH and CanL and get data via a Bluetooth dongle and leafspy lite? Is there some documentation on which cells connect where on the BMS cabling?

Thanks

[Jacobsmess]

I 've attached the wiring diagram from the 2013 BMS that I used in my car.

Ok so this is a great start for wiring things up, although interestingly my LS11 connector has an extra wire that's not shown on this diagram on pin 11.

[Jacobsmess]

The BMS cannot limit anything, it only measures voltage and current and it will balance the cells 24/7 as long as it receives +12V on pin 5 (BAT) of the round connector, which is wired to pin 12 of the LB11 connector.
Also, all 96 pairs of cells need to be plugged in obviously.
The BMS will only communicate when there is 12V on either IGN (pin 4 round connector, pin 6 or 7 of LB11, for old/new BMS) or CHG IGN (Charging) which is located on pin 21 or 31 (old/new battery type), pin 5 of LB11.

Source: https://www.diyelectriccar.com/threads/ ... ost-871641