I am looking for help to connect my JKBMS to My Victron. It is a new set up and not yet installed, so I ma just testing before I go further.
A bit about my set up: Multiplus 48/4k5 and Cerbo Mk2. My battery is 16.3kwh and the BMS is JK BMS (V19A).
I have tried in many ways to connect the BMS to the Cerbo, but continue to fail making it work.
First I tried with a UTP cable I received with the battery, thinking it was to be connected between the RS485 CAN to the CAN bus on the cerbo. I was initially told that only in the JKBMS I should set the protocol to Pylontech or Victron. That did not work.
Than, based on references that I found, I tried it with a new cable. A RS485 FTDI cable, with RJ45 on the BMS side connected to the RS485-2 port and to the USB port on the Cerbo. Settings on the JKBMS changed to protocol 1 or 13 (modbus) for UART1 and UART3. And that did not work either.
Afterward, In a discussion with Copilot I understand that the Cerbo MK2 does not support serial battery connection, as versions in the MK2 (v3.67) run behind compared to the original Cerbo (which is on version 4+ and would support such serial connections).
Next I have read that the way forward is with dbus software to be found in github, either on a raspberry pi or on the Cerbo MK2, but I have not tried that yet.
In other posts I read that a CAN bus connection should be made with a type-B BMS cable, and than in other posts again seeing comments that that will not work.
Before buying more cables without knowing what would and should work, I hope someone can help me out with advice what to do next.
Caution should be said on connecting jkbms directly, as older jkbms connection ports had full battery voltage on one of the pins and potentially could fry items directly connected to it, unknown to myself if newer versions have this or not.
I use a “ type A” Can cable, I bought one from Victron, in the Cerbo plug it in the VE Can- 1 bus; the adjacent socket you plug in a Victron ‘ terminator’, then set BMS “baudrate” in the Cerbo/ VRM to 500kb/sec, at the battery connect the cable in the rs485-Can socket.. set “ Can Protocol no” to “004 Victron Canbus”
With a cable that I bought from Ali, I could not make it work with the dbus software.
I have set up a pi that I have still have lying around and I could make it work with dbus using bluetooth on the dbus software.
Then, I thought doing the exact same on a Cerbo MK2 and there nothing happens. Is there a problem on the Cerbo for this, situation or could there be I am missing something?
I will look for such a cable and then test again (and will report back here).
I’ll probably get 2 cables, as I have read comments that a cable type A is needed and in other comments that it should be a type B cable.
A very interesting journey to get something working that I would have thought to be a straight forward thing to get in place.
The YouTube videos from “ Off grid garage” have been invaluable to me, particularly this one: “ the new jk inverter bms: all settings, features and functions explained, everything you need to know” (30 jan 2024)… the bms version here is v15 but the settings mostly apply for the v19 version as well, check his videos for the v19 version.
Be sure the battery bms is set as battery monitor in the Cerbo/ vrm.
I have a different Victron inverter, I can’t help you with the settings of your Multi plus inverter.
