Hi everyone,
I’m finishing a new installation and have run into a communication problem that I can’t solve. I’d appreciate some advice from anyone who has successfully connected a JK BMS to Victron.
System setup:
• Inverter/charger: Victron MultiPlus II 48/15000/200-100 (firmware v558)
• ESS managed by Ekrano GX (new Cerbo GX model)
• PV:
– 2 × Fronius inverters (AC-coupled)
– 1 × SmartSolar MPPT 250/85 (DC-coupled)
• Batteries:
– 4 × LiFePO₄ JK-PB2A16S20P v19 (314 Ah each) — currently testing with only one connected
– Interconnected via Lynx Power In + Lynx Shunt + Lynx Distributor
– 250 A fuses per battery, 400 A main fuse
Goal:
I need the Ekrano GX to detect the JK batteries over CAN-bus, without using any external battery monitor.
Current setup:
• Custom RJ45–RJ45 cable from VE.Can (Ekrano GX) to CAN port (JK BMS)
• BMS protocol: 004 – Victron_CANbus_BMS_protocol_20170717
• Baud rate: 500 kbps
• Tried both pin orders (CAN-H / CAN-L swapped)
• 120 Ω terminators at both ends
• RS485 communication between batteries works fine
• GX still shows “No BMS detected”
• Victron keeps SOC fixed at 100 %, while the BMS reports ~25 %
• Ekrano GX does not recognize the CAN device
I’ve been testing for several days and can’t get the GX to detect the JK BMS.
If anyone has managed to make this setup work or has the correct CAN pinout/protocol combination, I’d really appreciate your help
I’m glad you asked. I have a very similar project coming up and I suspect I will have similar problems.
It would be interesting to know which JK-BMS firmware you have on the JK-BMS. Andy /Off-Grid Garage has had very different results with the new version 19.
Thanks a lot for your reply!
Yes, I’ve seen Andy’s videos too — that’s partly why I expected it to work .
I’m currently using the JK-PB2A16S20P v19 firmware, and I suspect that’s exactly where the issue might be.
I’ll double-check the firmware behavior and CAN protocol settings again in the next few days.
Honestly, I’m starting to get a bit desperate because everything else in the system works perfectly — just this communication won’t come alive.
Yes, I just saw that — thanks for pointing it out!
I’ll look for the latest firmware mentioned in Andy’s post and try updating the JK-BMS to see if that improves the CAN communication.
Let’s see if one of those new protocol updates in v19.13 finally makes it work with Victron. Thank
Yes, I saw that — thanks for sharing!
I actually already have the latest firmware (v19.10) installed on my JK-BMS, so it should include those new communication protocol updates.
Still, the Ekrano GX doesn’t detect it over CAN, so maybe something in the new firmware changed the protocol behavior.
On mine cerbo gx the JK BMS works fine.
You need type B cable, between cerbo GX BMS CAN and first battery CAN connector.
Victron BMS CAN speed 500k
Jumpers first JK BMS must be all zero!!!
In JK BMS set can protocol No: 4
Last couple of days I have been strugling as well. My system is also the multiplus II with two 100A JK inverter BMS’s V19 and the Cerbo GX MK1.
But have it running since yesterday, but with the type A cable, which I’m pretty sure is also the cable that Andy uses. Cable goes from BMS-can port to the 2 of 4 RJ45 ports.
I’ve read more that it would also work with the type B cable.
Eureka — it’s finally working with the Type B cable!
The Ekrano GX immediately detected the JK-BMS and started reading all values correctly.
Thanks a lot to everyone here for the help and guidance — really appreciate it!
The jumpers are the red part and should be all off (0000) for first battery (with CAN cable).
The second cable go’s to the second battery pack (RS485-2 → RS485-2 port and jumper setting 0001), third pack with 0010,0011,…
This way from all battery pack cells the voltages and temperatures are monitored over CAN.
.
