How to Connect a JK Inverter BMS to Victron
Victron + JK inverter BMS guide
How to connect a JK Inverter BMS to a Victron GX system
This guide is for JK PB-series / JK Inverter BMS models with CAN communication, connected to a Victron GX device such as a Cerbo GX, Ekrano GX, Venus GX, or Venus OS system.
Best connection
Use CAN from the JK inverter BMS to the Victron GX device. This is the cleanest setup for a managed lithium battery because the GX device can receive charge and discharge limits from the BMS.
Main thing to avoid
Do not assume a normal Ethernet cable is correct. The RJ45 connectors look familiar, but the CAN pinout is not standard Ethernet.
Exact model matters
JK hardware revisions and app labels can differ. Always verify the CAN port, cable pinout, and protocol setting for the exact BMS you are installing.
What this connection actually does
When the JK BMS is communicating properly over CAN, the Victron GX device can see the battery as a managed lithium battery. With DVCC enabled, the GX device can use BMS-provided limits such as charge voltage limit, charge current limit, and discharge current limit.
In practical terms, this lets the BMS tell Victron equipment when to charge harder, slow down, or stop. It is a better approach than relying only on fixed charge voltages inside the inverter or MPPT.
Recommended wiring approach
For current JK inverter BMS setups, the usual recommendation is a Victron VE.Can to CAN-bus BMS Type B cable, Victron part number ASS030720018. Some users report that Type A can work because CAN-H and CAN-L are the same and the ground is less critical, but Type B is the cleaner starting point for JK inverter BMS.
| Function | Victron GX side | JK inverter BMS side | Notes |
|---|---|---|---|
| CAN-H | Pin 7 | Pin 4 | CAN high signal. |
| CAN-L | Pin 8 | Pin 5 | CAN low signal. |
| GND | Pin 3 | Usually pin 2 for Type B | Some JK documents/variants show different ground references. Verify before crimping. |
Step-by-step setup
Confirm the correct JK port
Use the JK BMS CAN port, not the RS485 port. On some JK documentation or hardware revisions, labels and port order have caused confusion, so check the manual and look for CAN traffic if the GX does not detect the battery.
Connect the CAN cable
Connect the JK CAN port to the Victron GX CAN port intended for managed batteries. On older Cerbo GX units, this is commonly the fixed BMS-Can port. On newer GX devices, the VE.Can ports may be configurable.
Set the JK protocol
Open the JK app, enter settings, and set the inverter/CAN protocol to the Victron CAN protocol. On many JK PB models this is shown as Victron or protocol number 4. Restart the BMS after changing protocol.
Watch the JK app protocol setting walkthrough here without leaving this guide.
Configure the Victron CAN port
On the GX device, go to the CAN port settings and set the relevant port to a BMS/CAN profile at 500 kbit/s where applicable. Older Cerbo GX BMS-Can ports are fixed at 500 kbit/s.
Check the GX device list
Return to the device list. If communication is working, the battery should appear as a connected BMS/battery device. Check that voltage, current, SOC, and limits look sensible.
Enable DVCC
Enable DVCC/Charge Control on the GX device so Victron chargers and inverter/chargers can follow BMS-provided limits. Confirm charge voltage limit, charge current limit, and discharge current limit are being received.
DVCC settings to check
With a managed CAN-bus battery, the key is not to manually force charge voltages everywhere. The BMS should be sending limits and the Victron system should be following them.
- DVCC / Charge Control enabled.
- Battery appears in the GX device list.
- CVL, CCL and DCL values look realistic.
- Charge current limits are not higher than the battery, wiring or BMS can safely support.
- Any manual voltage limiting is intentional and understood.
Troubleshooting
The BMS is not showing up on the Victron GX device
- Confirm you are plugged into the JK CAN port, not RS485.
- Confirm the JK protocol is set to Victron CAN / protocol 4 where applicable.
- Confirm the GX CAN port is set for the correct BMS/CAN profile and speed.
- Try a known-good Type B cable or continuity-test your custom cable.
- Check termination on the CAN bus.
The battery appears but charge control does not seem right
Check that DVCC is enabled and that the GX device is receiving CVL, CCL and DCL from the battery. Also check whether any manual charge voltage/current limits are overriding or reducing what you expect.
I have multiple JK batteries in parallel
Normally one master BMS communicates with the Victron GX device, while the JK batteries communicate with each other using the JK parallel/RS485 arrangement. Addressing must be set correctly. Follow the JK manual for your exact model.
Can I use RS485 or Bluetooth instead?
For a serious 48V Victron power system, wired CAN is the preferred path when the JK inverter BMS supports it. RS485 or third-party Venus OS drivers can be useful for some older/non-inverter BMS models, but they are not the cleanest first choice for a managed battery system.
Useful references
Need help choosing the right JK, Victron or LiFePO4 battery setup?
If you are building a 48V battery system and want it to communicate properly with Victron, it is worth checking the BMS model, battery design and cable choice before ordering parts.
Contact LIFEPO4 Australia