Victron Multi RS 48/6000 + JK BMS CAN Communication

Forum discussions and user experiences regarding the integration of the JK-PB2A16S20P BMS with the Victron Multi RS Solar 48/6000.

Here we have tried to compile as much information as possible in regards to the JK BMS and Victron RS Solar 48/6000 All in One Inverter and communication with a lifepo4 battery. This topic requires the use of an external Cerbo GX, because the Multi RS Solar cannot communicate at the correct baud rate. Read on to see all the details

Integrating a JK BMS specifically the JK-PB2A16S20P BMS with a Victron Multi RS 48/6000

Overview: The JK-PB2A16S20P (a 16-cell, 48V “inverter” JK-BMS with CAN) can be integrated with a Victron Multi RS Solar 48/6000 inverter-charger. Users on various forums have shared their experiences getting these devices to communicate via CAN bus. Key steps include proper wiring (using Victron CAN cables), matching CAN-bus speeds, setting the JK BMS to the correct protocol for Victron, and configuring the Victron GX device (e.g. Cerbo GX) with DVCC so the BMS can control charging. Below are highlights from user discussions, including successful setups, required settings, and common issues encountered.

Connection and CAN Bus Compatibility

Victron GX Configuration (Cerbo GX / DVCC Settings)

Most integrations use a GX device (such as Cerbo GX or Venus OS on a Raspberry Pi) to interface the BMS with the Multi RS inverter:

  • Enabling DVCC: Victron’s Distributed Voltage & Current Control (DVCC) must be enabled for the inverter/charger to actually obey external BMS commands. Simply seeing the BMS data on the Cerbo GX is not enough; DVCC allows the BMS to actively limit charging. In one case, a user’s Multi RS was “stuck in Discharging” and not using solar, until it was noted that the system was not under BMS control (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community). Once DVCC was enabled on the Cerbo and the battery was properly detected, the Multi RS transitioned to using the BMS info for charge regulation. On the GX device, under Settings → DVCC, “Allow battery to manage chargers” should be on, and the JK BMS will be listed as the controlled battery. A user noted their DVCC menu showed “Used sensor: JK-BMS on CAN-bus,” indicating the system had picked up the JK BMS as the battery monitor (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community). With DVCC on, the Multi RS display should indicate “External control” for charging, meaning it’s listening to the BMS.
  • Battery Monitor Selection: In some cases, after connecting the JK BMS, the Cerbo GX might still default to an internal battery monitor or no monitor. It’s recommended to check Settings → System Setup → Battery Monitor and ensure the JK BMS is selected as the battery data source (instead of “No battery monitor” or a BMV sensor). One forum expert advised that the battery should appear first in the Cerbo’s device list and be selected, otherwise the inverter will charge based on its own static settings (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community). In summary, verify that the Victron system knows to use the JK BMS readings (voltage, SoC, etc.) for control.
  • Integration via Venus OS Driver (Optional): One user (hdv) achieved integration by installing the open-source dbus-serialbattery driver on a Cerbo GX (Venus OS) (JK BMS + Multi RS Solar protocol issue – DIY – Victron Community). This driver allows various BMS (like JK) to communicate over serial or BLE if not using direct CAN. In that setup, the JK BMS was connected using a serial link and the driver translated the data to Victron’s D-Bus. After enabling DVCC, the result was the same – the Multi RS saw a managed battery and followed the BMS limits. This approach can be useful if the CAN bus method is problematic; however, in hdv’s case the CAN was also utilized (they mention setting the CAN-bus to 500 kbit) (JK BMS + Multi RS Solar protocol issue – DIY – Victron Community). The takeaway is that whether via native CAN or a Venus OS driver, the BMS data needs to get into the GX device, and then DVCC will let it control the Multi RS.

Successful Integration Experiences

Users have reported successful connections once the above configurations were in place:

Common Issues and Troubleshooting Tips

Despite successful reports, a few recurring issues have been noted by users during setup. Here are common problems and how they were resolved:

One user had no TX/RX traffic on the Cerbo’s BMS-CAN until realizing the BMS was still in protocol 2; switching to protocol 4 immediately fixed that (Cerbo GX BMS-CAN – JK Inverter BMS not visible – DIY – Victron Community). Also, use the BMS-CAN port on Cerbo GX set to 500kbit/s for the JK BMS (Cerbo GX BMS-CAN – JK Inverter BMS not visible – DIY – Victron Community). The VE.Can port (250kbit) on the Cerbo is generally for Victron devices like the Multi RS or MPPT – the BMS should go on the separately configurable port.

Finally, adding proper termination resistors on the CAN bus ends is important for reliability (the Cerbo’s BMS-CAN port may need an external terminator if it’s one end of the CAN chain) (Cerbo GX BMS-CAN – JK Inverter BMS not visible – DIY – Victron Community).

What is a terminator In a CAN bus system, a terminator is simply a resistor (typically 120 Ω) that’s placed at the end of the cable run. Its job is to “absorb” the signals and prevent them from bouncing back (or “reflecting”) along the cable, which could interfere with proper communication between devices.

  • Inverter Data (PV/Load) Disappears When BMS Connected: This issue was reported when a user tried to tie the JK BMS into the same CAN network as the Multi RS. After switching the Multi RS to “CAN-bus BMS” mode, the Cerbo GX no longer showed PV production or load on the Multi RS (JK BMS + Multi RS Solar protocol issue – DIY – Victron Community). The fix was to separate the CAN buses due to the speed difference as described earlier. Do not put the BMS and Multi RS on one continuous daisy-chain unless you configure them to the same baud rate. In practice, the Multi RS stayed on the VE.Can bus (250k), and the JK BMS was isolated on the other CAN interface at 500k (JK BMS + Multi RS Solar protocol issue – DIY – Victron Community). Once this was done, the Multi RS data returned and the BMS info was also available – the GX could see everything concurrently. In summary, if enabling the BMS on CAN makes other devices “vanish” from the network, it’s likely a CAN conflict; use separate ports or matching speeds to resolve it (JK BMS + Multi RS Solar protocol issue – DIY – Victron Community).

  • BMS Detected but Charger Not Following BMS (No DVCC): Another common pitfall is forgetting to enable DVCC (in older Venus OS versions, enabling “BMS support”). Without DVCC, the Victron inverter/charger will display the battery’s info (like SoC) but will not obey the BMS’s charge/discharge limits. For example, one person’s Multi RS was charging based purely on the default voltage settings, since the system wasn’t actually in “BMS-controlled” mode (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community). The Victron community recommended turning on DVCC and selecting the BMS as the controlling battery (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community). After doing so and rebooting the Cerbo GX, the Multi RS began taking power from solar and charging the battery properly, no longer stuck in an idle state. Ensure “Enable DVCC” is on, and “Shared Voltage Sense” / “Allow BMS to control charge” are enabled as appropriate. On the Multi RS display or Remote Console you should then see indicators that the battery is managed by BMS (e.g. charge voltage may show as externally limited). If you don’t see a “BMS” or “External” status, double-check DVCC settings. As one forum user put it: “Your system is not under the control of the battery’s BMS – you need to solve that first” (Nearly no solar preference after factory reset – Multi RS – DIY – Victron Community).
  • Over-Voltage Protection (OVP) Trips / Charging Cuts Off: Some users have encountered the BMS cutting off charging (hitting OVP) or a rapid on-off behavior when the battery is near full. A JK BMS integrated with Victron will typically stop charge once any cell hits the over-voltage threshold. If the Victron charging voltage is set too close to that threshold, you can get an overshoot or oscillation. In one DIY Solar thread, a user’s 16S LiFePO4 with JK BMS would reach about 100% and then oscillate between charging and discharging every few seconds at float (Jk BMS jumping charging discharging – Q&A and troubleshooting – Victron Community). This was attributed to the BMS constantly toggling at the max voltage. The community identified two main culprits for OVP issues: (1) cell imbalance – if one cell is weaker and hits 3.65 V early, it triggers OVP while others are lower; (2) charge voltage set too high – pushing the battery to the very edge of 100% (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum). The recommended solutions were: balance the battery (and check JK BMS active balancing settings) and reduce the charge voltage slightly (for instance, instead of 3.65 V/cell (58.4 V total) set about 3.60–3.62 V/cell (57.6–57.9 V) as the charger target) (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum). One responder suggested running the system “open-loop” (no BMS comms) temporarily to manually adjust absorb/float to a safer level (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum). In practice, many users set the JK’s per-cell charge limit (RCV) a bit below the hard OVP, and/or configure Victron’s absorption a tad lower, to prevent the JK from ever having to disconnect abruptly. When properly tuned, the Multi RS will taper off charge as the BMS requests and not hit the OVP in the first place.
  • State of Charge Sync and Shunt Use: The JK BMS provides its own State of Charge (SoC) calculation to Victron. Some have noted that relying on the BMS’s SoC is generally fine (especially if the JK BMS is calibrated), but others prefer using a Victron SmartShunt or BMV for more accurate readings. In one case, a user asked if a smart shunt was “required” when using the JK BMS as the monitor; the consensus was that it’s not required, but a dedicated shunt can sometimes smooth out any quirks in SoC reporting (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum) (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum). The JK BMS’s SoC can drift if the battery sits at full charge for a long time (common to many BMS), whereas a Victron coulomb-counter might be more precise. However, this is more of an optimization – many have run ESS systems with just the JK BMS data successfully (Battery overcharging hitting OVP – JK BMS + Victron RS450/200 | DIY Solar Power Forum). The important thing is to ensure whichever monitor you use (JK or a Victron BMV) is selected in the GX settings so that the Multi RS uses that for decision-making.

References and Forum Discussions

The insights above are drawn from community knowledge and specific forum threads where users documented their JK BMS + Victron setups:

By following the community’s guidance – correct wiring (use the CAN port and Victron cable), proper protocol settings (JK protocol #4), separating CAN networks to handle 500 k vs 250 k baud, and enabling DVCC for BMS control – many users have achieved a stable integration of the JK-PB2A16S20P BMS with the Victron Multi RS 48/6000. This allows the Victron inverter to safely charge and discharge the LiFePO4 battery bank under the supervision of the JK BMS, combining Victron’s robust power electronics with JK’s battery management at a fraction of the cost of Victron’s proprietary batteries.

Overall, the consensus from these forums is that the JK BMS and Multi RS are compatible over CAN bus, but it requires careful setup. Once configured, the system works well, with the BMS reliably providing SoC and protecting the battery, and the Multi RS delivering solar and inverter power optimized by those BMS inputs. The linked discussions (see citations) provide more detail and even screenshots from successful setups for those seeking to replicate this integration.

Sources: