Connecting REC Q BMS to Sunny Island 6048-US Inverter


  • Which cable do I use?


  • From what I could find I would suggest you use a REC to Victron cable and then adapt the RJ45 end for the Sunny pinout. link to cable:    https://www.offgridsoftwaresolutions.com/product/rec-victron-canbus-cable/ And here are the REC and Victron pinouts for reference. https://community.victronenergy.com/storage/attachments/16425-1610903384110.png And here is what the it looks like the Sunny uses.  You will want to confirm this with your manual.
    • Sunny Island  RJ45 pin 4 connects to Can-H >>> REC DB9 pin 7 Sunny Island  RJ45 pin 5 connects to Can-L  >>> REC DB9 pin 2
    • Sunny Island RJ45 pin 2 connects to GND  >>> REC DB9 pin 3
    Only the Sunny Island CAN communication interface is connected to the BMS, the second communication line – SYNC Bus apparently is not used. Extract from Sunny Island configuration of RJ-45 plug \"ComSyncIn\" of : Pin Signal 1 Sync1 – reserved 2 CAN_GND 3 SYNC_H 4 CAN_H 5 CAN_L 6 SYNC_L 7 Sync7 – reserved 8 Sync8 – reserved   And to make it easy, I would grab something like this from an online electronics store: LYUMO DVR Ethernet Connector RJ45 Female Jack to 8 Pin ... Please let us know if this works for you!

  • I will see what I can do.  Thanks

  • We have now arranged to have the REC BMS to Sunny CANBus cables manufactured and stock should start arriving mid April 2022 https://www.offgridsoftwaresolutions.com/product/rec-sunny-canbus-cable/ Thanks,   Rick

  • i cuted the wire and rearrange the order. am i do it right? what is this extra connector for? looks like pin 1 and 2 is connected together. do i need both for my SI?

  • The blue RJ45 looks like a terminator for your Victron end of the network. For your cable you can rewire the RJ45 or it might be easier to open up the DB9 connector and resolder your connections there, depending on what equipment you have to work with.

  • it for the Sunny Island. am i make the connection right?

  • Ok, I have the parts, does this look correct.  What about termination?  

  • I was thinking more like you could cut off the blue RJ45 and just wire it in directly, but that looks like it will work. There is a terminator built into the REC cable and you may have received one with your Inverter.  If not, its easy to just put a 120 ohm resistor across  CAN H and CAN L on your new connector.

  • I know what to do now and that makes sense.  I will rewire it like you suggested.  Thanks!

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