Connecting CANBus between an original Redflow BMS and a Victron Energy CCGX

Note: These are deprecated instructions for the original BMS hardware. See this article for the current BMS hardware CANBus guide

CANBus interfacing using the original BMS model (not applicable for current BMS hardware)

The original version of the BMS had no built-in CANBus port, and it needs to be interfaced using an external USB-CANBus dongle.

The original BMS hardware can in principle use any USB-CANbus adaptor which follows the 'SocketCAN' specification.

The specific device we we have used successfully (and recommend) is this one - available from 8devices.

Update May 2019: There is a new version of this product now, that costs less and looks even more nifty - but should be functionally identical.  It is the Korlan USB2CAN device (same manufacturer). That said, all new installations with Redflow should normally use the newer Redflow BMS that has a built in CANBus port. 

The 8devices USB2CAN product has an LED that can be interpreted as follows:

• Fast blink vs slow blink vs solid green - unconnected / connecting / good+working
• Red == BMS not connected to CANBus adaptor
• fast green means not connected to CCGX
• slow green means connecting, solid green means fully operating

Consult the pinout of the USBCAN device (see attachment below).

• Wire USBCAN CANH to RJ45 pin 7 (Brown/White)
• Wire USBCAN CANL to RJ45 Pin 8 (Brown)
• Wire USBCAN Ground to RJ45 Pin 3 (Green/White)

Plug the USBCAN device in to any BMS USB port except for port 4 (i.e. into ports 1, 2 or 3) - see the port picture below) for the USB port assignments on the BMS.

Important Note: You need to reboot the BMS after plugging in the USBCAN device or it will not work. An easy way to reboot is to go to the Configuration-> Date and Time menu and press Confirm on this page to reboot the BMS. 

USB port numbering on the BMS (As above - avoid using port 4):