The pinout from the battery BMS does not contain a ground. The Cerbo GX shows a ground.
May I wire the Cerbo GX connector with only the CAN H and CAN L and no GND?
Do I use the remote LED Negative wire from the BMS as the Cerbo ground?
asked
CanBus Pinouts
Hi @msmolow,
yes. Only use CAN-H and CAN-L. No other wires.
As far as I remember from a Victron document it is recommend to not wire the GND to prevent ground loops.
My SeeLevel N2K tank system required a ground connection to work. I believe this is because the Ve.Can output of my CCGX is isolated. The same is also true for my CANable USB adapter I'm now using with my Raspberry Pi running Venus.
So if you don't get any data without a ground, try connecting the Ve.Can ground pin to something like the chassis or the battery negative (or in your case the LED negative pin in the connector.
Now that you say isolated VE.Can port on the CCGX, these ports on the Cerbo GX are not isolated and this was the reason to leave the GND off.
I had my own erratic moments with a diy cable between Cerbo and NMEA 2000 until I removed the ground wire.
Thanks all. It turns out it's an academic discussion. The BMS is RV-C, which I just read Victron does not support.
