Hi Marc, Most of the time when I have a problem like this, I just forgot the canbus resistor to plugin, thus no good communication or the bus speed not properly selected as there is 250 and 500baud coms.
Try to connect 1 battery first. And what battery are you trying to connect to? Is that battery compatible with Victron CCGX, check battery compatibility page. Not every battery that has canbus follows the same protocols, thus maybe your batteries not compatible.
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