Connecting a victron 12 2000 80, a victron 30 amp mppt, an victron 12 18 dc to dc and a victron 702

[Kin2121]

I use high grade battery 2/0 cable for the battery connections, bus bar to battery inverter to bus bars and on the house side dc voltage abs I use 2 gauge to alternator and for everything except the moot and dc to dc our where I use a fine stranded copper 10 gauge wire