6m one way distance, 12m total, 50A, 35mm2, 0.34V 2.8% loss. 3% voltage drop.is perfectly acceptable, 25mm2 would be minimum acceptable size for this length. Is your 6m the distance from batteries to the Orion or the positive plus negative cable total length. Many calculators like the one I show, you input the distance between devices and it automatically doubles this for the voltage drop calc.