4 AWG Battery Cable

A 4 AWG battery cable is the link between the parts of an off-grid system: battery to battery, battery to inverter, and charger to the bank. It is supplied as a matched red and black pair, so both sides of a run come from one order, and the length is made to the installation rather than cut down on site.

The conductor is pure copper rather than copper-clad aluminium. A 12V system draws a large current for the same power, so the resistance of the conductor decides how much voltage is lost along the run: an aluminium conductor carries less current through the same cross-section, turns the difference into heat, and puts aluminium at every cut end where it oxidises.

Both ends carry a 3/8″ (9.5 mm) ring terminal with heat-shrink tubing already fitted. The shrink seals the joint at the point where moisture would otherwise reach the strands. The bore is intentionally a little larger than the stud it bolts onto, because the current passes through the flat clamping face and not through the hole, which is why the nut has to be tight and the face clean.

PVC insulation with a tin-plated jacket covers the run itself, and the pair is used across battery, solar, marine and inverter wiring. Lengths are made to order and OEM or ODM builds are accepted, so a batch can be cut to the lengths an installation actually needs instead of being spliced from standard reels.