​DCDC Cable & Accessories

For a 40A charger, 6 B&S (roughly 13.5mm²) is the standard cable size for runs up to five metres. This gauge is thick enough to handle the high current without significant voltage drop, which is critical for making sure the auxiliary battery reaches a true 100 percent state of charge.

If you are mounting the charger further away, such as in a camper trailer or at the rear of a long wagon, stepping up to 4 B&S (20mm²) is a smart move. Using cable that is too thin leads to heat buildup and a drop in charging efficiency, meaning your fridge might struggle or your batteries take much longer to recover after a night at camp.

Explore our heavy duty Battery Cable for custom lengths, or see our pre-sized Battery Wiring Kits for a simplified setup.

You must install a fuse at both ends of the main positive cable, as close to the battery terminals as possible. One fuse goes within 300mm of the starter battery, and another goes within 300mm of the auxiliary battery.

This setup protects the entire length of the cable from short circuits. Because power can come from both the alternator and the house battery, a fault in the middle could lead to an electrical fire if only one side is protected. Using the correct fuses provides a safety barrier for your wiring and your vehicle, especially when traveling over rough corrugated tracks.

Find the right protection in our Circuit Breakers & Fuses collection, or see your live charging status with our Battery Monitors.

MIDI fuses are better for DC DC chargers because they use a bolt down connection. This mechanical fix is superior to the push fit design of a Maxi fuse, especially when your vehicle faces constant vibration on corrugated outback tracks.

The bolt down terminals on a MIDI fuse holder create a low resistance connection that reduces heat and prevents voltage drop. This is a practical advantage for chargers that run at high amperage for several hours during a drive. While Maxi fuses are easy to swap, they can sometimes work loose or suffer from poor contact over time. Choosing a MIDI setup helps maintain a steady flow of power to your auxiliary battery.

Explore our full range of Circuit Breakers & Fuses to find the right protection, or see our compatible DCDC Chargers to match your hardware.

Hard-wiring is the preferred choice for permanent installations such as those inside a 4WD canopy or a caravan. A direct, fused connection reduces the risk of voltage drop and removes a potential point of failure that can occur with a plug that might vibrate loose on rough roads.

Anderson plugs are more practical if your setup needs to be portable or if you plan to move the charger between different vehicles. They allow for quick and easy disconnection but require regular checking to ensure the terminals stay clean and secure. For most fixed builds, a hard-wired setup provides the best stability and charging performance for your auxiliary power system.

Explore our range of accessories to find the right components for your build.