What Are Anderson Style Connectors?

Anderson style connectors — sometimes called Anderson plugs or SB connectors — are heavy-duty, single-pole electrical connectors designed for high-current DC applications. Originally developed by Anderson Power Products, the design has become an industry standard across the automotive, solar, and off-road sectors.

Each connector consists of two housings — each containing a single contact — that snap together to form a secure, polarity-neutral connection. They’re genderless, meaning both sides are identical and either can act as plug or socket. The housings are typically made from thermoplastic rated for heat and UV resistance, with silver-plated copper contacts for excellent conductivity.

In Australian 4WD culture, the 50A grey Anderson connector has become the universal standard connection point for auxiliary power — you’ll find them on everything from DC-DC chargers to solar regulators, jump starter leads, and tow vehicle–to–trailer connections.

Why Anderson Connectors Are the Go-To for 4WD Wiring

Choosing the Right Amp Rating

Anderson style connectors come in a range of current ratings. Choosing the wrong size is one of the most common wiring mistakes — undersizing leads to heat and failure, oversizing leads to wasted space and unnecessary cost.

For the vast majority of 4WD auxiliary setups — dual battery systems, DC-DC chargers, portable fridges, and solar panel inputs — the 50A grey Anderson connector is the correct and standard choice.

Colour Coding: What Do the Different Colours Mean?

Anderson style connectors come in multiple colours, and while there’s no universal mandatory standard, a widely adopted convention has evolved across the Australian 4WD and solar industries. Following this convention prevents costly connection errors:

Using different colours at each connection point in your build means you can see at a glance what connects where — invaluable when diagnosing issues in the dark on a remote track.

Correct Wiring: The Steps That Matter

A correctly wired Anderson connector is safe, reliable, and lasts for years. Here’s how to do it properly:

• 1 Match your wire gauge to the connector rating. For a 50A connector, use a minimum of 6mm² cable. Undersized cable causes resistance, voltage drop, and heat. For runs over 4 metres, step up to 8mm².
• 2 Strip and tin the cable end correctly. Strip back approximately 10–12mm of insulation. Twist the strands tight, then tin with solder if you’re crimp-and-solder connecting. Do not nick or reduce the wire strands.
• 3 Crimp the contact firmly. Insert the cable into the Anderson contact and crimp with a proper ratchet crimping tool. A poor crimp is the number one cause of high resistance, heat, and eventual failure. Verify by tugging the wire — it should not pull free.
• 4 Insert contacts into the housing correctly. Slide each crimped contact into the housing until you hear or feel it click and lock into place. A contact that isn’t fully seated will arc and burn over time.
• 5 Use heat shrink over the entry points. Apply adhesive-lined heat shrink over the cable entry on each housing to provide strain relief and moisture protection — especially for underbonnet and exposed locations.
• 6 Fuse the circuit close to the source. Always install an appropriately rated fuse or circuit breaker within 300mm of the battery positive terminal. For a 50A circuit, a 50A ANL fuse or blade fuse is appropriate.

Where Anderson Connectors Are Used in a 4WD Build

Understanding where Anderson connectors fit into a typical 4WD electrical build helps you plan your wiring correctly from the start:

Dual Battery System. The most common application. The output side of your DC-DC charger connects to your auxiliary battery via a 50A Anderson connector, allowing the circuit to be isolated or connected quickly without tools.

Solar Panel Input. Portable solar panels almost universally terminate in an Anderson plug — typically yellow or grey 50A. The input to your solar regulator or battery accepts the same. This lets you connect and disconnect your solar blanket or panel in seconds.

Inter-vehicle Jump Starting. Many 4WDers run an Anderson-terminated jump lead set between vehicles — far more reliable and cleaner than traditional jumper cables clipped to terminals.

Trailer and Caravan Power. An Anderson connector on the drawbar of a trailer or caravan allows the tow vehicle’s auxiliary battery to charge the trailer battery while driving — standard practice for serious touring setups.

Portable Fridge and Accessory Leads. Running a dedicated Anderson socket inside or on the exterior of your vehicle gives you a clean, high-current connection point for a portable fridge, air compressor, or other accessories without patching into your vehicle’s 12V sockets.

Common Anderson Connector Mistakes to Avoid

• ! Using undersized cable. The connector itself may be rated to 50A, but if you’re running 4mm² cable, your cable is the weak point. Always size the cable to the load and run length, not just the connector rating.
• ! Skipping the fuse. An unfused Anderson lead is a fire waiting to happen. If the cable shorts between the battery and the connector, an unfused circuit will carry as much current as the battery can deliver until something burns or melts.
• ! Poor crimping. Using incorrect crimp tools — or worse, pliers — produces a cold joint that corrodes and fails under vibration. Invest in a proper ratchet crimping tool and use the correct die for your contact size.
• ! Connecting under full load. Avoid connecting or disconnecting Anderson plugs under heavy load. The resulting arc degrades the contacts over time. Switch off the load before connecting.
• ! No colour coding or labelling. A grey Anderson connector looks identical to every other grey Anderson connector. Use colour-coded housings for different circuits and label cables clearly so any future troubleshooting is straightforward.

Frequently Asked Questions