4B&S (20.29mm²) Black Single Core Automotive Cable: High-Current Conductor for 12V, 24V, and 48V Systems

Engineered for Demanding Automotive and Off-Grid Power Applications

This 4B&S (20.29mm²) black single core automotive cable is designed to deliver reliable, high-current power in 12V, 24V, and 48V DC systems. With a robust 135A rating at 30°C (derating factors apply), it is an excellent choice for automotive battery and starter wiring, DC-DC charger installations, MPPT solar charge controllers, and high-power inverter connections. The cable's oxygen-free copper conductor and durable 90°C rated PVC insulation ensure efficient power transfer and long-term reliability in harsh under-bonnet and mobile environments.

Unlike standard electrical wire, this cable is built to withstand the vibration, heat, and flexing common in 4WD, caravan, marine, and heavy vehicle applications. Its fine-stranded construction (252/0.32mm) provides excellent flexibility for routing through tight spaces, while the thick insulation resists abrasion, oil, and fuel exposure. Whether you're upgrading your dual battery system, wiring a high-output alternator, or connecting a large inverter, this cable provides the current-carrying capacity and durability needed for critical power circuits.

Key Features

• 135A current rating at 30°C (JASO D609 standard) for high-demand circuits
• 20.29mm² cross-sectional area (approx. 4 AWG equivalent) with fine-stranded 252/0.32mm copper for flexibility
• Oxygen-free copper conductor minimises voltage drop and resistive heating
• 90°C continuous temperature rating for under-bonnet and high-heat environments
• RoHS compliant and manufactured to Australian/NZ standards for safety and quality assurance
• Sold per metre for custom-length installations without waste

Optimised for High-Current DC Systems

In 12V automotive systems, voltage drop is a critical concern. This cable's low electrical resistance (0.9 ohm/km at 20°C) helps maintain system voltage over longer runs, ensuring your battery chargers, inverters, and solar controllers operate efficiently. It is suitable for 24V and 48V systems as well, with a maximum DC voltage rating of 120V, making it versatile for off-grid solar setups, truck electrical systems, and marine applications.

The 4B&S gauge (20.29mm²) is a popular choice for auxiliary battery wiring, winch power cables, and high-amperage accessory circuits. Its robust construction reduces the risk of overheating and insulation failure, even when bundled or installed in hot engine bays. *Note typical derating factors apply: when multiple cables are bundled or ambient temperatures exceed 30°C, the current-carrying capacity must be adjusted according to the provided derating tables.

Built for Australian Conditions

Manufactured to meet stringent Australian and New Zealand safety standards, this cable is engineered for the unique demands of the Australian market. From corrugated outback tracks to coastal marine environments, the insulation resists degradation from UV exposure, moisture, and chemicals. The fine-stranded copper conductor withstands repeated flexing without work-hardening or breaking, a common failure point in inferior cables.

For installers and DIY enthusiasts, the cable's 8.3mm outer diameter is compatible with standard 3/8"-16 (approx. M10) stud terminals and heavy-duty lugs up to 4/0 AWG (approx. 95mm²). This ensures secure, low-resistance connections in fuse blocks, busbars, and battery terminals.

Applications

• Automotive battery and starter motor cables for cars, 4WDs, trucks, and buses
• Dual battery system wiring with DC-DC chargers and smart isolators
• High-power inverter connections up to 2000W (depending on cable length and voltage)
• Solar charge controller to battery bank wiring in off-grid and mobile setups
• Marine electrical systems requiring tinned copper alternatives (verify suitability for marine use)
• General high-current DC power distribution in custom vehicle and equipment builds

Upgrade Your Power System with Confidence

Select the 4B&S (20.29mm²) black single core automotive cable for your next installation and experience the difference that quality materials and precise manufacturing make. Add the required length to your cart and build a power system that delivers when you need it most.