The ARCO Zeus A275L High Output Alternator is a powerhouse designed to meet the rigorous demands of marine, RV, military, and commercial environments. With a peak cold output of 310 amps at 9,000 RPM, it offers unparalleled power density in its class, ensuring your battery bank charges rapidly and maintains power under heavy loads. Proudly made in the USA, the A275L is engineered to perform reliably in extreme conditions, ideal for applications where high energy production is essential.

Key Features:

• High power output of up to 310 amps (cold) and 198 amps (sustained idle)
• Runs 8-20% cooler due to dual fans, heat-dissipating coatings, and exterior-mounted rectifier
• E-Coat and Cerakote finishes
• Compatible with ARCO Zeus Regulator for lithium battery charging
• SAE J1171 certified
• Built with OEM-grade, high-density stator, 16-pole rotor, and robust diodes
• Standard 49 mm 6-groove pulley, with optional 50 mm clutch pulleys

Heat Dissipation for Optimal Efficiency

Equipped with heat-shedding coatings, a rectifier positioned on the housing exterior, and dual cooling fans, the A275L alternator operates 8-20% cooler than conventional units. This enhanced cooling capability increases overall performance, allowing for sustained high output even in hot conditions. The Cerakote or E-Coat finish further assists in keeping the alternator cool, maintaining an efficient and stable power flow, which is crucial for extended periods of operation.

Flexible and Precision-Controlled Output

The A275L offers flexibility with internal or external regulation options, making it adaptable for various system configurations. Operating at an optimal 14.1V default output voltage, it ensures precise control over power delivery, protecting sensitive electronics and delivering power efficiently. It also includes an advanced ARCO Zeus Alternator Regulator for maximum output, particularly beneficial when charging lithium battery systems.

Built for Peak Performance at Idle

Optimised for low RPM performance, the Zeus A275L is designed to produce substantial power at idle speeds, with a sustained idle output of 198 amps at 3,000 RPM. This capability reduces the need for a generator in many setups by efficiently creating additional power while your engine runs at lower speeds. The alternator’s performance curve is carefully calibrated, ensuring ample power at all RPM ranges.

Versatile Mounting Options and Compatibility

The A275L comes in multiple mounting configurations to suit a variety of applications, such as the 3.15” J180 saddle mount compatible with numerous marine engines. It also features a standard 49 mm K6 pulley with an optional 50 mm clutch pulley for enhanced versatility. This wide compatibility makes it a suitable replacement for many OEM alternators across various engine platforms, from Ford Transit and GM Vortec to Mercedes and BMW systems.

Rigorous Testing for Transparent Performance

ARCO Marine subjects the Zeus A275L to rigorous testing to ensure consistent performance under extreme conditions. By evaluating the alternator’s sustained “hot” output at 3,000 RPM for extended periods, ARCO guarantees that its power output remains stable when the alternator reaches its maximum operating temperature, providing transparency and reliability you can count on.

Comprehensive Warranty and Support

The ARCO Zeus A275L comes with an industry-leading warranty, covering parts and labour for one year, with an option for an additional year if registered within 30 days of purchase. This best-in-class warranty reflects ARCO's commitment to quality and customer satisfaction, providing peace of mind for those who rely on dependable power solutions.