ARCO Marine Zeus A275L J-180 4" Alternator, 12V 311A Max – Made in USA

Unleash robust power and superior charging performance with the ARCO Marine Zeus A275L J-180 4" Alternator. Engineered for high energy production and the coolest operating temperatures in its class, this alternator is designed for demanding applications across marine, RV, military, and commercial sectors. Its advanced E-Coat/Cerakote finish and dual cooling fans ensure sustained high amperage output, rapidly charging large battery banks and reducing the need for an auxiliary generator. Proudly made in the U.S.A. and SAE J1171 Certified, it delivers proven dependability for your critical systems. Upgrade your power system today for unmatched reliability.

In the Box:

• ARCO Marine Zeus A275L J-180 4" Alternator
• Standard 49K6 (6-groove, 49mm) Pulley
• M17 x 1.5 x 24mm Nut
• 18mm ID x 29mm OD Washer
• Terminal Block and P-Type Harness for External Regulation

Key Benefits & Specifications:

• High Power Output: Delivers a maximum cold output of 311 Amps at 9,000 RPM, with sustained cruising output of 227 Amps (hot, 6,000 RPM) and 198 Amps at idle (hot, 3,000 RPM) for rapid battery charging.
• Superior Thermal Management: Features E-Coat/Cerakote finish and dual cooling fans, allowing it to run 8-20% cooler than comparable alternators for sustained high amperage output and extended lifespan.
• Durable Construction: Maintains maximum continuous operating temperature up to 110°C / 230°F, ensuring reliability in harsh conditions.
• Optimized Idle Performance: Provides significant amperage even at low engine speeds, reducing reliance on a generator.
• SAE J1171 Certified: Meets industry safety standards for marine ignition protection.
• Made in the U.S.A.: Guarantees high-quality manufacturing and dependability.
• External Regulation: Designed for use with an external regulator (terminal block and P-type harness included) for precise control over charging.
• Robust Mounting: Features a J180 4-inch saddle mount for secure installation.
• Compact & Lightweight: Weighs 14.9 lbs / 6.7 kg, designed for efficiency without excessive bulk.
• Secure Battery Connection: Equipped with an M8 thread side-mount battery post.

Compatibility & Pairings:

• Direct Replacement: Replaces most Volvo Penta alternators using a 4-inch J180 saddle-style mount.
• Recommended Regulator: For maximum performance and optimal lithium battery charging, pair with an ARCO Zeus Bluetooth alternator regulator.