Arco Starting & Charging 4024 Zeus A275L J-180 4" Marine Alternator with Regulator

The Arco Zeus A275L J-180 is a high-output 12-volt marine alternator engineered to deliver exceptional power production in a compact 4-inch saddle-mount design. This American-made alternator is purpose-built for demanding marine, RV, military, and commercial applications where reliable charging performance is critical.

Superior Cooling Technology:

The A275L runs 8-20% cooler than conventional alternators through advanced thermal management, including heat-shedding Cerakote or E-coat finish, dual cooling fans, and an innovative housing design that acts as a heat sink. Cooler operation translates directly to sustained high-amperage output and extended service life.

Impressive Power Output:

• Maximum output of 311 amps at 9,000 RPM (cold)
• Sustained cruising output of 227 amps at 6,000 RPM (hot)
• Sustained idle output of 198 amps at 3,000 RPM (hot)
• Optimized performance at low RPM eliminates the need for auxiliary generators
• Rapidly charges large battery banks with consistent power delivery

Technical Specifications:

• 12-volt system with 14.1V default output voltage
• 138mm stator size with 16 rotor poles
• Internal/external regulation capability (internally regulated with adapter for optional external regulator)
• 12 avalanche-rated diodes (6 positive, 6 negative, 50A rated)
• Cut-in at 1,061 alternator RPM; maximum 19,000 RPM
• Standard 49K6 pulley (6-groove, 49mm) on 17mm diameter shaft
• M8 threaded battery post with side mount configuration
• Maximum continuous operating temperature: 230°F (110°C)
• SAE J1171 certified

Application:

Designed to replace most Volvo Penta alternators using a 4-inch J-180 saddle-style mount. Compatible with ARCO Zeus Bluetooth alternator regulators and lithium battery charging systems for maximum performance optimization.

Made in the U.S.A. with premium components for reliability in harsh marine environments.