ARCO Zeus A225S Vortec Alternator with Regulator

Description

The ARCO Zeus A225S Vortec Alternator with Regulator delivers high-output 12V charging in a smaller frame for marine, RV, military, and commercial systems with large battery banks. Its Vortec/GM pad-mount configuration is designed to replace Mando-type alternators found on many MerCruiser and Volvo Penta GM-block engines while providing substantially more charging capability than a conventional replacement alternator.

The A225S is engineered for sustained power production with thermal management features normally associated with larger high-output systems. Heat-shedding E-Coat or Cerakote finishes, an externally located rectifier, dual cooling fans, and OEM components help the alternator run approximately 8-20% cooler than incumbent designs. It is also optimized for idle-speed performance, allowing the engine to generate useful charging power without relying as heavily on a separate generator.

This small-frame model uses a 130mm stator, 16 rotor poles, a P-type field, and internal/external regulation. The alternator operates with internal regulation but can be paired with an ARCO Zeus Bluetooth Alternator Regulator for more advanced charging control or lithium battery charging. Default output voltage is 14.1V.

ARCO lists maximum cold output of 254A at 9,000 alternator RPM, sustained hot cruising output of 187A at 6,000 RPM, and sustained hot idle output of 157A at 3,000 RPM. Cut-in speed is 1,061 alternator RPM and maximum alternator speed is 19,000 RPM.

The drive and electrical hardware includes an M8 side-mount battery post, 49K6 six-groove 49mm pulley, 17mm shaft threaded M17 x 1.5, included pulley nut and washer, and six positive plus six negative 50A avalanche-rated diodes.

Mounting compatibility includes listed MerCruiser and Volvo Penta 3.0GLM, 3.0GLP, 4.3GXi, 5.7GiL, and 5.7GXiL GM-block engines using the Vortec/GM pad pattern. The alternator is SAE J1171 certified and made in the USA. More options in our marine alternators.