ARCO Zeus A275L 3.15-Inch Alternator, Isolated Ground

The ARCO Zeus A275L (3.15" Foot, with Isolated Ground & Terminal Block) is the highest power output alternator in its size and class. It is designed for boaters who want high energy production suitable for marine, RV, military, and commercial applications, rapidly charging large battery banks.

Running 8-20% cooler than incumbent alternators thanks to heat shedding coatings, an exterior-mounted rectifier, dual cooling fans, and OEM components, this alternator is optimized for performance at idle speeds and reduces the need for a generator by creating additional power with your engine. Models are available with internal or external voltage regulator to match your setup. E-Coat/Cerakote finish absorbs less heat for sustained amperage, SAE J1171 certified and made in the USA. Browse more options in our alternators and charging hardware category.

Key Features: Large frame, External-only regulation via terminal block, 8-20% cooler operation, SAE J1171 certified, made in USA.

Frequently Asked Questions

How does this alternator stay cooler than competitors? Heat shedding coatings, an exterior-mounted rectifier, dual cooling fans, and OEM components — 8-20% cooler.

What regulation does this alternator use? External-only regulation via terminal block.

Where is this alternator made? The USA, SAE J1171 certified.