Balmar 24V 70A 60 Series Alternator, 4in Saddle Mount, Dual V Pulley, Isolated Ground

Balmar 604 Series 70A 24V Marine Alternator

Reliable Isolated Ground Charging for Recreational Vessels

The Balmar 604 Series 70A 24V Alternator (B-604-24-70-DV) is a compact, high-output alternator from Balmar's 6-Series. Balmar designs its 6-Series alternators for recreational applications and describes them as ideal for modest charging upgrades. It has a 4in (approx. 101.6mm) J-180-style saddle mount (dual foot), the mounting style Balmar lists as typical for Caterpillar, Cummins, Detroit Diesel and John Deere engines.

Operating at 24V with a 70A output, it provides dependable power generation to keep navigation, communication and onboard house systems running. For 24V applications, Balmar specifies a Max Charge multi-stage regulator.

Key Features and Technical Benefits

• Isolated Ground Architecture: Helps prevent stray current corrosion and galvanic damage in metal-hulled vessels by keeping the electrical return path completely separate from the engine block.
• 4in (Approx. 101.6mm) J-180 Saddle Mount: J-180-style dual-foot mounting configuration for engines with a 4in saddle bracket.
• Dual Deep Vee Pulley: Accommodates twin belts to maximise surface contact, significantly reducing belt slippage and premature wear when driving high-load 24V electrical systems.
• Typical Engine Applications: Balmar lists this mounting style as typical for Caterpillar, Cummins, Detroit Diesel and John Deere engines. Check your engine bracket before ordering.
• Dual Fan Cooling: Compact, small-case 6-Series design with dual fan cooling and a high airflow frame.

Why Upgrade to an Isolated Ground Balmar Alternator?

In marine environments, particularly on aluminium or steel-hulled vessels, using a standard case-grounded alternator introduces significant risks of electrolysis and rapid hull degradation. The isolated ground terminal on the B-604-24-70-DV ensures that all charging currents return directly to the battery bank via dedicated cabling rather than passing through the engine block and drivetrain. This reduces the risk of costly galvanic corrosion and protects sensitive onboard electronics from ground-loop interference.

Furthermore, driving a 24V alternator under heavy load requires substantial mechanical torque. A single belt often slips under these conditions, leading to glazed belts, black dust accumulation in the engine bay, and undercharged batteries. The inclusion of a dual deep vee pulley distributes the mechanical load across two belts, ensuring reliable power transfer during long passages.

Ideal Applications

This model suits:

• Cruising Vessels: Motor yachts and long-range cruisers running 24V house and starting banks on engines with a 4in J-180-style alternator mount.
• Metal-Hulled Yachts and Cruisers: Aluminium and steel vessels where an isolated ground charging circuit is preferred.

Data sheet: Balmar 6-Series alternator data sheet (PDF)

Upgrade Your Charging System Today

Ensure your vessel has the dependable 24V power generation it needs. Order the Balmar 604 Series 70A Alternator today for a durable, isolated-ground charging solution for engines with a 4in J-180-style mount.