Balmar 604-120-K6 120 Amp 12V 6-Series Dual Foot Saddle Mount Marine Alternator with K6 Serpentine Pulley

The Balmar 604-120-K6 is a high-output marine alternator from Balmar's popular 6-Series lineup, delivering 120 amps at 12 volts in a compact, small-case design. It features a 4-inch saddle (dual foot) mount in the J-180 style, making it a direct-fit replacement for many Caterpillar, Cummins, Detroit Diesel, and John Deere marine diesel engines.

Balmar's patented Smart Ready® Technology gives this alternator exceptional flexibility — it can operate with its built-in internal regulator at a fixed 14.1-volt charge rate, or it can be paired with an external multi-stage voltage regulator such as the Balmar ARS-5 or Max Charge for optimized, intelligent battery charging. This makes it an ideal upgrade for vessels with larger deep-cycle or lithium battery banks, or those with less frequent engine duty cycles such as sailboats.

Key Features:

• Output: 120 Amps at 12 Volts
• Mount Style: 4-inch Saddle Mount (Dual Foot) — J-180-Style
• Pulley: K6 Serpentine Pulley
• Grounding: Isolated Ground (dedicated ground terminal, case isolated)
• Smart Ready® Technology: Compatible with internal or external multi-stage regulation
• Internal Voltage Regulation: Fixed 14.1V single-stage (usable as a standalone or backup regulator)
• Cooling: Dual fan with high-airflow frame
• Cut-In RPM / Max RPM: 1,320 RPM / 15,000 RPM
• Max Operating Temperature: 225°F (108°C)
• Stator Output: 12-pulse AC/stator output with pigtail plug
• Certifications: USCG Title 33, ISO J1187, SAE 8846, CE
• Typical Engine Applications: Caterpillar, Cummins, Detroit Diesel, and John Deere

The 604-120-K6 can be purchased as a standalone alternator or as part of a complete charging kit that includes the alternator, regulator, and two temperature sensors. For 24-volt systems, dual-alternator setups, or twin-engine configurations, a Max Charge Regulator Kit is required. Balmar backs this alternator with a one-year limited warranty.