My Account
Shopping Cart

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

Manufacturer

Balmar

<h3>About Balmar: Marine DC Power Since 1981</h3><p>Since its founding in 1981, <strong>Balmar</strong> has built a reputation as one of the most trusted names in marine DC power. For over four decades, the company has focused exclusively on helping sailors and power boaters solve one of the most persistent challenges on the water: keeping batteries charged reliably and efficiently. That singular focus has made Balmar the go-to choice for serious mariners who demand more from their electrical systems.</p><h3>Innovative Alternator Technology</h3><p>Balmar's greatest claim to fame is its lineup of <a href="/12782-balmar-alternators-200087">marine alternators</a> — widely regarded as the highest-output and most dependable alternators available in the recreational marine market. What sets Balmar apart is not just raw output, but smart engineering. Their patented <strong>Smart Ready&reg; Alternator</strong> technology allows the alternator to communicate directly with an external regulator, enabling precise, multi-stage charging profiles that protect batteries and extend their service life. Whether you're running a modest weekend sailboat or a fully outfitted bluewater passage-maker loaded with electronics, Balmar offers an <a href="/12782-balmar-alternator-2412">alternator</a> sized and engineered for the task.</p><p>Marine environments are uniquely demanding — salt air, vibration, and the need for long, uninterrupted charging cycles put far more stress on electrical components than typical automotive applications. Balmar designs its alternators specifically for these conditions, with robust construction and thermal management that keeps performance consistent even during extended motoring passages.</p><h3>Battery Monitors &amp; Charging System Management</h3><p>A high-output alternator is only part of the equation. Knowing the true state of your battery bank is equally critical, which is why Balmar also produces a respected line of <a href="/12782-balmar-battery-monitors-volt-meters-200146">battery monitors and volt meters</a>. These instruments give mariners accurate, real-time insight into battery voltage, state of charge, and current flow — the kind of data that prevents being stranded at anchor with a dead house bank. Balmar's monitoring products are designed to integrate seamlessly with their charging ecosystem, giving you a complete picture of your DC system's health at a glance.</p><h3>Expert Support &amp; a Legacy of Trust</h3><p>Beyond the products themselves, Balmar has long been recognized for its exceptional technical support. Marine electrical systems can be complex, and Balmar's knowledgeable team has a well-earned reputation for helping customers spec the right components and troubleshoot installations. That combination of innovative hardware and genuine expertise is a big reason why Balmar has remained a privately held, customer-focused company for over 40 years — and why the brand continues to be found aboard everything from coastal cruisers to offshore racing yachts.</p>

Part Number

604-120-K6
09/12/2036 12:25 PM
Sale Price

$749.74

2 left at this price

delivery box

Usually delivered within 2 days

free shipping

FREE SHIPPING

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

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.

Products specifications

Dimensions

5.35" (136 mm) Diameter x 5.08" (129 mm) Length x 7.5" (190 mm) Height

Mount Type

Dual Foot 4"

Type

Alternator

Voltage

12 Volts DC

Outputs

1 Output

ISO Approved

USCG Title 33ISOSAECE Compliant

Pulley Groove Type

Serpentine Groove

Pulley Outside Diameter

2.45 Inches

Rated Output Power - 2000 RPM Hot

60 Amps

Rated Output Power - 6000 RPM Hot

109 Amps

Warranty Details

One Year Limited Warranty against Defects in Material or Workmanship

i like it

Great GFB BOV's and fast shipping!

Your system showed delivery three days before it was delivered. Caused of concern.

Fast great service

Surprised how through the shopping experience was and my tire was delivered extremely fast will definitely be back for future purchases:)

Very good,

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy