My Account
Shopping Cart

Blue Sea Systems 9004EBSS e-Series On-Off Battery Switch with Alternator Field Disconnect

Manufacturer

Blue Sea Systems

<p>When electrical reliability can mean the difference between a successful voyage and a dangerous situation, marine professionals and enthusiasts turn to Blue Sea Systems. Founded in 1992, this American manufacturer has built a reputation for creating electrical components specifically engineered to withstand the unforgiving marine environment. Every product reflects a commitment to safety standards and real-world performance that has made Blue Sea Systems a leading name in marine and specialty vehicle electrical systems.</p> <h3>Engineering for the Marine Environment</h3> <p>Blue Sea Systems develops and manufactures dependable AC and DC electrical products for marine and specialized vehicle applications, designed in the USA and engineered to excel in challenging environments. The marine environment presents unique challenges—salt spray, constant vibration, temperature extremes, and moisture exposure—that can quickly degrade inferior electrical components. Blue Sea Systems addresses these challenges through careful material selection, rigorous testing protocols, and designs that prioritize both safety and serviceability. Their components are engineered for marine use and align with the intent of ABYC E-11: AC and DC Electrical Systems on Boats and relevant USCG electrical regulations.</p> <h3>Commitment to Safety Standards</h3> <p>Safety standards aren't just guidelines for Blue Sea Systems—they're fundamental to every product design. All Blue Sea Systems marine battery disconnect switches comply with the ABYC C-7 certification, demonstrating their commitment to meeting and exceeding industry safety requirements. The company maintains ABYC-certified employees across multiple departments, from engineering to technical support, ensuring deep expertise in marine electrical system design and installation standards.</p> <h3>Comprehensive Product Range</h3> <p>Blue Sea Systems offers an extensive catalog designed to address every aspect of marine electrical systems. Their <a href="/7262-blue-sea-systems-circuit-breakers-200260">circuit breakers</a> provide resettable overcurrent protection with trip-free designs and clear trip indication for quick diagnostics. For power management, their <a href="/7262-blue-sea-systems-battery-switches-manual-200149">battery switches</a> offer reliable methods for controlling battery banks and disconnecting loads during storage or emergencies, with ABYC C-7 compliance guaranteed.</p> <p>Monitoring system health is critical aboard any vessel, which is why their <a href="/7262-blue-sea-systems-battery-monitors-volt-meters-200146">battery monitors and volt meters</a> provide accurate real-time data to help operators make informed decisions about power usage and charging. The company's <a href="/7262-blue-sea-systems-terminal-blocks-bus-bars-201059">terminal blocks and bus bars</a> create organized, serviceable connection points that simplify installation and future modifications. For keeping batteries properly charged, Blue Sea Systems offers <a href="/7262-blue-sea-systems-battery-chargers-200141">battery chargers</a> engineered with features like automatic charging relay compatibility and proper charge profile management.</p> <h3>Built by Boaters, for Boaters</h3> <p>Blue Sea Systems was founded based on a commitment to create innovative high quality marine electrical products to improve the safety, simplicity, and reliability of boating, with employees who are active boaters applying their passion to designing, developing, and building products. This firsthand experience translates into practical features like modular layouts, standardized footprints, and installer-centric designs that streamline panel work and serviceability. The result is a product line that addresses real challenges faced on the water, backed by comprehensive technical documentation and support resources that help both professionals and DIY enthusiasts complete installations with confidence.</p>

Part Number

9004EBSS
06/01/2036 6:07 AM
Sale Price

$86.90

In Stock (10+)

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 Blue Sea Systems 9004EBSS is a heavy-duty e-Series battery switch designed for marine and RV electrical systems. This single-pole, single-throw switch provides reliable ON-OFF battery circuit control with integrated Alternator Field Disconnect (AFD) functionality to protect your charging system when switching battery banks.

Key Features:

  • Alternator Field Disconnect (AFD) terminal prevents alternator damage during battery bank switching
  • Rated for continuous duty at 300 Amps, with intermittent surge capacity up to 500 Amps
  • Robust stainless steel construction with corrosion-resistant materials for marine environments
  • Large contact surface area and low resistance design minimizes voltage drop and heat generation
  • Sealed switch mechanism protects against moisture and contaminants
  • Easy-to-read ON/OFF labeling with red locking safety cover prevents accidental operation
  • Accepts up to 5/16-inch battery cable terminals for secure, high-current connections

The e-Series line from Blue Sea Systems represents professional-grade switching technology with superior reliability and safety features. The AFD function is essential for protecting alternators in dual-battery or battery bank systems, automatically disconnecting the alternator field before interrupting battery circuit current. Ideal for boats, RVs, and commercial vehicles requiring dependable battery isolation and charging system protection.

Products specifications

Type

ON-OFF with AFD

Two thumbs up.

Easy and quick

parts were as ordered and received in less time than estimated. will continue using AUTOPLICITY

Tires were sent and arrived on time, just as described, and the price was great, completely satisfied with the product and service.

Product was competitively priced, as described, and arrived promptly.

Quick check-out. See about service after I get gen.

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