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

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.