Blue Sea Systems 7620 ML-Series 500A Automatic Charging Relay with Remote Switch

The Blue Sea Systems 7620 ML-Series Automatic Charging Relay (ACR) is a heavy-duty 500-amp magnetic latching relay designed to automatically manage charging and isolation for dual battery bank systems. This intelligent relay combines batteries during charging to share alternator output, then isolates banks during discharge or engine starting to prevent accidental drainage and protect sensitive electronics.

Magnetic Latching Technology:

The ML-Series uses bi-stable magnetic latching technology that draws minimal current (less than 40mA) while monitoring voltage, and only requires moderate current for brief moments when changing state. This efficient design reduces parasitic battery drain compared to traditional solenoid-based systems.

Key Features:

• 500-amp continuous rating with 700-amp intermittent capacity for high-demand applications
• Dual voltage sensing monitors both battery banks independently for intelligent charge management
• User-selectable Start Isolation or Engine Isolation modes protect sensitive electronics from voltage spikes
• Included Contura-style remote switch with ON/AUTO/OFF positions and LED indicators
• Emergency combine function allows manual battery combining for emergency starting
• Ignition protected (ISO 8846, SAE J1171) for safe installation in gasoline engine compartments
• Remote switch operation eliminates expensive heavy-gauge cable runs—requires only 20 AWG wire
• Compatible with Blue Sea Systems ML-RBS Remote Battery Switches and 9160 Paralleling Link Bus
• IP66 rated for protection against water and dust intrusion
• 3/8-inch terminal studs accommodate up to 4/0 AWG cable
• Backed by Blue Sea Systems lifetime warranty

Technical Specifications:

• Nominal voltage: 12V DC
• Operating current: 13mA monitoring, under 7.0A when changing state
• Live current switching capacity: 300A at 12V DC
• Combine voltage thresholds: 13.5V (30 sec), 13.0V (90 sec)
• Open voltage thresholds: 12.35V (10 sec), 12.75V (30 sec), 16.2V (high voltage protection)
• Weight: 2.04 lbs
• Certifications: CE marked, ISO 8846, SAE J1171, IP66

Ideal for marine applications with large house and engine battery banks, the ML-ACR simplifies installation while providing professional-grade battery management and protection. When paired with optional ML-RBS switches and paralleling link bus, it creates a complete push-button battery management subsystem.