Blue Sea Systems ML-RBS Remote Battery Switch, 500A, Manual Control, Auto-Release

Overview

The Blue Sea Systems ML-RBS is an auto-releasing remote battery switch with manual control for 12V DC or 24V DC marine battery systems. It gives high-current battery switching from a remote helm, panel, or electrical control location, while the manual override knob on the switch still allows local operation when power is unavailable.

This ML-Series switch is rated for 500A continuous service and 700A intermittent service for 5 minutes, with live current switching up to 300A at 12V DC. The auto-releasing coil is suited to installations where a normally open relay behavior is needed, and it can be controlled with SPST or SPDT switching depending on the vessel wiring layout.

Power cable connections are made on 3/8-16 tin-plated copper studs with 7/8 in stud length, giving room for properly sized cable lugs in high-amperage battery runs. Silver alloy contacts, label recesses, and an LED output for remote switch-state indication make it a practical fit for battery banks, engine starting circuits, and main DC distribution layouts on cruising, fishing, and work boats.

Key features

• 500A continuous rating for high-current battery switching in marine DC systems.
• 700A intermittent rating for 5 minutes, with live current switching up to 300A at 12V DC.
• Auto-releasing coil function for control layouts that use SPST or SPDT switching.
• Manual override knob allows local control with or without power and supports a locked-off service position.
• 3/8-16 tin-plated copper studs with 7/8 in length accept large battery cable terminals.
• Silver alloy contacts support switching under load in demanding onboard electrical systems.
• LED output can be used for remote switch-state indication when paired with an optional LED.
• Control circuit options cover 12V DC and 24V DC systems, with either tinned wire or Deutsch DTM / Amphenol ATM connection styles.

Variants

This ML-RBS battery switch is offered in four configurations based on control circuit voltage and control circuit connection style.

The 12V DC versions use a 10.1 to 16.5V DC control circuit range, while the 24V DC versions use a 20.2 to 32.9V DC control circuit range. All four variants share the ML-RBS auto-releasing format, 500A continuous current rating, manual control, and 3/8-16 main terminal studs.

• 7713: 12V DC nominal voltage with tinned wire control circuit connection. This version suits conventional hardwired control circuits on 12V battery systems.
• 7713100: 12V DC nominal voltage with Deutsch DTM / Amphenol ATM control circuit connection. This version fits 12V systems where a connectorized control harness is preferred for service access or cleaner panel wiring.
• 7717: 24V DC nominal voltage with tinned wire control circuit connection. This version is intended for 24V control circuits that use direct hardwired leads.
• 7717100: 24V DC nominal voltage with Deutsch DTM / Amphenol ATM control circuit connection. This version matches 24V installations that use connectorized control wiring.

Installation and setup

Install the switch close enough to the battery bank or main distribution point to keep high-current cable runs practical, while leaving access to the manual control knob and terminal hardware. The main terminal studs use a 140 in-lb torque value, and the cable size needed to meet the published ratings is 2x 4/0.

The control side should be matched to the vessel voltage before installation. The 12V variants are for 12V DC control circuits, and the 24V variants are for 24V DC control circuits. The tinned wire versions are straightforward for direct wiring, while the Deutsch DTM / Amphenol ATM versions help when a removable harness connection is part of the electrical layout.

Use cases on board

This switch is a strong match for boats where the battery switch needs to be operated from a helm, nav station, electrical panel, or other remote location without giving up manual access at the switch itself. It is useful on larger DC systems, multi-bank battery installations, and vessels where battery isolation needs to be clear, repeatable, and serviceable.

The locked-off manual position is especially useful during maintenance, troubleshooting, or dockside service work, where a physical local control point helps prevent accidental energizing of the circuit.

What’s included

• ML-RBS Remote Battery Switch with Manual Control Auto-Release
• SPDT Remote Control Contura Switch - ON-ON