Blue Sea Systems m-Series Mini Dual Circuit Plus Battery Switch, 32V DC, 300A, 3 Position

Overview

The Blue Sea Systems m-Series Mini Dual Circuit Plus is a 3-position marine battery switch for two isolated battery banks, with a combine function that can connect both banks to all loads when needed. It is rated for 32V DC systems, 300A continuous current, 450A for 5 minutes, and 675A starting current for 30 seconds per circuit.

This switch is a practical fit for boats with separate start and house battery banks where a single rotary control is preferred over multiple switches. In normal use, it switches both battery banks at the same time while keeping them isolated. When the combine position is selected, both banks are connected so available battery capacity can support starting or onboard loads.

The m-Series Mini format keeps the switch compact while still using 3/8 inch 16 terminal studs and tinned copper stud material. It carries IP66 and ignition-protected ratings, which makes it suitable for exposed marine electrical areas and for installation on gasoline-powered boats when installed correctly.

Key features

• Dual Circuit Plus switching handles two isolated battery banks and includes a battery combine position for shared load support.
• Make-before-break contact action helps maintain power while moving between battery switch positions.
• 32V DC maximum voltage rating supports common 12V and 24V marine DC battery systems.
• 300A continuous rating, 450A intermittent rating for 5 minutes, and 675A starting rating for 30 seconds per circuit suit many small to mid-size boat battery installations.
• 3/8 inch 16 terminal studs accept M10 ring terminals, with cable clearance for 4/0 AWG cable.
• Tinned copper studs help maintain conductivity in a marine electrical environment.
• Mounting holes accept #10 screws for secure installation on a battery switch panel or electrical board.
• IP66, ignition protected, ISO 8846, SAE J1171, UL 1107, UL 1500, and CE ratings support use in demanding marine installations.

Variants

This product is offered in two color configurations with the same m-Series Mini Dual Circuit Plus switch function.

The color is the visible difference between the variants. The switching type, 3-position layout, battery combine function, 32V DC rating, terminal stud size, cable clearance, and listed current ratings are consistent across the red and black versions.

• 6011, color red. The red face is easy to associate with a main battery disconnect or emergency battery control location on many marine DC panels.
• 6011200, color black. The black face gives the switch a lower-profile look for darker helm panels, equipment boards, or battery compartments where a less prominent control is preferred.

Installation and setup

Install this switch where the operator can reach it quickly and where the rear terminals are protected from accidental contact. The terminal studs require 120 in-lb of torque, and cable sizing should match the current rating and the length of the run. For installations using the full switch rating, 4/0 AWG cable is specified.

This switch does not include alternator field disconnect, so the charging system layout should be checked before replacing a different switch type. It also should not be used to switch positive and negative conductors together because the combine function is part of the Dual Circuit Plus design.

Compatibility and fit

The switch is suited to marine battery systems with two battery inputs, such as a start bank and a house bank. It is commonly used on cruising boats, fishing boats, and small workboats where separate battery banks need simple manual control with a clear combine option.

Before installation, confirm the vessel voltage, maximum current demand, cable gauge, ring terminal size, available panel space, and access behind the mounting location. A proper installation helps reduce voltage drop, heat at the terminals, and service issues caused by loose or undersized battery cables.