Blue Sea Systems m-Series Mini Battery Switch with Key, Single Circuit ON-OFF, 48V DC, 300A Continuous

Overview

The Blue Sea Systems m-Series Mini Battery Switch is a single-circuit ON-OFF battery switch with a removable key for isolating one battery from one load group on a boat. It is rated for up to 48V DC, with a 300A continuous rating, 500A intermittent rating for 5 minutes, and 900A starting rating for 30 seconds.

This switch is a practical fit for small craft, center consoles, runabouts, sailboats, and other marine electrical systems where a clear battery disconnect point is needed near the battery, helm, or distribution area. The keyed control helps prevent accidental operation and can be removed when the boat is secured.

Key features

• Single Circuit ON-OFF switching connects or isolates one battery from one load group.
• Rated for 48V DC systems, with 300A continuous current capacity for common marine battery loads.
• Intermittent rating of 500A for 5 minutes and starting rating of 900A for 30 seconds for engine starting loads.
• Ignition protected for installation aboard gasoline powered boats.
• Case supports surface mounting, front-panel mounting, or rear-panel mounting for flexible placement.
• Isolating rear cover with snap-on sections helps protect the rear contacts after installation.
• 3/8"-16 M10 tinned copper terminal studs support high-current battery cable connections.
• Mounting holes accept #10 screws, giving installers a common fastening size for panels and bulkheads.

Variants

This m-Series Mini Battery Switch is offered in two color configurations. Both variants use the same single-circuit ON-OFF key switch format, while the visible key and switch color change to match the installation style.

The electrical ratings, switch positions, mounting approach, and terminal stud format remain consistent across these two versions.

• 6005: Red. This version gives the battery disconnect a traditional red marine battery-switch look that stands out clearly near batteries, helm panels, or service areas.
• 6005200: Black. This version has a lower-contrast appearance for panels or compartments where a black control face better matches surrounding hardware.

Installation and fit

The compact m-Series case can be mounted on the surface of a panel, through the front of a panel, or from the rear, which helps when replacing an existing switch or laying out a new battery control area. Allow enough clearance behind the switch for battery cables and ring terminals, especially when using large conductors.

The terminal studs are sized for 3/8" and M10 ring terminals, with cable clearance for 4/0 AWG cable. Terminal stud torque is 120 in-lb, so final tightening should be done with the correct tool rather than by feel alone.

Use on board

This switch suits boats that need a straightforward manual battery shutoff for a single battery feed, such as small engine-start circuits, electronics load groups, or house distribution feeds that need to be isolated when the boat is stored. It is also useful where a removable key is preferred for extra control over who can energize the circuit.

Because the switch is ignition protected, it can be used in gasoline boat installations where electrical equipment may be located near fuel vapors, provided the overall installation follows marine electrical practices and the connected cable size matches the system load.