About this product

The Blue Sea Systems m-Series Mini On-Off Battery Switch with Knob is a compact single-circuit battery switch for controlling one battery or battery bank feeding one load group. It has two positions, ON and OFF, with a maximum voltage rating of 48V DC, a 300A continuous rating, a 500A intermittent rating for 5 minutes, and a 900A starting rating for 30 seconds.

This switch suits small boat battery isolation, outboard installations, and gasoline or diesel engine circuits where a simple manual disconnect is needed near the battery, helm, or electrical panel. The IP66 rating helps it handle spray and washdown exposure, while ignition protection supports installation aboard gasoline-powered boats when fitted correctly.

The m-Series case supports surface, front panel, or rear panel mounting, which gives installers more flexibility in tight lockers and console spaces. Rear contacts are protected by an isolating cover with snap-on sections, and the 3/8"-16 M10 tinned copper terminal studs are sized for heavy battery cables up to the listed 4/0 AWG rating requirement.

Key Features

• Single Circuit ON-OFF switching for one battery or battery bank feeding one load group.
• Rated for 48V DC maximum, 300A continuous, 500A intermittent for 5 minutes, and 900A starting for 30 seconds.
• IP66 rating for protection against powerful water jets in exposed marine areas.
• Ignition protected for use aboard gasoline-powered boats when installed according to the vessel electrical plan.
• Mounts on the surface, through the front of a panel, or from the rear of a panel.
• 3/8"-16 M10 tinned copper terminal studs support secure battery cable connections and resist corrosion at the contact points.
• Accepts #10 mounting screws and provides 1.12 in of cable clearance for 4/0 AWG cable routing.
• No battery combine function and no alternator field disconnect, keeping the operation simple for a basic ON-OFF battery isolation circuit.
• Meets UL 1500 and SAE J1171 external ignition protection requirements
• Ingress Protection IP66 - dustproof/protected against heavy seas and jets of water from all directions
• CE marked, ISO 8845, UL Listed - UL 1107 electric power switches
• Meets American Boat and Yacht Council (ABYC) requirements for battery switches