Blue Sea Systems m-Series Mini Dual Circuit Battery Switch

The Blue Sea Systems m-Series Mini Dual Circuit Battery Switch simplifies multi-bank switching by controlling two isolated circuits from one switch, instead of needing two separate single-circuit switches side by side. It can be used to switch the positive and negative conductors together where that's required.

Key features

• Simultaneously switches two isolated battery banks or circuits
• 300A continuous per circuit, 500A intermittent (5 min)
• 900A cranking (30 sec), 32V DC maximum
• 3/8"-16 (M10) tin-plated copper studs, torque 120 in-lb (13.56 Nm)

This switch cannot combine the two banks together, which makes it the correct choice specifically when positive and negative conductors both need switching together, since the combine feature on the Plus version would make that particular use unsafe.

Both circuits switch together from the single knob, so plan the wiring so each circuit's positive and negative pair lands on the correct terminal set — a labeling mistake here is easy to make and harder to trace once the switch is buttoned up behind a panel.

Torque the terminal studs to 120 in-lb (13.56 Nm). This compact Mini switch handles two circuits in the same footprint as the single-circuit Mini models, saving panel space over installing two separate switches side by side while keeping the two circuits fully independent from each other. Because it manages two circuits from one knob, confirm during installation which terminal pair corresponds to which circuit before finishing the wiring, so the switch's labeled positions match the physical circuits correctly. A tidy, well-labeled installation makes future troubleshooting far faster than tracing unlabeled cables back through the boat.