Blue Sea E-Series Battery Switch On-Off With AFD

The Blue Sea E-Series Battery Switch On-Off With AFD is a heavy-duty marine battery disconnect engineered for anglers, cruisers, and serious boaters who demand reliable engine start and electrical isolation. Whether you're running a weekend fishing charter, leaving your boat unattended for weeks, or managing dual battery banks on a long offshore expedition, this switch delivers the control you need at a moment's notice. The AFD (Automatic Float Disconnect) feature prevents accidental drain when your batteries are idle—critical insurance against returning to a dead battery after extended layups.

Built with a robust 350-amp continuous rating, this switch handles inboard gasoline and diesel engines without compromise. The tin-plated copper studs provide maximum conductivity and superior corrosion resistance—essential when saltwater spray and moisture are constant threats in marine environments. The design accepts up to 4/0 AWG battery cable, ensuring proper gauge compatibility for high-amperage starter circuits and minimizing voltage drop during cold-weather starts or heavy load conditions. The E-Series architecture is proven across thousands of installations and backed by Blue Sea Systems' reputation for uncompromising quality.

Ideal for center console fishing boats, cabin cruisers, and dual-engine vessels, the Blue Sea E-Series Battery Switch integrates seamlessly into battery banks of any configuration. Installation is straightforward—mount near the battery, run your cable, and gain instant master power control and automatic anti-drain protection. At 1.3 lbs and compact form factor, it fits easily in tight engine compartments without sacrificing accessibility for future service or inspection.