Blue Sea 3003 HD-Series Battery Switch with AFD

Description

The Blue Sea 3003 HD-Series Battery Switch Selector with Alternator Field Disconnect is designed for larger dual-bank marine battery systems that require substantial current capacity and a traditional selector function. Its 500A continuous rating and ability to accept 4/0 battery cables make it suitable for high-output engine starting and heavy DC loads.

The selector allows the operator to choose between battery banks while the alternator field disconnect function helps protect the charging system during switching. Tin-plated M12 copper studs provide high conductivity and corrosion resistance, and the extended stud length gives installers room for multiple cable terminals where required.

The switch is ignition protected for appropriate gasoline-powered boat installations and meets ABYC battery-switch requirements. Tactile knob textures help identify switch position by feel, and the housing can be surface mounted or rear-panel mounted. Blue Sea also designed the footprint to fit common Perko and Guest low-amperage battery-switch hole patterns, simplifying many replacement installations. For larger dual-bank systems, the 3003 combines familiar selector operation with heavy-duty current handling and alternator protection. Worth comparing against our other battery switches.