Blue Sea 11003 HD-Series Battery Switch with AFD

Description

The Blue Sea 11003 HD-Series Battery Switch with Alternator Field Disconnect is built for high-current marine battery systems that need a heavy-duty main switch and protection for the alternator during switching. Its 500A continuous rating makes it suitable for larger engines and substantial DC systems where smaller recreational battery switches may not provide enough capacity.

The switch accepts two 4/0 battery cables and uses M12 tin-plated copper studs for high conductivity and corrosion resistance. The extended stud length accommodates multiple cable terminals, while tactile textures on the knob allow the operator to identify switch position by feel. The housing supports both surface mounting and rear-panel mounting for installation flexibility.

Ignition-protected construction allows use in appropriate gasoline-powered boat installations, and the switch meets ABYC requirements for marine battery switches. Blue Sea rates the unit for very high short-duration cranking current in addition to its continuous load capability. For larger marine battery systems that need a robust manual disconnect with alternator field protection, the 11003 provides high-current switching in a durable HD-Series format. Find more in our battery switches.