Blue Sea 350A Red e-Series On Off Battery Switch

High-current battery isolation for safer marine power systems

The Blue Sea e-Series ON/OFF battery switch is designed to give you confident control over a single battery feeding a single load group—ideal when you want a clear, manual way to isolate power for servicing, storage, or fault finding. In marine electrical systems, a dedicated battery isolator helps reduce the risk of accidental short circuits, parasitic drain, and unintended battery discharge when the vessel is unattended.

Built for demanding marine environments, this switch suits common Australian boating and 4WD auxiliary power setups where reliability and straightforward operation matter. Use it to quickly cut power to a house circuit, isolate a battery before maintenance, or create a simple, easy-to-understand system layout that technicians and owners can diagnose without guesswork.

Designed for marine installation requirements

This model is ignition protected, making it appropriate for installation on gasoline-powered boats where equipment may be exposed to fuel vapours. That extra layer of safety consideration can be important when upgrading older wiring or bringing a DIY install closer to accepted marine practices.

The e-Series housing also supports flexible installation, with a case design that allows either surface mounting or rear panel mounting. That means you can achieve a cleaner helm or switch panel finish, or mount it where cable routing is most practical—helpful when working with tight compartments and heavier battery cabling.

When this ON/OFF switch is the right choice

If your system is a single battery supplying a single circuit group, an ON/OFF battery switch is often the most direct option. It’s well suited to:

• Small to mid-size boats running a dedicated house battery
• Runabouts and fishing boats needing a simple battery cut-off for storage
• Auxiliary battery isolation in 4WDs, camper trailers, and portable power bays
• Workshop or test-bench DC systems where quick isolation improves safety during changes

Key features

• Single-circuit ON/OFF control to isolate one battery from one load group
• Ignition protected for use on gasoline-powered boats where vapour safety is a consideration
• Flexible mounting options with surface or rear panel mounting to suit your layout
• High-current capability suited to demanding DC loads common in marine and automotive auxiliary systems
• Clear manual isolation to support maintenance, storage, and fault diagnosis workflows

Why it helps in real-world installations

A robust battery switch can reduce common electrical issues such as slow battery drain from standby loads, hard-to-trace intermittent faults, and unsafe service conditions where circuits remain energised. By adding a dedicated isolation point, you can simplify troubleshooting and help protect sensitive electronics during maintenance or system changes.

For installers and DIY owners alike, the value is in predictability: a clear OFF position when you need the system de-energised, and a direct ON position when you’re ready to run. Pair it with appropriately sized cabling, correct terminal torque, and suitable circuit protection to support long-term reliability in harsh marine conditions.