Overview

The Hella Marine 100/150 Amp Battery Master Switch is a keyed ON/OFF disconnect switch used to isolate a battery bank or other high-current feed on board.

It installs in either the positive or negative main lead and connects via M10 screw terminals for heavy-gauge ring lugs. The housing is rated IPX4 for splash exposure, which fits sheltered mounting spots where the switch is not taking direct washdowns.

Continuous rating depends on the configuration (100A or 150A). Short-duration cranking capability is specified for high inrush loads (10 seconds), up to 5000A at 12V or 2500A at 24V on some versions, and up to 1000A at 12V or 500A at 24V on others.

Key features

• Keyed ON/OFF disconnect for a single battery circuit or high-current feed
• Key can be removed in the OFF position, with the circuit open, to prevent unintended energizing
• Suitable for switching either the positive or negative main lead
• M10 screw terminals for common marine battery-cable lugs
• IPX4 splash protection for protected on-board locations
• Available in 100A and 150A continuous ratings depending on configuration

Variants

This switch family is offered in multiple configurations. The part number identifies the continuous current rating and the voltage range listed for that version.

These versions share the same keyed ON/OFF style and M10 terminal connection, so the main differences are the electrical ratings shown below.

• 002843011: Amperage 100 Amps, Voltage 24V DC. Listed for 24V DC systems where a keyed main disconnect is required.
• 001559001: Amperage 100 Amps, Voltage 10-30V DC. The 10-30V DC range covers common 12V and 24V battery systems.
• 002843051: Amperage 150 Amps, Voltage 10-30V DC. Higher continuous current rating for circuits carrying heavier loads within a 12V or 24V system.

Installation and setup

Mount the switch where it can be reached quickly and where the rear terminals stay protected from loose gear, dripping water, and accidental contact. Leave room for cable bends and for removing the key.

Use ring lugs sized for M10 studs and support the cables so vibration is not carried by the terminals. After wiring, confirm that OFF fully isolates the intended circuit and that the key only comes out with the switch open.

Compatibility and fit

This is a single-circuit battery master switch, so it disconnects one circuit at a time. Boats with separate start and house banks commonly use one switch per bank, or one per major feed that needs isolation.

Match the continuous amp rating to the expected draw on that circuit, and plan the mounting location around the IPX4 splash rating, with added shielding if the area sees direct spray.

Use on board

Common installs include a main house-bank disconnect near the batteries, a starting circuit shutoff, or a dedicated feed for a windlass or other high-current accessory that you want isolated during storage or service.

This is a good fit for boats that want a simple keyed shutoff without multi-bank selection functions.