Overview

The Blue Sea Systems 5023 is an ST Blade battery terminal mount fuse block that adds four ATO/ATC fused circuits right at the battery. It mounts on a 3/8 in [M10] battery stud, works on DC systems up to 32V, and is rated for 100A total with up to 30A on each circuit.

This is a practical way to clean up accessory wiring near the battery and replace a cluster of separate in-line fuse holders with one protected distribution point. On board, that makes it easier to add and service a few dedicated feeds for electronics, pumps, stereo equipment, or lighting without taking up much space.

Key features

• Four independent ATO/ATC fuse positions for accessory branch circuits from one battery-side feed
• Direct battery terminal mounting with clearance for a 3/8 in [M10] stud
• 100A maximum per block and 30A maximum per circuit on systems up to 32V DC
• #8-32 screw terminals with captive star lock washers; screw terminal torque is 18 in-lb (2.03 Nm)
• Insulating cover helps reduce accidental contact and the block accepts small format circuit labels for circuit identification
• Ignition protected with the cover secured to SAE J1171 and ISO 8846

Compatibility and fit

Check the battery terminal layout before ordering. The block measures about 3.59 in long, 1.73 in wide, and 1.28 in high, so it fits best where there is enough clearance around the battery post and cable connections. It suits 12V and 24V systems and is better matched to accessory circuits than to single high-draw loads that need more than 30A on one branch.

Installation and use

Because it mounts directly at the battery, this fuse block works well when you want a short, tidy takeoff point for a few added circuits. Each outgoing circuit lands on its own screw terminal, and the label area helps later when you are tracing a chartplotter, bilge pump, stereo, or cabin light feed. It is a good match for smaller boats, refits, and auxiliary battery installations where four protected circuits are enough.

What's included

• ST Blade battery terminal mount fuse block
• Insulating cover
• One 15A ATO/ATC fuse
• Four nylon insulated ring terminals