---
product_id: 3836489
title: "5191"
brand: "blue sea systems"
price: "€ 43.17"
currency: EUR
in_stock: null
reviews_count: 8
category: "Blue Sea Systems"
url: https://www.desertcart.pt/products/3836489-5191
store_origin: PT
region: Portugal
---

# 300A max current Weatherproof for harsh marine use Universal fit, easy install 5191

**Brand:** blue sea systems
**Price:** € 43.17
**Availability:** ❌ Out of Stock

## Summary

> ⚡ Stay powered, stay protected — fuse your circuits like a pro!

## Quick Answers

- **What is this?** 5191 by blue sea systems
- **How much does it cost?** € 43.17 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.pt](https://www.desertcart.pt/products/3836489-5191)

## Best For

- blue sea systems enthusiasts

## Why This Product

- Trusted blue sea systems brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Safety First:** Insulating cap prevents accidental shorts, ensuring peace of mind
- • **Ignition Ready:** Compatible with MRBF fuses for ignition protection on marine and vehicle systems
- • **Powerhouse Protection:** Handles up to 300 amps for your high-demand circuits
- • **Built for the Elements:** Weatherproof design keeps your system safe in open-cockpit and harsh environments
- • **Effortless Integration:** Universal fit and corrosion-resistant materials make installation a breeze

## Overview

The Blue Sea Systems 5191 Fuse Block Terminal is a compact, marine-grade fuse block designed to protect DC circuits up to 300 amps. Weatherproof and corrosion-resistant, it’s perfect for boats and vehicles requiring reliable, high-capacity overcurrent protection. Featuring universal fit and an insulating cap for safety, it supports 30A to 300A MRBF fuses (sold separately) and is ignition protected when paired with MRBF fuses.

## Description

The Blue Sea Systems 5191 Fuse Block Terminal (30–300 AMP) is a rugged marine‑grade DC fuse block that accepts 30–300 A MRBF battery terminal fuses to protect multiple circuits in boat or vehicle electrical systems. Designed for easy installation with corrosion‑resistant materials and clear amperage labeling, it provides organized, high‑capacity overcurrent protection for large battery banks and accessory loads.

Review: Blue sea fuse blocks - I bought 2 of these and as I thought, they are very well made and I'm sure will work for me very well.
Review: Excellent quality - I used this as well as several other blue sea parts on a build. The blue sea parts are excellent quality, easy to work with, and well worth the investment.

## Features

- Voltage Max Operating: 58V DC, Amps Max Operating: 300A per block, Terminal Fuses Avail.: 30A-300A, Terminal Stud Size: 5/16"-18 (8mm), Mounting Hole Size: 10 (5mm)3/8"
- Compact, high-amp fuse—appropriate for DC Main, inverter, windlass, and bow thruster circuit protection
- Weatherproof – suitable for small open-cockpit boats and other harsh environments
- Insulating cap prevents accidental shorts
- Ignition protected when used with MRBF fuses
- Fuses sold separately
- Fit type: Universal Fit

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0019ZBTV4 |
| Best Sellers Rank | #9,007 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #2 in Fuse Blocks (Tools & Home Improvement) |
| Brand Name | Blue Sea Systems |
| Color | Single Fuse |
| Connector Type | Screw |
| Current Rating | 300 Amps |
| Customer Reviews | 4.6 out of 5 stars 929 Reviews |
| Gauge | 1.0 |
| Global Trade Identification Number | 00632085051914 |
| Included Components | Blue Sea Systems 5191-BSS MRBF Terminal Fuse Block - 30A-300A |
| Item Dimensions W x H | 2.5"W x 2"H |
| Item Type Name | Blue Sea Systems 5191-BSS MRBF Terminal Fuse Block - 30A-300A |
| Item Weight | 1.6 ounces |
| Manufacturer | Blue Sea Systems |
| Material | Plastic |
| Material Type | Plastic |
| Model | 5191 |
| Mounting Type | hole mount |
| Number Of Contacts | 1 |
| Number Of Poles | 1 |
| Number of Positions | 1 |
| Part Number | 5191 |
| Specification Met | Sea |
| UPC | 632085051914 |
| Unit Count | 1.0 Count |
| Voltage | 58 Volts |

## Product Details

- **Brand:** Blue Sea Systems
- **Color:** Single Fuse
- **Connector Type:** Screw
- **Current Rating:** 300 Amps
- **Gauge:** 1.0
- **Material:** Plastic
- **Mounting Type:** hole mount
- **Number Of Contacts:** 1
- **Number Of Poles:** 1
- **Voltage:** 58 Volts

## Images

![5191 - Image 1](https://m.media-amazon.com/images/I/61vPpZ-72JL.jpg)

## Available Options

This product comes in different **Color, Style** options.

## Questions & Answers

**Q: Does this item come with the fuse terminal included? If so, how do I specify the amperage**
A: I just ordered three of these - they each came with a 300A fuse.  I was not expecting fuses to be included, so I had ordered them separately.  If this is not a shipping/packaging mistake, it would be nice if the seller gave the option to choose a fuse size.  While I can use a 300A on one of the terminals, I needed smaller ones for the others.  I didn't buy them weeks ago because of the relatively high price of these fuses (typically ~$15 each).  They were on sale for $10, so I got them now.

**Q: I have a new 100ah 12v lifepo battery. what fuse size do i need to go with this?**
A: At solavanbuild, I use 150 amp fuses with 1/0 AWG battery cables in most of my installs.

**Q: I'm thinking of running a charge/power wire of the alternator to a trailer battery.  Would it be OK to use this off the charge lead on the alternator?**
A: I would recommend an automatic Charing Relay  ACR. Blue sea makes great ones. I use their Mini-ACR because my boat alternator is less than 65A.  Their standard handles up to 300A.  Remember regardless, you will need TWO of these fuses, one at each battery. If your alternator puts out 60A then 75A fuses, if it puts out 100A than 130-150A fuses.

**Q: Can I use this as a bus bar (without a fuse), just to extend a 5/16 battery terminal. Thank you**
A: No you can't.. The stud is insulated from the block.. And don't grind it down. As they are meant for fuses to complete the circuit. Just buy a battery post if you need that...

## Customer Reviews

### ⭐⭐⭐⭐⭐ Blue sea fuse blocks
*by T***S on January 25, 2026*

I bought 2 of these and as I thought, they are very well made and I'm sure will work for me very well.

### ⭐⭐⭐⭐⭐ Excellent quality
*by N***L on March 14, 2026*

I used this as well as several other blue sea parts on a build. The blue sea parts are excellent quality, easy to work with, and well worth the investment.

### ⭐⭐⭐⭐⭐ Expanding Lynx Distributor Capacity with a Key Addition
*by V***S on October 20, 2023*

The Blue Sea Systems 5191 Fuse Block Terminal has been nothing short of a revelation for my power management setup. I invested in this brilliant solution to seamlessly integrate my Dometic RTX2000 air conditioner into my Lynx distributor by Victron. The challenge with the Lynx distributor was its limited available slots, necessitating the addition of another Lynx—an expensive and space-consuming proposition. The Blue Sea Systems fuse block terminal provided an elegant and straightforward solution. By attaching it to the end of the Lynx and securely fastening it with a simple bolt-down mechanism, I was able to connect the air conditioner to the Victron system. This small yet critical addition allowed me to not only connect the air conditioner but also monitor its current, draw, and amperage. In the past, the air conditioner was directly linked to the battery, leaving me guessing about its power consumption, which was far from ideal. It's essential to note that when installing the Blue Sea Systems 5191 Fuse Block Terminal, make sure you don't over-tighten the fasteners. Refer to the manufacturer's torque specifications to ensure a secure yet safe installation. In a nutshell, the Blue Sea Systems 5191 Fuse Block Terminal is a must-have addition for anyone aiming to optimize their power management system. It's a versatile, user-friendly solution that resolves common power distribution challenges. I wholeheartedly recommend this product to fellow enthusiasts who wish to take the guesswork out of power monitoring and improve energy efficiency. It's a true game-changer, delivering on its promises and ensuring a more streamlined and efficient power setup, with a vital caution for installation.

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---

*Product available on Desertcart Portugal*
*Store origin: PT*
*Last updated: 2026-04-01*