The Advantages of Battery-Mounted Fusing

The practice of mounting fuses directly onto the battery as a starter protector fuse is becoming more prevalent in high-amp truck and vehicle applications, and with good reason: Battery-mounted fusing offers a variety of advantages, making it a simple, safe, and accessible  alternative to fuse box wiring that requires a two-bolt connection near or inside the harness. 

Safety at the Source

Fuses placed directly on the battery provide immediate protection to critical components, preventing overloads at main branch circuits, power distribution modules, and auxiliary systems. By containing potential overcurrent situations right at the source –the battery—the risk of electrical fires or damage to other components is minimized, enhancing overall vehicle safety. The time current characteristics of the leading battery-mount fuses are similar to the well-known Mega fuse design and can be used as full wire protection up to 250 amps. 

Efficiency and Simplicity Gains

Incorporating fuses directly onto the battery can simplify circuit design and installation, especially in complex electrical systems found in modern vehicles and work trucks.

Since battery-mounted fuses are placed close to the power source, there’s less wiring needed to connect them to other components, reducing potential points of failure and minimizing voltage drops. 

Finally, being mounted on the battery makes these fuses easily accessible for inspection or replacement, simplifying maintenance and troubleshooting. 

Examples of Battery-Mounted Fuses 

Battery-mounted fuses that are designed to fit directly to the battery post or stud include industry-leading products such as Eaton’s MRBF fuses and Littelfuse’s ZCASE® MEGA® fuses. These fuses are very compact and can be connected to either a battery post or a busbar.

Fuse Holders

Stud-mountable fuse holders can also serve as a means of mounting a fuse to the battery post. For example, up to three fuses can be mounted on a single battery post using Littelfuse’s SMZ series fuse holders (shown at right). The busbar design allows three fuse holders to be stacked onto a single battery terminal. Learn more about fuse holder options in the article The Benefits of Battery-Mounted Fuse Holders. 

Not Just for Batteries

In addition to connecting to batteries, stud-mountable fuses and fuse holders can be mounted in other parts of the vehicle such as on power distribution modules and on many common types of switches and relays. As such they are a flexible solution for protecting a variety of components. Typically, these fuses and fuse holders will be specified to mount on an M6 or M8 bolt or stud.

Cost-Compatibility

While the initial cost of battery-mounted fuses might be slightly higher compared to traditional bolt-down fuses, you’ll often come out ahead in terms of efficiency and ease of use. The overall cost-effectiveness of the system can also be significant due to reduced wire, simplified maintenance, and improved system reliability. 

Insulated Nuts

Battery-mounted fuses are made with specially insulated nuts to ensure safety and performance. Be sure to use only the manufacturer-specified part when replacing a lost or damaged nut on a battery-mounted fuse. 

Conclusion

With all the benefits that come with battery-mounted fuses and fuse holders, they are an option you want to keep in mind when it comes to protecting complex, high amp circuits in your specialty vehicle or work truck. Learn more about battery-mounted fuses and fuse holders available at Waytek.