Fuses are a vital piece of safety equipment in any electrical system. Fuses protect the wire from an overcurrent event such as an electrical short or from trying to push too much power through too small of a wire. This blog post will teach you what type of fuse you need for your DIY camper electrical install.
Cheap vs Expensive Fuses
In the past, I’ve recommended very inexpensive fuses. They worked for a while and many people had good luck with them. Recently (since February 2020), both myself and the tech support team at Battle Born Batteries who I work closely with have seen an increasing number of quality control issues on these non-name-brand fuses that are so common on Amazon. These problems revolve largely around the fuse getting too hot under normal use. This would cause the fuse holder to melt, loosen, and cause the system to stop working.
So… if you wish to save some money and test your luck with these inexpensive fuses and fuse holders; that is your prerogative; but I can no longer recommend “no-name” fuses and fuse holders on EXPLORIST.life. So, the following list will include only fuses and holders from Blue Sea, Littelfuse, Bussman, Eaton, Spartan Power or similar that have, at least some kind of testing agency certification or code compliancy recognition (UL, ABYC, ROhS, etc).
How Big of a Fuse do I Need for [My Device]
This blog post is more about the various TYPES of fuses and not necessarily how to choose the sizes. If you want a more in-depth blog post & video that will teach you how to size a fuse, you can click here for the specific blog post on that topic: https://www.explorist.life/what-size-fuses-to-use-for-a-diy-camper-electrical-setup/
Best Fuses & Fuse Holders for a DIY Camper Electrical Install
This list will show you the various types of fuses you will encounter during your DIY camper electrical install and teach you which ones are right for what purposes.
ANL fuses come in various sizes from 40A to 750A and have a max voltage of 32V (DC voltage only). These are good for any bigger loads such as Inverters, charge controllers, power distribution panels, or even as the main battery fuse. These fuses mount inside of an ANL Fuse Holder.
Use these fuses:
- ANL Fuses are recommended by the Manufacturer.
- Between the Battery Bank & main DC Distribution (Lynx Distributor or Busbars)
- To protect the DC wire going to an inverter
- To protect the DC wire going to a solar charge controller from the battery bank/busbars/distribution.
- To protect the DC wire going to your fuse block for branch circuits.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
MEGA fuses come in various sizes from 60A to 500A and have a max voltage of 32V - 70V (DC voltage only) depending on the model. These are good for any bigger loads such as Inverters, charge controllers or power distribution panels. These fuses mount inside of an MEGA fuse holder.
Use these fuses:
- When MEGA Fuses are recommended by the Manufacturer.
- Inside of a Victron Lynx Distributor
- To protect the DC wire going to an inverter
- To protect the DC wire going to a solar charge controller from the battery bank/busbars/distribution.
- To protect the DC wire going to your fuse block for branch circuits.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
The Victron Lynx Distributor is 4x MEGA fuse holder in one. This is a PERFECT solution for dividing up and protecting your circuits for your high amperage drawing devices such as an Inverter/Charger, Charge Controller, DC power distribution panel for branch circuits, alternator charging, etc.
This device is essentially a positive and negative busbar with 4 fuse holders all contained in one nice and neat package.
Class T fuses are recommended by certain Inverter manufacturers. If the Inverter you have chosen to use requires this type of fuse, this is the fuse you are looking for. These fuses are rated up to 125V DC.
Use these fuses:
- If the manufacturer of a specific component suggests it.
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
If you have a device that requires use of a Class T Fuse, this holder is where you will mount the Class T Fuse.
These fuses mount into a fuse holder that is designed to mount directly to a positive battery terminal. Unlike many of the other fuses which require a wire to go between the battery terminal and the fuse holder, this is a nice space saving option if it will fit in your particular battery space. These have a max voltage of 58V and come in various sizes from 40A to 300A.
Use these fuses:
- When you need to connect a fuse directly to a positive battery terminal.
- To protect the wire going from the starting battery to a DC DC charger or Isolator
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
- Circuits requiring a fuse larger or smaller than the max parameters of the fuse.
Blade fuses are common for protecting the wires going to the low-amperage branch circuits in your camper like lights, fans, usb outlets, refrigerators, etc; and are contained in a fuse block or DC distribution panel.
Use these fuses:
- When Blade Fuses are recommended by the Manufacturer.
- In 12V distribution panels or fuse blocks
Do NOT use these fuses:
- Circuits with AC voltage
- Circuits with DC voltage exceeding the max voltage of the fuse.
- Circuits where the fuse size required exceeds the max ampacity of the fuse.
This Power Distribution Panel houses both AC breakers for 120V circuits as well as Blade Fuses as shown above for all of the 12V DC devices in your camper (lights, fans, usb outlets, etc).
Charlie D
Friday 15th of April 2022
Running a 48V system. Assuming a standard ANL fuse won't do for the battery fusing on the bus bar. Do I need a 58v megafuse? Same for inverter and CC? Thanks!
Joy Dorant
Thursday 14th of April 2022
Hi Nate! I've added two additional solar panels to my system on their own 75 15 MPPT from Victron. I want to place a 20A fuse in between my MPPT and battery busbar. I can't find a 20A midi or mega fuse that can fit my midi/mega distributor. I was wondering if it is oké to get myself a 20A mini ANL fuse and put it in midi distributor. They seem to be the same size but since there are so my different ANL fuse holders on the market, I'm wondering if this would be a wise thing to do.
Cheers, Joy
Kevin Christofora
Wednesday 9th of March 2022
what is your feeling thoughts about an anl fuse versus a breaker? Do they function the same, would something like the blue sea fuse logically eliminate trying to replace a fuse when you are remote/offroad? Just thinking how to build the smartest and easiset set up for my new power inverter. And just curious.... are there any fuses or circuit breakers made in the USA?
Brian
Monday 28th of February 2022
Hello Nate: I don't want to be a pain, but I purchased a diagram and I can't access to it, I really want it, I think that your website, your videos and your blog are awesome, I can purchased again, I just want to know if maybe is a glitch in the system or it was a one time issue. I email you last week and forward the purchased invoice for you to check on it, please let me know what to do.
Alex Shneider
Wednesday 1st of December 2021
Hi
If I would like to use 2 batteries 75Amp each, what is the recommended fuse AMP? how to calculate the correct FUSE for such application?
Nate Yarbrough
Wednesday 1st of December 2021
The battery bank capacity doesn't have much bearing on fuse size. Here is a tutorial for determining fuse size: https://www.youtube.com/watch?v=5y-yDMEgV70&t=1s