Fitting a 12V Fuse Box

DISCLAIMER: Working with electricity can be dangerous. I am not a professional electrician, nor do I have an extensive history with electrics. All the information provided has been gathered through advice and my own research and is specific to my electrical system.

A series of electrical items for wiring my 12v fuse box


TOTAL: £134.41

Before I can wire up my 12V appliances like my lights, fridge, roof vents and heater, I need to install a 12V fuse box as part of my electrical system. This fuse box takes the positive and negative of each appliance and then you can individually fuse each appliance. 

As well as a fuse box, I’m also going to install a Battery Protect from Victron. As it can damage your leisure batteries if you discharge them too low, the Battery Protect will monitor your battery bank and then automatically disconnect your 12V appliances if it discharges too low. Very handy. 

Click here to see my full wiring diagram and section being described in this post.

Wiring 12V Fuse Box and Battery Protect

A close up of my installed fuse box and battery protect

After mounting all my units in place, the first thing I did was measure out all the cables I’d need, cut the cables, then stripped, crimped and heat shrunk each end. 

I then connected the negative end of the fuse box directly to the negative busbar. 

I connected the positive end of my fuse box to the kill switch, the kill switch to a 100A fuse, then the fuse to the OUT terminal of the Battery Protect. 

I chose a 100A fuse because the 16mm cable I was using has an amp rating of 110A, so the fuse would blow before the 110A limit is hit. 

Before connecting the IN terminal of the Battery Protect to the positive busbar, it has a negative wire that can be wired straight to the negative busbar. After that, I connected the Battery Protect to the positive busbar. 

As soon as I did, I saw the Battery Protect light up and I was able to connect to it via the Victron app. 

If you have any questions at all, feel free to ping me an email or drop me a message on Instagram!