This DIY Busbar system is a great way to keep the main fuses nice and organized in a small space giving your camper van solar install a professional look.
IMPORTANT UPDATE: The fuses & fuse holders shown in the pictures and the video are NO LONGER RECOMMENDED. Quality control on these have gone DRASTICALLY downhill over the last few months and many have had issues with these not being able to flow their rated current, heating up, and melting the fuse holders.
So… Moving forward… I HIGHLY recommend using the Busbar and fuse holder solution that is the Lynx Distributor. I have already place the Lynx Distributor in my most recent diagrams at https://www.explorist.life/solarwiringdiagrams and will be phasing out the diagrams that do not use the Victron Lynx Distributor.
If you REALLY want to use the DIY solution on this page, that’s still fine; but I MUST recommend using Blue Sea Fuse Holders & Blue Sea ANL Fuses as they are tested and certified pieces of equipment.
The links throughout the rest of this blog post SHOULD be updated with blue sea fuses and fuse holders; but if you stumble across non-name-brand fuses or holders, please do not use them and let me know where you see them.
Using 4/0 wire between your batteries and Inverter? Upgrade your copper bar to 1/4″ x 1 1/2″ rather than the 1/4″ x 3/4″ we use for a 2/0 wire equivalent.
Buy your copper bar here: https://www.onlinemetals.com/en/buy/copper/0-25-x-0-75-copper-rectangle-bar-110-h02/pid/4283
ANL Fuse Holders: https://amzn.to/37b6pCD
Disconnect switch for 2/0: https://amzn.to/2ZdejIk
Disconnect switch for 4/0: https://amzn.to/33vNOfL
Victron BMV-712 Battery Monitor (Shunt): https://amzn.to/3156Jw8
For ANL Fuse sizing please see: https://www.explorist.life/solarwiringdiagrams
The first thing I’m going to do is to cut and drill my copper bar. Here is a cut and drill list of the pieces I’ll be making. The below diagram has been tested for 2/0 wire equivalent copper bar and switch. If using 4/0 wire, please pre-measure to verify hole placement.
I’m using a Dewalt Portable Band Saw and SWAG Table, but since copper is a soft metal; this could also be cut with a hacksaw.
The next thing I am going to do is to clamp those pieces of copper into my bench vise and drill some holes in the copper.
For this I’ll be using a 7/16” Drill Bit, a ⅜” Drill Bit, and a 5/16” Drill Bit spun by a Dewalt Cordless Drill. If I had a drill press or even a high speed corded drill, that would be much preferred… but here we are. Anyway, copper is a soft enough metal so with a fresh, sharp drill bit; this process is fairly painless.
Now I’m going to connect my 2-hole and 4-hole bus bars to my master disconnect switch using a 9/16” Wrench.
I’m going to position these two busbars so that when I’m looking at the face of the switch; the 2-hole busbar is on the left and the 4-hole busbar is on the right.
Next, I’m going to install the ANL Fuse holders onto the 3 holes coming off the load side of the master disconnect switch
After that, I’m going to do the same thing on the 2-hole busbar side of the master disconnect switch but the one difference will be that I am not going to have the washer below the busbar nor the lock washer above the busbar as there will not be enough room once the wire lug and ANL Fuse is installed.
Now would be a good time to fasten my Positive Busbar and the shunt from my Victron BMV-712 Battery monitor in the location that it is going to live within the system. I would position the shunt and positive busbar like this with the “Battery” side of the shunt directly under the right-most ANL Fuse holder:
After those are secure; on the side of the ANL Fuse holders that are opposite the positive busbar I’m going to remove the top nut, lock washer, washers and loosen the bottom nut with a 9/16” wrench and spin it up off the base of the ANL fuse holders about a quarter inch.
Now It’s time to position all of the wires and attach them to the positive and negative busbars using a ⅜” rachet, 6” extension, 9/16” socket, and an 11/16” Socket. All of the positive wires will fit on the ANL Fuse holder studs with a 5/16” lug. Slide the wire lug over the ANL Fuse holder stud; replace the washer and lock washer.
Next I’m going to Install the ANL Fuses. The fuses simply slide in place between the washers like this:
Now I’m going to need the 3-hole busbar, two – 1” long – 5/16’ x 18 hex bolt, 4 washers, and 2 lock washers.
Using the wiring diagram from explorist.life/solarwiringdiagrams as a reference, I’m going to attach the wires with the 5/16” lugs to the 3-hole busbar using the hex bolt setup I just mentioned tightening it up with a 1/2” socket and wrench. I need to position the copper bar itself between the two lugs.
For the remaining two wires on the far left side; these two lugs need to be drilled out with a step bit to fit the bigger bolt of the shunt.
After those lug holes have been enlarged, I’m going to bolt those two lugs and the copper bar to the “Load and Charger” side of the shunt with a 11/16” socket. I don’t have enough room for the washer and lock washer for the shunt so I’m just going to leave them out. Flipping the bottom lug ‘upside down’ will make these two lugs fit together better.
Now, I’ve got a complete positive and negative busbar. The only other thing to do now will be to connect them both to battery power.
I’ll have to enlarge the negative lug with a step bit to properly fit just the same as earlier and attach this lug to this stud with an 11/16” socket.
For the positive wire; I need to make sure that the positive lug is directly contacting the copper bar with the fuse sitting on top of the lug rather than below it.
but before I bolt the positive battery cable down, I want to attach the power wire for the little circuit board for the Victron BMV-712.
The positive wire for the shunt is really long and I really only need it to be about 14”, so I’m going to cut it down to size and use a butt-splice connector to rid myself of the excess wire making sure to leave the inline fuse intact.
Connect the shunt positive to this stud:
…and connect the other end to the B1 side on the front of the shunt.
When I get ready to run the Victron BMV-712 Battery Monitor display panel, that data cable simply inserts right here:
And that’s all there is to it!
Sunday 10th of July 2022
Hi Nate, do you have any experience with the Littelfuse 880089? I'm working on a 24V system that won't have an inverter, so all my main major loads are in the 20-50A range. The Lynx Distributor bottoms out at ~40A as far as I can tell with the MEGA fuses, so it seems overpowered for what I need. The Littelfuse 880089 seems right on spec-wise for what I need, but I'm heeding your caution at the beginning of this post!
Thursday 10th of February 2022
Everything looks great except that small wire ring 5/16" lug terminal. Unfortunately, all small wire ring terminals have the smallest OD possible for 5/16" studs. Evidently they do this because the small wire is low current. But the stud is designed for high current connections The OD is too small for good clamping bearing area and the reduced conduction area may be problematic since the other lug ring will try to flow current through that narrow small wire ring terminal.
The ring OD should be the same (large as required by the stud) for all wire sizes - but again, no one makes them as such.
Wednesday 9th of February 2022
Hi Nate, Awesome stuff! I wish I had found your site a long time ago!!! My situation has a few differences. I have an 5th wheel, so my shore power is already connected to the Converter/Charger. I will upgrade to an Iota DLS 55 with the IQ & Turbo modules. I will up the ga on the wire. I had already gathered all the componets for the bus bar before I found your Upgrade to the Victron Lynx. My question is on the left side (1st connection) of the On/Off switch. At the bottom, is that coming from the battery bank and the top wire going to the ??? Converter? I will be using a small solar system and a generator. I do some winter RVing at high elevations and very cold temps.
Friday 16th of July 2021
Where do I go to purchase one that you would make for me? Thank you
Thursday 8th of July 2021
Hi Nate, I have installed a full Victron setup with drop in lithium batteries,when i install the battery isolator the 12v system goes hay wire with the voltage going to 1mp to 8amps on all cables and batteries, remove isolator everything works perfect, tried different isolator same problem,have setup busbar- as above and one purchased one for +.
Victon good stuff but not much support in Australia.
Best regards Bob