Fusebox vs Bus Bar Question

[ben5560]

Just at the stage where i am designed my 12V system, and looking at Bus Bars and MIDI fuse holders. I came across a 4 way MIDI fuse box, made by HELLA:



My question is, why do i need a positive bus bar and separate individual MIDI fuse holders, when i can run everything from here?

My lithium battery has an MRBF fuse on it, and will run into this, to power/connect to:

• Victron XS50 DCDC Charger
• Victron IP22 Charger
• Autoterm Heater
• Output to 12V Distribution Fuse Box

So can i not run a cable from the lithium battery, straight into one of these and just have a negative bus bar?

 

[Salty Spuds]

Without seeing the wiring diagram it's difficult to give an answer, where the fuses are in the system is just as important as the fuse & cable sizing. What you're trying to avoid is unprotected runs of cable, so positioning is crucial.

 

[ben5560]

Effectively going to have this midi fuse box right next to the leisure battery, under the driver seat. The cable that goes from this MIDI fuse box to the 12V distribution fuse box will be 16mm2, and will run to the back of the kitchen on the C Pillar area for the fusebox.

The 12v loads in the back are maximum 18 amps, accounting for fridge start up surges.

 

[Dellmassive]

Just at the stage where i am designed my 12V system, and looking at Bus Bars and MIDI fuse holders. I came across a 4 way MIDI fuse box, made by HELLA:

View attachment 320498

My question is, why do i need a positive bus bar and separate individual MIDI fuse holders, when i can run everything from here?

My lithium battery has an MRBF fuse on it, and will run into this, to power/connect to:

• Victron XS50 DCDC Charger
• Victron IP22 Charger
• Autoterm Heater
• Output to 12V Distribution Fuse Box

So can i not run a cable from the lithium battery, straight into one of these and just have a negative bus bar?

Those are what I used off both my battery's..

Remember the fuse is to protect the cable.

...





See here...

Post in thread 'Dellmassive`s Camper Van Adventure'

17 Aug 2025

Adding a second 230ah ROAMER 230SBG4

@RoamerBatteries

.

it finally arrived. - this one is going under the passenger seat. . .



a quick charge up with the 100A charger. . . . so the two batterys can be joined.

always make sure BOTH batterys are 100% full before joining together.




a quick 77A charge lol.



this is the original one,



and this is the second one,




combined we get 460ah of battery bank.


.


the twin battery bank worked a treat...

• Dellmassive

• 

 

[ben5560]

Perfect, that's exactly what I'm looking at - so I'm right, I don't need a positive bus bar and can just have all my midi fuses in that box, to protect all of the wires

 

[ben5560]

Excuse the mad drawing, first attempt!