Dual Battery system

[Greedy]

The fuses should be as close to the batteries as possible and are purely there to protect the cable. They say 100 amp but that is only if you're going to use the jumpstart override. 50 amp will be fine if only charging the batteries. The redarc is 400 amp rush if I remember rightly which is what is available when using jumpstart.

[Naff]

If everything on the load side is fuse protected, is there any purpose in fusing the line side? I suppose this is cascading, but I'm still struggling to see why there would be a situation where the cable would need protection.

[bortha]

Naffx214,
If your 2 battery's are side by side under the bonnet, there is no need to fuse them. The problem arises if you have one in the factory location and one in the tub or somewhere similar with a length of cable linking them. What can posibly happen is even when the refarc is isolated(assuming you have it under the bonnet), you still have 5 meters of unfused cable powered by the second battery. If this short out, and there's no fuse you will get smoke. Hope this helps
Bortha

[Naff]

Yeah that makes sense, cheers Bortha.

Despite the fact that I will run the positive cable to the rear tray in flex or anaconda (mechanical protection) there is a chance that over time it could cop a beating out 4wding and the sheath could get nicked etc.. short to chassis and cause problems. I'll fuse the auxillary battery and won't worry about the primary.

[Naff]

Next question - what the hell has everyone done in connecting an additional cable to the existing battery? This 35mm2 cable is pretty chunky, I can't see how to easily connect it to the positive terminal with all the gear already connected to it.

Any ideas?

[Greedy]

You cab buy terminals that will fit that size cable at most auto shops like supercheap etc. They are non insulated and can be found with different size bolt holes if the range is good enough. Crimping them is hard work though. Narva part numbers 57132, 57133 and 57134. These part numbers vary according to the stud sixe they suit (6,8 &10mm). I used the stud under the red cover in between the 2 fused links. I did have to cut the cover to allow the wire out. see below although the pic ain't the clearest

[Naff]

Thanks Greedy - that's where I was looking, but I can't remove that nut with anything! Might get the sparkies at work to do it for me - I can't undo anything they do up either They are going to do the crimping for me anyway.