Charger and battery upgrade.

[Itsmcb]

About to upgrade my power reserve from a single 110 amp battery to 2 X 130 amp Hankook XL31 batteries and a Victron 30amp mains charger (instead of the current 10amp 13.8 onboard)
I've order some 10mm2 cable to connect everything up but want to check on the fuse(s) I should use.
Setup as the little sketch (hopefully correct). Should I have fuses at point A, B and C? If so what rating?
I was thinking of using the individual strip fuses in holders like picture 2.
All good? or any better suggestions?

 

[pappajohn]

35a fuse at EACH END of the Pos link wire.
35a fuse in the charger Pos wire.
Nothing in the Neg wires.
Don't understand the fuse box.... Pos to Neg will instantly blow all the fuses as a dead short.
If both batteries are next to each other and absolutely no possibility of the positive link wire shorting to earth then a fuse at each end is NOT required but a single 35a fuse at one end is.

 

[XxAnthxX]

Don't understand the fuse box....

My understanding is that it is the vans fuse/distribution board that will then supply all of the 12v requirements to the van, through individual fuses for those circuits.

 

[pappajohn]

My understanding is that it is the vans fuse/distribution board that will then supply all of the 12v requirements to the van, through individual fuses for those circuits.

Agreed, but the diagram shows a Pos AND Neg connection to the fuse block.....a dead short.
The fuse box should have a Pos connection only then individual circuits from the individual fuses.

 

[XxAnthxX]

Agreed, but the diagram shows a Pos AND Neg connection to the fuse block.....a dead short.
The fuse box should have a Pos connection only then individual circuits from the individual fuses.

My leisure batteries have a positive and negative feed directly into the fuse/control unit.....

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[Itsmcb]

Agreed, but the diagram shows a Pos AND Neg connection to the fuse block.....a dead short.
The fuse box should have a Pos connection only then individual circuits from the individual fuses.

The fuseboard is the existing one. There is a connection to the live side to feed the fuses. The negative connection goes to the negative busbar and all the negative returns come back to there. It was more the battery and charger links I was concerned about.

 

[Itsmcb]

35a fuse at EACH END of the Pos link wire.
35a fuse in the charger Pos wire.
Nothing in the Neg wires.
Don't understand the fuse box.... Pos to Neg will instantly blow all the fuses as a dead short.
If both batteries are next to each other and absolutely no possibility of the positive link wire shorting to earth then a fuse at each end is NOT required but a single 35a fuse at one end is.

The positive link wire will only be about 300mm long.

 

[XxAnthxX]

The fuseboard is the existing one. There is a connection to the live side to feed the fuses. The negative connection goes to the negative busbar and all the negative returns come back to there. It was more the battery and charger links I was concerned about.

Pretty much what pappajohn says then.

The thin walled 10mm2 cable will be good for about 70a which is what your protecting.

I‘d keep your + and - battery link cables the same length too.

 

[pappajohn]

The positive link wire will only be about 300mm long.

OK, if there's no possibility of the wire chaffing on sharp edges etc then just one fuse at one end will suffice.
It's only there incase a battery developers an internal short circuit and will blow and seperate the two batteries.

 

[pappajohn]

The fuseboard is the existing one. There is a connection to the live side to feed the fuses. The negative connection goes to the negative busbar and all the negative returns come back to there. It was more the battery and charger links I was concerned about.

OK, it's was a bit confusing on the sketch.

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[Itsmcb]

OK, it's was a bit confusing on the sketch.

Apologies, I only included it to show the cables leaving the battery.
Are there a better fuse holders I could use on the link between the batteries?

 

[pappajohn]

Are there a better fuse holders I could use on the link between the batteries?

Just a standard car type blade fuse will be fine.
Easy enough to source a fuse holder... Halfords etc... For a blade fuse.
The one in your photo is more appropriate for inverters etc where it could be passing 300amps or so.

 

[autorouter]

Are there a better fuse holders I could use on the link between the batteries?

Those fuse holders in the picture are Midi type, and are perfectly good for what you describe. I prefer them to blade fuses, especially the larger ones. Not to be confused with Mega fuses which look similar in shape but are bigger and carry heavier currents.

 

[Itsmcb]

Those fuse holders in the picture are Midi type, and are perfectly good for what you describe. I prefer them to blade fuses, especially the larger ones. Not to be confused with Mega fuses which look similar in shape but are bigger and carry heavier currents.

Thanks, I have ordered these now as I couldn't easily find a blade fuse holder that would accept the 10mm2 cable.