Cable Size for Hab Batts ?

[Marauder]

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So now that I started mucking about with connections and wiring, I guess I should upgrade the scabby old wiring between my 2 Hab Batts.

The cabling from body to first batt looks pukka, and is protected by 50a fuse (photo)

there is also a 2a fuse but I dont know what that's for.

The second batt is connected parallel to original Batt by wiring which has a 20a inline fuse. The way this is set up leads me to believe Batt2 and it's wiring are not original.

I intend to replace this cable with new, and introduce QR post clamps along with the BM graciously provided by EddieVanBitz.

So what spec cable should I now use to connect the 2 leisure Batts to each other ? Victron urge Tri-Rated, warning of fire risk: (photo)

( I don't want a fire risk thanks )

do I really need a fuse between the 2 Hab Batts ?
If so, is a 20a fuse adequate, ( and, why is fuse in photo a 50a version ?)

all comments and advice warmly accepted, as always.


AND A BIG THANKS TO THOSE WHO OBVIOUSLY DO THIS STUFF FOR A LIVING, BUT STILL GENEROUSLY TAKE TIME OUT TO HELP NUMBNUTS LIKE ME FOR FREE AND GRATIS.

MERRY CHRISTMAS TO YOU ALL
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[pappajohn]

Ideally the link wires should be the same size as the output to hab area.....the 50a fuse is to protect the hab wiring as a whole.
If the batteries are side by side and no possibility of shorting then no fuse needed.
If they are separate the a fuse at each end of the link is advisable.
The reason for each end ....if the link shorts to earth one fuse will blow but the other battery is still feeding the shorted wire.
Fuse at each end and both blow isolating both batteries .

 

[Lenny HB]

The 2 amp fuse powers the standby circuit of the Elektroblock.
If the batteries are next to each other you don't need a separate fuse. Use 16mm sq cable to connect the batteries.

 

[Marauder]

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Many thanks guys, the double fusing precaution is a neat idea.

But what is the standby circuit of the Elektroblock ? Do I need to know more about it ?

I also need to replace the temporary cable I used to test Victron MPPT100/20
what cable would Lenny suggest to suit the specs Victron stipulate in screenshot from my post above ?
( cable to go from PV supply bus into the MPPT screw terminals )
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