Placement of battery monitor shunt

[Oscarpop]

We are going to install the Victron BMV 600 which requires the placement of a shunt.

As you can see from the picture we have 300ah of house batteries.

The shunt has to be connected to the -ve, so my question is, does the shunt connect between the -ve post of the 3rd battery from the top of the screen, or the -ve post at the top of the screen?


Also, the cable present is 24mm ( which is about the thickness of my thumb).

The battery connectors Halfords sell are 16mm.

Should I get a connecting cable the same size (24mm) or will 16mm suffice?

Many thanks.

 

[Playtime]

I would suggest connecting directly to the battery negative of the top battery (i.e. the 3 in parallel) and connect the existing cable to the other side of the shunt.

The single battery at the bottom of the picture is either the engine start battery or a stand alone battery for windlass, bow thruster or maybe even the VHF.

If you can arrange suitable strain relief for the existing cable and some anti vibration arrangement for the shunt you could screw the shunt directly to the battery terminal (in place of the original cable). You then wouldn't need a new cable - just attach the existing cable to the other side of the shunt.

If you decide to screw the shunt to the woodwork, keep the new cable as short as possible. Assuming you are never going to draw more than 100A through the new cable I would suggest 16mm would be OK. However, Halfords cables are not the best. It would be better to get a short cable custom made using marine grade wire and crimps.

 

[VicS]

As Playtime says . between the heavy black cable and the negative terminal of the battery at the top of the picture.

Regard the shunt as doorway with a sensor ( the battery monitor) attached.

All the current going to or from the battery must pass through the doorway for it to be recorded by the sensor