Victron Smart Shunt

[Samebutdifferent]

I'm going to fit a shunt and was wondering if anyone knows if it would be ok to simply replace this with the shunt? I've not seen a connector block like this before.





I'm not sure what the small white & black wires are or why they're connected like that, but they need to be connected together with the other cables on the load/system side of the shunt.

This is the Shunt:

 

[Grand Tourismo]

I have simply no idea SBD, I'm not even sure what a shunt is!!...but that little green block looks a tempting home for those black and white wires!!
(which is me reaching the extent of my electrickery knowledge)

A wiring diagram would be handy...can the chap at solar solutions assist or at Victron?

 

[Samebutdifferent]

A wiring diagram would be handy...can the chap at solar solutions assist or at Victron?

Wiring diagram!!! Tell me about it!
I might have to contact Roger Donoghue but it seems from another post on here he is quite elusive.

I have simply no idea SBD, I'm not even sure what a shunt is!!...

SHUNT:
A battery monitor is a device which is able to tell you detailed information on load and charge of a battery. It also monitors battery history and the number of cycles a battery goes through. Battery monitoring in a van conversion is really important as discharging your batteries too much can lead to damage.

This applies to both AGM & Lithium ion batteries the core difference being the maximum level of discharge you can go to, 50% for AGM and 80% for lithium ion.

A battery monitor with ammeter functionality measures the input and output of a battery by analysing the current flowing in/out of the positive and negative terminals. It requires all grounded wires to ground on a shunt which is then connected to the negative terminal, while no positive interception is needed and a connection is made directly to the battery.

This shunt is the core brains of the battery monitor and is what the user interface panel is plugged into.

The smart shunt doesn't require a monitor but still has a interface connection (RJ12) for that function, see VE direct in pic above.
It doesn't require the monitor as it connects to and app, so all info if available on your phone/ipad, therefore great where space is at a premium like the MP

.but that little green block looks a tempting home for those black and white wires!!
(which is me reaching the extent of my electrickery knowledge)

The connection to the VBatt+ is required to monitor the leisure battery. If you want to monitor the starter battery the Aux needs to be connected to the starter battery +pos terminal.

I just don't know why the original pic looks like a fuse on a -neg earth lead?

I fitted a BMV-712 that required a monitor (the smart shunt just requires an app) along with a Votronic solar regulator to my previous Ducato, the shunt is seen here to the left of the pic:





A simple volt meter is ok but doesn't really tell you much. I think battery management is very important, especially if you spend time off grid. A monitor gives you so much info because it can tell you exactly whats going/gone into the battery as wells what going/gone out.

 

[Samebutdifferent]

Ok, I asked this question elsewhere and what we are looking at is in fact a shunt, obvious when you think about it.

It is this shunt that provides the voltage reading and the crude %age SOC bar graph in the control panel screen.

The Victron shunt has a ammeter function and so is far more informative than the original fitment. I have the choice of simply replacing the original fitment but I'm not sure if the control panel will still work. It can be wired in series and both will work, probably what I will do.

 

[Grand Tourismo]

Thanks for the description, much clearer to me now anyway!

Therefore the black and white/black wires have to be sender wires to the control panel screen (as far as I can see there is no other way the readings can be sent on the original shunt set-up)

I think on balance I would attempt to replace the original shunt with the new Victron rather than wire in series. Is there a chance that the bolt centre measurement on the MB shunt matches that of the Victron? Can you just swap the brass "jump" plate over by any chance?

 

[Grand Tourismo]

The connection to the VBatt+ is required to monitor the leisure battery. If you want to monitor the starter battery the Aux needs to be connected to the starter battery +pos terminal.

So the green block is the home for the black & black/white wires after all?

I just don't know why the original pic looks like a fuse on a -neg earth lead?

I can't see the fuse on the neg side?

 

[Samebutdifferent]

So the green block is the home for the black & black/white wires after all?

No, see this diagram. The shunt is supplied with two red fused wires, one is connected to the +pos of the leisure battery and has to be connected for the shunt to work.

The shunt can also monitor the voltage of the starter battery if required, the AUX then needs to be connected to the +pos of the starter battery.

As you said previously the black and white wires are the connection to the control panel display. If a device is required to show info from the smart shunt, rather than connecting by bluetooth, that is connected to the VE Direct terminal with a RJ12 cable. That's what I show above, you can see the two red wires for batteries into the green terminal and a grey/white RJ12 cable connecting the shunt to the round monitor.

I can't see the fuse on the neg side?

I just thought the unit resembled a mega fuse when in fact the most obvious thing it resembles is a shunt DOH!!!

 

[Samebutdifferent]

I would say @Grand Tourismo that I'm paranoid about battery usage/SOC

Many years ago when contemplating camper-vaning I hired one for the w/e. Everything went fine, we were on hookup and the gauges all seemed ok, until I tried to start the engine..... nothing. Had to get a tow start by a tractor. That was when my obsession with battery monitoring was born.

I've not solved the problem of hair loss yet

 

[Grand Tourismo]

I would say @Grand Tourismo that I'm paranoid about battery usage/SOC

Many years ago when contemplating camper-vaning I hired one for the w/e. Everything went fine, we were on hookup and the gauges all seemed ok, until I tried to start the engine..... nothing. Had to get a tow start by a tractor. That was when my obsession with battery monitoring was born.

I thought that the starter battery on the MP is "isolated" from being drained by the MB control system. Still not a good result but I thought the fridge, heater, roof, et al, all shut down before any drain can occur to the starter battery?
In my old road car you couldn't even get the radio to play if the starter battery got to a certain level, ensuring the car always started.

I've not solved the problem of hair loss yet

Easy, peaked cap or a hair prosthesis...or enough Brewdog that you don't care anymore!

 

[Grand Tourismo]

No, see this diagram. The shunt is supplied with two red fused wires, one is connected to the +pos of the leisure battery and has to be connected for the shunt to work.

The shunt can also monitor the voltage of the starter battery if required, the AUX then needs to be connected to the +pos of the starter battery.

As you said previously the black and white wires are the connection to the control panel display. If a device is required to show info from the smart shunt, rather than connecting by bluetooth, that is connected to the VE Direct terminal with a RJ12 cable. That's what I show above, you can see the two red wires for batteries into the green terminal and a grey/white RJ12 cable connecting the shunt to the round monitor.



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I just thought the unit resembled a mega fuse when in fact the most obvious thing it resembles is a shunt DOH!!!

View attachment 1601

All clear...what I don't understand is why the MB bk & bk/wh spade connectors are mounted on the same brass link? surely this causes the MB shunt to be bypassed? or at least a leak past?
Do you think you could use the MB link plate on top of the Victron shunt?

 

[Samebutdifferent]

All clear...what I don't understand is why the MB bk & bk/wh spade connectors are mounted on the same brass link? surely this causes the MB shunt to be bypassed? or at least a leak past?
Do you think you could use the MB link plate on top of the Victron shunt?

This is the reason:

The entire current flows through the shunt and generates a voltage drop, which is then is measured. Using Ohm's law and the known resistance, this measurement can then be used to calculate the current (I = V/R). To keep power loss - and thus heat generation - to a minimum, shunts must have a very low resistance value measurable in milliohms.

So it has to be either side of the to measure the voltage drop. The VE Direct terminal probably does the same thing but we can't see it.

I think it's either wired in series and retain the panel readings or replace the original and have all the info on phone/ipad.

Regarding the flat starter battery, the rental van batteries were also supposed to be isolated, even more reason to be paranoid