Victron Smart Shunt Readings

[Ingwe]

Went to check on van today to clear out oven and grill etc (which we use for storage rather than cooking) in anticipation of habitation check.

Apart from the van being collected for its MOT and annual service last week it's been stood indoors with no hookup. I attach screen shots below from the app.

I decided to put it on hook up to ensure that the starter battery is topped up as although there is a battery master fitted (before having lithium batteries fitted) I sometimes find that the starter battery reads 12.5 volts rather than 12.7 12.9 which I understand to be the reading when fully charged. What I found a little confusing when I went to 'Trends' all it showed was activity on the starter battery which I don't understand. Should there not have been info on the leisure battery?

 

[Ditcha]

Have you got your starter battery connected to the shunt? If not it's a easy thing to do 1 wire job, on the trends screen you decide what you want to see by selecting the pull down menu were you have noneand starter battery

 

[Ingwe]

Have you got your starter battery connected to the shunt? If not it's a easy thing to do 1 wire job, on the trends screen you decide what you want to see by selecting the pull down menu were you have noneand starter battery

No, when they fitted the lithiums and the associated gear (shunt, mppt controller, ip22 charger and b2b) they said no need to connect starter battery to shunt. Said that the van’s control panel would suffice for starter battery reading.
I was thinking that a wire could go from the b2b to the shunt but not sure and unclear of the wire needed. Looking at Victron’s home page the shunt should have come with a lead for the starter battery.
How do these leads attach? Is it fairly straight forward for s DIY er?

 

[monzer]

Yes easy enough to connect to as long as the wires are long enough to reach from battery to shunt. You'll have to do this if you want to see the state of your starter battery via your Victron app.

 

[Lenny HB]

I see you are up north I know someone in Scotland that had trouble keeping the starter battery topped up with a Batterymaster from a lithium hab battery, I recommend he changed to an Ablemail battery maintainer, it solved the problem.

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[Ingwe]

Yes easy enough to connect to as long as the wires are long enough to reach from battery to shunt. You'll have to do this if you want to see the state of your starter battery via your Victron app.

Can i not go from the b2b to shunt? They’re right next to each other.

 

[Ditcha]

No, when they fitted the lithiums and the associated gear (shunt, mppt controller, ip22 charger and b2b) they said no need to connect starter battery to shunt. Said that the van’s control panel would suffice for starter battery reading.
I was thinking that a wire could go from the b2b to the shunt but not sure and unclear of the wire needed. Looking at Victron’s home page the shunt should have come with a lead for the starter battery.
How do these leads attach? Is it fairly straight forward for s DIY er?

Yeah you could take the feed from the b2b starter battery feed then to the shunt you are supplied with the fused wires from victron to do this it connects the Aux input on the side of the shunt to your starter battery.

See here.

https://www.victronenergy.com/upload/documents/SmartShunt/Manual_BMV_and_SmartShunt-en.pdf

 

[Ditcha]

Don't forget to set the Aux input in victron connect app to starter battery which I think you have as it's showing but just check

 

[autorouter]

No, when they fitted the lithiums and the associated gear (shunt, mppt controller, ip22 charger and b2b) they said no need to connect starter battery to shunt. Said that the van’s control panel would suffice for starter battery reading.
I was thinking that a wire could go from the b2b to the shunt but not sure and unclear of the wire needed. Looking at Victron’s home page the shunt should have come with a lead for the starter battery.

The shunt only measures the voltage of the starter battery, it doesn't measure any amps like it does for the leisure battery. It was originally designed to keep an eye on the 'midpoint ' voltage of a 24V leisure battery bank - two 12V in series - but if the leisure battery is 12V it can be repurposed to keep an eye on the starter battery voltage. So in that sense it doesn't give you any more information than the van's control panel. But I suppose it might be more accurate and reliable.

For perfect accuracy you should run a single continuous wire all the way from the shunt to the starter battery (with a fuse, maybe 2A or 5A). If you run the wire to the starter battery input of the B2B, then there will be a small error due to voltage drop while the B2B is operating (while the engine is running). I think when the engine is stopped there will be no error.

 

[Ingwe]

The shunt only measures the voltage of the starter battery, it doesn't measure any amps like it does for the leisure battery. It was originally designed to keep an eye on the 'midpoint ' voltage of a 24V leisure battery bank - two 12V in series - but if the leisure battery is 12V it can be repurposed to keep an eye on the starter battery voltage. So in that sense it doesn't give you any more information than the van's control panel. But I suppose it might be more accurate and reliable.

For perfect accuracy you should run a single continuous wire all the way from the shunt to the starter battery (with a fuse, maybe 2A or 5A). If you run the wire to the starter battery input of the B2B, then there will be a small error due to voltage drop while the B2B is operating (while the engine is running). I think when the engine is stopped there will be no error.

So, in reality, I can keep my eye on the starter battery’s voltage adequately with the van’s control panel allowing for voltage drop? If so it hardly seems worth the effort to run a wire from the shunt to the starter battery.

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[Hoovie]

The shunt only measures the voltage of the starter battery, it doesn't measure any amps like it does for the leisure battery. It was originally designed to keep an eye on the 'midpoint ' voltage of a 24V leisure battery bank - two 12V in series - but if the leisure battery is 12V it can be repurposed to keep an eye on the starter battery voltage. So in that sense it doesn't give you any more information than the van's control panel. But I suppose it might be more accurate and reliable.

For perfect accuracy you should run a single continuous wire all the way from the shunt to the starter battery (with a fuse, maybe 2A or 5A). If you run the wire to the starter battery input of the B2B, then there will be a small error due to voltage drop while the B2B is operating (while the engine is running). I think when the engine is stopped there will be no error.

What he said I was going to make the same point as Autorouter. On a SmartShunt there is little to be gained in terms of monitoring the starter battery voltage for the typical user.
It does sound like the installer couldn't be bothered to run a wire so used an excuse instead though.

There are however 3 possible advantages to connect ....
1) You can check the SB Voltage on the phone if you are too lazy to stand up and use the existing control panel
2) You can set an alarm on the Smartshunt on the SB voltage, so get warned if it is too low - OR too high. Have to say I have never used this option but it is there notheless.

3) This applies to the BMV-702/BMV-712 rather than the Smartshunt, but other readers might be interested .... You can control the BMV Relay based on SB Voltage. I have actually used this to monitor the voltage of a battery connected to the Aux and when it got low, turn on a battery charger.

 

[BILL 875]

I plan to install a lithium battery and B2B so heres a question do you need a smart shunt or do you get the same info from the BMS app or is not that simple. Regards Bill.