Shunt wiring question

[Outnabout]

Victron's programming is more sophisticated, and it has that bluetooth which I use A LOT. The price diff is huge. That said, if I was wanting to save money I would go Victron, with the smart shunt.

How To Fit, Install And SetUp A Victron BMV-712 Bluetooth Battery Monitor For Motorhome Solar. - YouTube

Thanks for all the help.
Another question I have: If I ran the second positive wire to the Blue Sea isolator and connected it to the positive wire coming in from the truck, would that give me a way to track the voltage or SOC of the truck starting battery?

 

[Vic Harder]

No. To track the SOC of the truck battery you would need another BMV/shunt that utilizes the -ve (ground) wire between the truck battery's -ve post and ground.

 

[Outnabout]

No. To track the SOC of the truck battery you would need another BMV/shunt that utilizes the -ve (ground) wire between the truck battery's -ve post and ground.

Would I be able to just measure voltage?

 

[Vic Harder]

Um, no... especially not since you are talking about the "positive" wire on the truck battery. The positive wires of the batteries are NOT connected to the shunt... (well, not true... a tiny wire is used to power the shunt). The shunt is the path of the ground wire only.

In my HAWK build with my previous truck I had a volt meter in the cab with a switch so I could toggle between battery banks and get a reading from either.

 

[rando]

With the BMV-712 you actually can measure the voltage of a second battery. Just the voltage and not the SOC, but it still can be useful. Your idea to run the 2nd battery wire to the truck/alternator terminal on the ACR should work well.

 

[Outnabout]

With the BMV-712 you actually can measure the voltage of a second battery. Just the voltage and not the SOC, but it still can be useful. Your idea to run the 2nd battery wire to the truck/alternator terminal on the ACR should work well.

Thanks. I am considering a portable AC/DC fridge, behind the truck seat and powering from the existing 12v outlet. I figure if I install the BMV-712 I could also keep an eye on the starter battery voltage. The solar on the camper also charges my truck battery so I am fairly confident that I wouldn’t run the truck battery too low but want to be cautious and information is never harmful.

 

[Vic Harder]

With the BMV-712 you actually can measure the voltage of a second battery. Just the voltage and not the SOC, but it still can be useful. Your idea to run the 2nd battery wire to the truck/alternator terminal on the ACR should work well.

How? Did I miss a page in the manual?

 

[ntsqd]

The TriMetric models can also monitor the voltage only of a second battery bank by scrolling thru the display options (& assuming that ti was wired to do so).

 

[dscobell]

With the BMV-712 you actually can measure the voltage of a second battery. Just the voltage and not the SOC, but it still can be useful. Your idea to run the 2nd battery wire to the truck/alternator terminal on the ACR should work well.

I did this when I installed the Victron 712 unit in my truck. With the truck not running ,the voltage difference between the 712 display of the truck battery and the actual voltage measured at the truck battery was interesting. I assume this is explained at least in part by the voltage lost over the run of 10 gauge wire from truck to ACR.

 

[rando]

How? Did I miss a page in the manual?

Section 1.2 (page 5 in English, or page 6 in Dutch ).

 

[Outnabout]

With my Blue Sea 7611 I can charge my truck through solar, so until voltages drop below the connection threshold I imagine I will see the same voltage for both sets of batteries.

 

[Vic Harder]

Section 1.2 (page 5 in English, or page 6 in Dutch ).

Huh, I suppose I put that completely out of mind because I am actually USING that functionality, but for the temperature sender. Selective memory at its best!

 

[ntsqd]

With my Blue Sea 7611 I can charge my truck through solar, so until voltages drop below the connection threshold I imagine I will see the same voltage for both sets of batteries.

That is what I would expect to happen.