Victron Battery Monitor Install Question

[dlochner]

A question about the shunt. As it comes from the factory, the circuit board is on the left side as the current flows. That is problematic for my install. Can I remove the circuit board and turn it upside down, that would put the board on the right side as the current flows?

The positive terminal on the batteries is getting a little crowded. The main feed goes to a bus bar, can I attach the positive wire to the bus bar without sacrificing the function of the battery monitor? The monitor will be primarily used to show current flow, a Balmar Smart gauge is also installed to monitor SOC.

 

[Bill Roosa]

a picture or product name would be helpfull so we can have some idea what you are talking about.
Shunts can have current flowing in either direction, think charge and discharge. The only thing that should be connected to the battery + terminal is the shunt. The rest of the loads and DC sources should be connected to the other side of the shunt. Most of us use the ground side of the circuit becasue it has fewer cables to deal with.
With out knowing the model I'd venture the following: if you hook it up "backward" it will just read backward. ie charge when the batterys are actually discharging and discharge when they are actuall charging. that may or may not be a problem with the monitoring circuit board.

 

[Bill Roosa]

Sorry, I see that you put the product in the title, need more coffee

 

[Bill Roosa]

Assuming BMV-700 the circuit board appears to be connecte to the center of the shunt so going to need some help understanding what you mean by "on the left" and "as the current flows"

 

[dlochner]

Assuming BMV-700 the circuit board appears to be connecte to the center of the shunt so going to need some help understanding what you mean by "on the left" and "as the current flows"

Bill,

Thanks for your efforts. Let me try to clarify.

The battery side and the load side of the shunt are determined by a little circuit board attached to the shunt. On the circuit board are connections to the gauge.

Perhaps the simple question is can I remove the circuit board and reinstall it "upside down?" That way the connections would be on the right side of the shunt as the current flows back to the battery. (really thinking about the discharge cycle here, not so much the charge cycle)

Another way of asking the same question is, "Is there anything in the shunt that determines battery side vs load side other than the circuit board?"

 

[Maine Sail]

Dave,

You can flip the shunt PCB if you need to..

 

[dlochner]

Dave,

You can flip the shunt PCB if you need to..

Thought that was the case, but wanted to make sure.

Thanks.

 

[Bill Roosa]

Shunt 101.
A shunt is just a really well defined part of the circuit. You absolutly know the resistance between the two shunt sense terminals (not the current terminals). In your case the circuit board has those connections where it screws to the shunt so the screws are the sense terminals. In more normal shunts the sense terminals have wire coming off each one and they go to a remote circuit board/guage.
Since you know the resistance between the sense terminals you can do the following math:
V=I*R where R is resistance, I is current and V is voltage
R is known and if you measure the voltage drop across it you can get to I=V/R.
So an ammeter is just a voltage (drop) meter using a known resistance.
Hooking it up backward will just make the guage read backward also.
The catch comes when the guage is a monitor. It is probably expecting the current to be flowing in a specific direction during battery charge so connecting it backward will not harm the unit but it may not be able to tell you stuff without some mental effort. negative SOC, negative time till discharged, etc.
A close examination of the shunt or curcit board should reveal a + or - sign stamped or printed on the unit. If the unit reads backward after hooking it up either flip the current carrying cables or flip the circuit board.
If you tell me the model # I'll try and sort it out for you.