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fkfw avatar image
fkfw asked

BMV-712 Shunt Wiring Noob Questions

Looking at the Victron diagram for wiring a starter and house battery, here are my questions:

1) I don't need to monitor my starter battery. Can I assume that wiring only my house battery will be the same as wiring the battery designated as the Starter Battery in the diagram?

2) I read that if anything but the shunt cable is attached to neg side of my battery, the 712 will not work. I need to connect a Victron solar controller to the battery. How do I do that if I can't connect to the neg side of my battery? Does the neg on the solar controller connect to the load side of the shunt?


Thanks!

BMV Battery Monitor
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2 Answers
grim-reaper avatar image
grim-reaper answered ·

See this post, https://community.victronenergy.com/questions/5551/how-to-monitor-the-starter-battery-with-my-bmv-712.html?childToView=12601#comment-12601 your house battery will be the coloured in battery in the system, your starter battery is the greyed out one in the system but if you don't want to monitor the voltage on the starter battery then just leave all the connections as they are for that battery and don't connect the monitor lead to +B2.

If you connect anything else to the battery side of the shunt, the BMV will include that item's current drain in its calculations which will make them incorrect and may lead to issues with how you interpret the state of charge of your house battery. best not to connect anything but the negative side of the battery (bank) to that side of the shunt.

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fkfw avatar image fkfw commented ·

Thanks Mr. Reaper, but if I can't connect anything to the neg side of the battery, where do I connect the neg side of my solar controller?

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geomz avatar image geomz fkfw commented ·

@fkfw, keep in mind there are two sides to the shunt. What reaper is saying is don't connect anything to the battery side (it's labeled as such).

Everything else, your loads, your solar, your charger, inverter, anything, is connected to the other side; more than likely to a bus-bar that breaks out the negative taps, or in a simple install just stacked one lug atop the other.

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fkfw avatar image fkfw geomz commented ·

Thanks! That's what I thought - all the negative sides of my loads go on the load side of the shunt.

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geomz avatar image geomz fkfw commented ·

That's correct.

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sperry avatar image
sperry answered ·

Thanks for the valuable info everyone.


So, do I understand that the negative side of the shunt (not the battery side) essentially refers to the chassis ground throughout the vehicle? I'm not sure where to find 'Everything else, you loads, your solar, your charger, inverter, anything,' grounding point in the coach. Can I simply wire the negative side of the shunt to a good chassis ground?


Or, does it need to physically connect to the 'Everything else' ground points?


Thanks again!

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