question

adam-martin avatar image
adam-martin asked

Smart Shunt - Specs for longer Aux voltage monitor wire?

I need to run a longer wire for monitoring Aux (starter) battery voltage. I did find a thread linked below saying it's low voltage which I would expect, however there are no specs available anywhere to confirm this. Does anyone know the actual specs on what is going through the Smart Shunt Aux port so I can appropriately size the wire over a ~15 ft total length? Cheers!

https://community.victronenergy.com/questions/125993/possible-to-use-a-longer-red-wire-for-the-smart-sh.html

SmartShuntwiringvoltage
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2 Answers
wkirby avatar image
wkirby answered ·

Input impedance of the Aux input of my BMV-712 is about 320kΩ, I can't imagine the SmartShunt is much different given that they can use the same accessories.

All you need is the resistance of your length of wire and system Voltage, then you can calculate what the Voltage drop over your wire will be.

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pwfarnell avatar image
pwfarnell answered ·

The Smartshunt manual states that the current draw of the device is lass than 1mA and the current draw for the aux connection for voltage will be much lower than this, you are talking microA. Just extend with the same size wire.

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