Extra wires to sense current on lynx shunt

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mattguy asked May 6, '22

Extra wires to sense current on lynx shunt

Hey all I had no hits the other day asking about the reference voltage of the lynx shunt. I tried asking Victron directly but got the answer that the lynx shunt uses a range of voltages to sense current. Which doesn't make sense to me, but I'm no EE.

My question is then, does anyone know if it's possible to add an extra current sensing device to the circled locations in the attached photo on the shunt. Essentially using the shunt as a normal 'dumb' shunt for the device I'm trying to hook up? Thanks for any and all help.

lynx shunt

lynx-shunt-vecan.png (6.3 MiB)

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kevgermany answered · May 07, 2022 at 03:52 AM

Shunts work on ohm's law.

Resistance of the shunt is known. Voltage across the shunt depends on current flowing through it. Circuitry in the unit measures the voltage across the shunt, calculates current and reports it. Hence the varying voltages reply.

It's not clear what you're trying to do but you must have a low resistance/high current draw. You should not connect anything across the internals of the shunt. You risk fire as well as breaking the shunt. If it does continue working, chances are that your actions will invalidate any shunt readings.

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Modifications Space

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Answer 1 · 2022-05-09T07:32:52Z

mattguy answered · May 09, 2022 at 07:32 AM

Thanks for your reply.

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Answer 2 · 2024-01-19T12:04:50Z

kaikane answered · Jan 19 at 12:04 PM

This post is a bit old but I'm not sure I understand the answer to this question and hope to clarify the question here. If there is a non-Victron product that needs battery shunt voltage &/or current data, why is attaching sense wires to the Kelvin connections on the shunt (as the Lynx BMS is doing here in this photo) a problem? While that same voltage & current data may be available on the DVCC, for non-CAN bus devices that need this data it would seem this Kelvin connection on the Lynx BMS is the only simple option. Any comments?

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