DC current or energy measurement with Venus GX

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svenr asked Oct 20, '20

DC current or energy measurement with Venus GX

In an upcoming project there will be a need to measure DC current up to about 90 A also from sources that are not controlled with Victron equipment and/or to loads. Does anyone know how to use a DC current sensor or DC energy meter with Venus GX/VRM? I would like the system owner to be able to monitor at least the DC current (A), but power (W) and/or energy (kWh) would be even better.

I have seen that some AC energy meters are supported by Victron (https://www.victronenergy.com/live/energy-meters:start), but I can presently not find any DC energy meter listed there.

Example of DC energy meter, which seems to be available e.g. with Modbus TCP communication: https://www.measurlogic.com/product/dts-dc/

Example of USB current sensor: https://calibike.com/product/calisense-usb-acdc-current-sensor/

Example of current transducer that I have good experience of from other applications: https://www.seneca.it/en/linee-di-prodotto/energia-e-misure-elettriche/trasformatori-di-corrente-serie-t201/t201dc/

Or could anyone consider to add such functionality to Venus OS, e.g. an an open source project (https://www.victronenergy.com/live/open_source:start)?

Venus OS Venus GX - VGX dc system

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Answer 1 · 2020-10-20T11:28:07Z

Guy Stewart (Victron Community Manager) answered · Oct 20, 2020 at 11:28 AM

The BMV and SmartShunt not perfect for an individual DC load or charge measurement tool, as it is a battery monitor and expects to be installed in a very specific, system level way.

But if you understand those nuances, and can ignore the state of charge information, it will probably more or less do what you want out of the box.

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svenr commented · Oct 20, 2020 at 11:44 AM

Thank you for the answer. We are planning to use one BMV for the battery. Would be interesting if we could use another one for DC load or charge measurements and e.g. display only the current. Could the display from Venus GX / VRM be tweaked in such a way?

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bathnm svenr commented · Oct 20, 2020 at 11:57 AM

I have done something similar, and have a smart shunt monitoring some loads. This doesn't show up on the main Dashboard screen, but can be seen in the advanced section.

This is how I configured the Smart Shunt

This is what I see on my Cerbo

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svenr bathnm commented · Oct 21, 2020 at 07:04 AM

Great explanation - thank you! I suppose it makes sense to wire the shunt so negative current corresponds to a load

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bathnm svenr commented · Oct 21, 2020 at 10:42 AM

@svenr the Victron shunts only go in the negative side. They are not designed to go on the positive side, but yes it does show the load as negative which is good.

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svenr bathnm commented · Oct 21, 2020 at 11:31 AM

Yes, I understand they are designed to be used on the negative pole. However, the current measurement must be bidirectional, because a battery can be charged or discharged (and thus current is shown as + or - depending on flow direction)

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bathnm svenr commented · Oct 21, 2020 at 01:57 PM

Ahh yes of course. I installed so that the load was on the load and battery side is towards the battery, even though there is charge sources between the two shunts. This means that I know what my load is and it is negative, and always will be, as it is drawing.

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