Multiplus DC voltage input monitoring v‘s BMV 712 smart shunt

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bazil asked Jun 25, '23

Multiplus DC voltage input monitoring v‘s BMV 712 smart shunt

The Multiplus monitors the DC input voltage and will shut down the inverter; let‘s say this value is 10.5 V

The BMV 712 with smart shunt has a low voltage relay setting of equally 10.5 V. The said relay controls the Multiplus.

There is a discrepancy between the two devices hence the Multiplus may assume a low voltage scenario whilst the BMV continues with the relay open.

Do you agree the BMV measurement is more accurate and that I can set the Multiplus DC low voltage to reflect this difference?

Many thanks

battery system voltage

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Answer 1 · 2023-06-25T14:43:08Z

Alexandra answered · Jun 25, 2023 at 02:43 PM

@Bazil

The BMV can have a better idea of what the battery is actually since it is installed right by it.

But the inverter can only invert with what voltage its terminals are supplied with.

So if there is a large discrepancy then you need to change your DC set up. Maybe use larger cables or check crimps connections and fusing/breakers there should not be a massive voltage drop.

If the battery bank is 10.5v but the inverter is reading much lower (for example 9v) it will shut down as the voltage is too low regardless of the bank voltage.

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