question

Karl Laasik avatar image
Karl Laasik asked

Difference between SmartShunt and Multiplus-II charging readings

Hi dear Victron community!

I have a three phase AC-out-coupled system with Multiplus-II, CerboGX, SmartShunt, Lynx distributor and battery balancers. Battery pack is 48V 600Ah made from 12 pcs of 12V lead acid GEL batteries. Pictures attached. I am interested why I get so different charging values from SmartShunt and Multiplus. The difference is usually around 100 W. And this is 70% difference when battery is full.

The SmartShunt shows correct power when calculated with a simple formula N=UI but the Multiplus power is much higher. Can somebody think of any reason why that is?

Thanks in advance


Karl

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Multiplus-IISmartShuntAC PV Coupling3 phase
1641986919171.png (51.4 KiB)
1641987231829.png (556.8 KiB)
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2 Answers
Alexandra avatar image
Alexandra answered ·

@Karl Laasik

The multiplus units have no shunt for measuring accurately. So it is more of an estimation based on clever maths rather than a measurement. Length of cable to the inverters can affect voltage readings etc can have an effect on its accuracy.

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Karl Laasik avatar image
Karl Laasik answered ·

@Alexandra

Thank you for the answer. Good to know.

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