question

bomadsen avatar image

Where is my power going?

Hi,


I have just gotten my setup up and running, and are currently testing the actual output of the solar array.

But I have found some discrepancies between what the SmartSolar, the SmartShunt and the MultiPlus are reporting.


In the "pure" charging scenario, the smartsolar reports 174W coming in, but the battery is only getting 147W.

In the AC discharge scenario, the smartshunt is reporting -2184w from the battery, but the multiplus are only outputting 1897w.


Where are my watts going? :)


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MPPT - Solar Charge ControllerMultiplus-IIsmartshunt
1618682435909.png (226.1 KiB)
1618682461792.png (576.2 KiB)
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2 Answers
seb71 avatar image
seb71 answered ·
In the "pure" charging scenario, the smartsolar reports 174W coming in, but the battery is only getting 147W.

All the devices you have consume some power (the inverter is taking the most of the difference).


In the AC discharge scenario, the smartshunt is reporting -2184w from the battery, but the multiplus are only outputting 1897w.

You have the above and in addition the inverting loses (a part of the energy is lost as heat).

Also, AC power values are less accurately measured.


Considering all these, your values are more or less correct.

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ripper avatar image
ripper answered ·

Also the PV Charger and the Multi is roughly guessing and overselling its abillity to deliver. The more the more inaccurate. But they do their actual job just fine.

If you want more acurate readings install more shunts which is close to perfect and maybe one for the AC side. You would however restrict power delivery for neat pictures, I cannot recommend.

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I actually like the idea of multiple shunts, but doing it with smartshunts would be quite expensive. The Simarine has a nice shunt module with multiple small(ish) shunts which would fit the bill exactly, I hope Victron will make such a module soon :)