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abeness avatar image
abeness asked

SmartSolar 100/30 Pmax discrepancy between History and Trends

Hello, All. Trying again after the site ate my first try.

I've noticed a significant discrepancy between the Pmax as reported in History and that displayed in the graph in Trends. Today, for example, History reports Pmax as 95W, while the largest Solar Power value displayed in Trends is 82W. Screenshots below for reference. I'm running the latest firmware, 1.61, but this discrepancy occurred in the last version, too.

I've noticed that History does not immediately update to the highest wattage reported in Status. I've assumed this is because incoming wattage must meet some specified minimum duration to be considered significant enough to report as Pmax. The Trends graph, however, displays the fluctuations. This is the opposite of the behavior I'm reporting here. (If it were consistent, I would expect Trends to show 95W at some point for however brief a moment, while History might only report Pmax of 82W. Except that would probably be even weirder!)

Have I missed some consideration? Perhaps Victron could take a look at their reporting algorithms to ensure that they are consistent.

Abe

history-pmax-95w-reported.png

trends-near-pmax.png

trends-pmax-82w.png

MPPT SmartSolar
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2 Answers
Thiemo van Engelen (Victron Energy staff) avatar image
Thiemo van Engelen (Victron Energy staff) answered ·

Hi @abeness

The 30 day history records the maximum PV power during that day, even when that only lasted for a second. However, our implementation of trends performs averaging over a sample interval. So when the interval between two samples is 30 seconds in the trend graph, the trend graph will show the average power over that interval. This means that the trend graph will only show the same maximum when it was at its maximum for the complete sample time.

Kind regards,

Thiemo van Engelen

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abeness avatar image
abeness answered ·

Hi, Thiemo. So sorry I'm only responding a year on: thanks for this clear explanation of your implementation.

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