question

jk79 avatar image
jk79 asked

SmartSolar 100/50: "Solar Power" drops to 0 for 5 sec, every 39 sec

After switching from a "Victron Energy SmartSolar MPPT 75V 15 Amp" to a 100V/50A one, in preparation for a larger Solar panel (from 100W/18V to 400W/36V, with the battery still remaining at 12V), I have noticed a very weird behavior in the Android app, Trends -> Solar Power -> Live view, that did not happen with the 75V/15A version:

Every 39 seconds the "Solar Power" drops to 0 for 5 seconds, and then returns back to whereever it was before.

If this is somehow "by design", then this seems like a good way to reduce the efficiency of the solution (losing 5/39 = 12.8% of the possible available solar power).

Neither a google search nor a quick search here on the forums seem to be referring to the 39 seconds, thus decided to submit a new post.

smart mppt
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3 Answers
jk79 avatar image
jk79 answered ·

Here a screenshot. Forgot to mention, that during this whole time the MPPT controller is in Bulk mode, and the battery is a small 12V/30Ah LiFePo4 battery, with the correct (uncustomized) "Battery Preset" set.screenshot-20221031-142350-anonimized.jpg


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klim8skeptic avatar image
klim8skeptic answered ·

It would seem that your mppt is keeping your battery at a stable voltage, by regulating the array output power.

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jk79 avatar image
jk79 answered ·

Well, then that behavior is not in-line with the "Battery Preset" setting, and the MPPT charger being in Bulk mode. With the settings being: Absorption voltage: 14.20V, Float Voltage: 13.50V

And I have seen this working properly with the 75V/15A version, where it charged the battery properly to 14.2V, before moving over to Absorption, and eventually Float.

PS: just confirmed with a clamp meter, on the solar panel output lines, that the current drops to 0.00A for those 5 seconds, repeatedly - thus this is not just some incorrect reading / interpretation by the app - this is what the MPPT controller is actually doing.

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