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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.

MPPT SmartSolar
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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


screenshot-20221031-142350-anonimized.jpg (223.4 KiB)
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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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chebanov avatar image chebanov commented ·
I have the same issue on MPPT 100/20. The only way that I found that helps to stop this was to reduce the charge current on mppt from 20 to 7A (which is equal to my load). But I'm wasting the exessive solar power. Looks like the extra power had nowhere to go (feed-in disabled and batteries are fully charged) and controller fall into a "safe mode". I'd like to follow your question and hope that someone could help us.
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