question

gawan avatar image

Regular MPPT Power Loss ?

Good morning,

even if the overall line is perfect, I recognize a regular power drop of all of my MPPT on a regular bases every 10 minutes.

Here you can see my three MPPTs (orange, blue and darkblue) and their total (green) Power in Watt from 07:55 to 09:55.

In the exactly same time frame my Solaredge Converter shows a perfectly straight line without power downs.

Does anybody have an idea whats going on there and what I can do against it ?

BR

Gawan


MPPT - Solar Charge Controller
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @Gawan

What you're seeing there is the mptt's tracking, which they do every 10 minutes to optimize themselves. That should stop once they reach the Absorb/Float target(s) and they have no need to track.

Whatever kit you're using there certainly doesn't miss much, but the size of the graphed lines exaggerate it somewhat, as this happens very fast, but does seem to cycle a few times whilst tracking.

Sometimes the per-minute monitoring of VRM can pick this up (when the planets align), and it can also often be seen in the 'Trends' screen of Victron Connect, which updates more frequently.

It's probably an easy coding task for Victron to suspend data transmission during tracking, but I don't think they should. It is actually happening, and I reckon should be shown. What other makers do, I know not, nor care.

Edit/: What to do? Maybe not much you can. I'm personally reassured that the kit is working as designed, and I'm happy to see it.

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It never stops in my case ... it starts early in the morning and continues until late in the evening when sun goes down.

There is only one exception - I have limited the southside MPPT to 62A - as soon as the solar power reaches 62A the 10min drop procedure stops

But if this is the normal behaviour I have to accept it :)

Yeh. I checked an older post and see you're using MQTT, all good!

Just for fun, today I was looking at an hour-long Trends screen of a smartshunt. Every minute there was a very small but clearly discernable dip in Amps. This was late in Float so not many A overall, but it was on the minute, to the second. The only thing I can think of is the per-minute VRM logging. Was it picking up the power it was using to do that, or a circuitry thing?

For wonderment.. I'll wear it either way. :)