MPPT doesn't get all panel wattage

DIY
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1

I have a Victron MPPT 150/85 connected to 2 strings of 3 panels each of 340W to 355W. Each panel is about 40Voc and 10A, so both strings of 3 panels are about 120Voc 10A 1020W. They are Connected in parallel.

I just noticed yesterday from the logs “Solar Charger PV Yield” That the Wattage has never went over 758W. This doesn’t make any sense to me, with 2040w of panels, shouldn’t I be getting much higher then this since Jan 1 2025?

I tested one string by removing the parallel connectors and the wattage was still low. Connecting just one panel still only gives me about 200w range withing the 340w that I should have.

Any idea what can cause this?

2

Maybe you didn’t had enough loads for the MPPT to produce more than that?

Anyhow, the specs for panels are in ideal conditions, the real output you can expect continuously is about 75% of that.

3

Have you tested the short circuit current and the open circuit voltage of your panelsin strong sunlight and compared these with the panel specs to see if the panels are working. The other issue could be a poor connection somewhere causing voltage drop.

Orientation of the panels can have a large impact on performance , there are many on line calculators that will predict performance if you input panel location and orientation.