currently running 16x250w panels in 4 strings
to update the panels to 405w i calculate I can only have 12 panels in 2 strings as to not overload the controller
are my calcs correct ?
asked
MPPT 250/100 250w upgrade to 405w panels
Without specs there is nothing to say about it..
You can use the mppt calculator
https://www.victronenergy.com/mppt-calculator
I have changed the design layout being considered Now 440w panels 4 in series 3 strings X2 chargers in parallel feeding to a Quattro 230/10000 Using the mppt calculator it seems its recommending 250/80 controllers @ 108% oversized & not the 250/100 which it says is 91% undersized witch I don't quite understand ( I have 2x 250/100 controllers presently) https://mppt.victronenergy.com#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
You need to select custom module, then put in the full panel specs.
Made no difference at all inputting custom panels info 250/85 108% oversized recomended 250/100 still 91% undersized
Sorry, I was expecting a difference. How are you getting the oversize undersized values?
But the calculator will allow a 130% oversize if you tick the box. Most of the day the sun is at a lower than optimal angle and there's a relatively short period when you can use max power. In many parts of the world panels rarely output the rated power.
But doesn't matter. As long as the calculator doesn't object, using a bigger controller does not affect performance, just costs more and gives you more headroom.
