question

peak avatar image
peak asked

Best fitting MPPT controller

Hello,

I am planning to build a PV system with 16 modules in combination with MultiPlus 2 and an 48V battery.

My modules have the following specifications:

MPPT_Calc.JPG


My Plan is to connect 2 strings 4s2p to an MPPT 250/60-MC4, is that possible or do you suggest something different?


Thanks in advance!

MPPT Controllers
mppt-calc.jpg (39.2 KiB)
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2 Answers
JohnC avatar image
JohnC answered ·

Hi @peak

With just one 250/60, you will have effectively a 4S4P arrangement. 4x parallel strings of 10.71 Isc will exceed the total allowed of 35. So no, that's not possible.

A 250/85 or 250/100 have a 70A allowance, and either would work. The 100A model better suits your total solar wattage though. Still a little short in theory, but in practice would be a good match.

You could also consider more than 1 mppt, especially if your panel strings aren't all orientated the same way.


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peak avatar image
peak answered ·

Hi @JohnC,

thank you for your answer!

The panels have the identical orientation, but I could also imagine using two smaller MPPTs to have a better failsafe. Which MPPT would you recommend for a 4S2P then?
Thank you!

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JohnC avatar image JohnC ♦ commented ·
@peak

Probably a 250/60, a touch overpowered in this case. What does the calculator say, or are you just checking on it? :)

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