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scalcon-riccardo avatar image
scalcon-riccardo asked

SMART SOLAR MTPP 250/60 MC4 - HOW TO CONNECT SECOND STRING WITH DIFFERENT PANELS

Good morning,

I have MTPP 250/60 MC4 solar charge controller (has input for 2 strings in MC4)

Currently I have connected 3 panels in series of 330 Watt each PANASONIC - VBHN330SJ53 on a string VBHN330_325SJ53_IT (I miei pannelli).pdf( where they reach a maximum voltage of about 210 Volt

I need more solar energy but due to space constraints I can now only add 3 more panels in series

100 Watt each SUN PEARL 100 scheda-tecnica-1900371-phaesun-sun-pearl-100-pannello-solare-monocristallino-100-wp-12-v.pdf

where they could reach the maximum voltage around 66/67 V

Can I connect the second 300 Watt string to the currently free Victron MTPP 250/60 MC4 string ???

Is solar controller able to optimize, manage and add the two different powers coming from two different strings?

Thanks for your opinion

Solar Panel
vbhn330-325sj53-it-i-miei-pannelli.pdf (1.4 MiB)
scheda-tecnica-1900371-phaesun-sun-pearl-100-panne.pdf (599.6 KiB)
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3 Answers
pwfarnell avatar image
pwfarnell answered ·

The MC4 connectors are in parallel, there is only one controller. You will not be able to run the 2 sets of panel together due to the vastly different voltages. The 300W string will probably end up having the 200V output voltage forced on it so it will not deliver any power. The 2 parallel strings need to have similar voltage.

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scalcon-riccardo avatar image scalcon-riccardo commented ·

I thank you for your answer, then I will have to use a second MTPP 100/15 or 100/20 regulator for the second string; my happens when it is this ... what comes to the same battery 2 currents from 2 regulators differentiate? Surely the most powerful string regulator will deliver more anperes .... it can happen that the smaller regulator sees a high charge voltage and then gets "cheated" and doesn't charge ????

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klim8skeptic avatar image
klim8skeptic answered ·

Perhaps the op could squeeze another panasonic panel on their roof?

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kevgermany avatar image
kevgermany answered ·

Second MPPT I think

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