question

scorpion avatar image
scorpion asked

MPPT max solar panels

I currently have a Victron MPPT 250/70 with 2x MC4 connectors.

I also have 8x 410Watt Canadian Solar panels connected as 2 Series of 4

In winter the solar panels does not generate much power as expected but in summer it runs great.

Can I add another 4x 410 watt Canadian Solar panels to help boost my winter Power Generation without overloading the MPPT in Summer as the total is 4920Watt and the Specs sheet shows only 4000Watt @ 48volt battery system. The Inverter is a Victron Multiplus II GX 48/3000/35 and I have 5 US2000 Pylontech Batteries I am trying to charge.


Do I need another MPPT or will the 250/70 just reduce Solar panel power in summer.

MPPT Controllers
2 |3000
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JohnC avatar image
JohnC answered ·

Hi @Scorpion

That should be ok, the mppt will just throttle as required.

The thing to watch is the 35A Isc limit on the 250/70. If your panels were say 10A Isc, then you could have 3x strings (4S3P), but not 4 (4S4P).

Check the panel specs first..

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scorpion avatar image scorpion commented ·

I will not go to 4S4P.

Only going for 3S4P as I am running for 200Volts from Panels.

My roof does not allow for 5 Panels in Parallel.

I am going to use a Professional for installation but just wanted to check myself on the facts. The MPPT Throtteling back is awesome.

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JohnC avatar image JohnC ♦ scorpion commented ·

@Scorpion

Just checking what you mean by "3S4P". Or a typo?

You likely have 4x panels in each Series string (4S), 2x strings of those now (2P), and want to add another string in parallel, so I call it 4S3P. Just so we're on the same page.. 3S4P wouldn't do..

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scorpion avatar image scorpion JohnC ♦ commented ·
My Apologies. I mismatched

Yes 4S3P

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