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above-the-arctic-circle asked

What mppt should I use

We are building a off grid system with solar panels in four different directions.. System use 48v Pylontech batteries, Cerbo CX, MultiPlus-II 5000VA, generator, + some mppt, but what MPPTs should I use?


The first Building has four solar panels on the roof and two upright on the wall. The second building has nine panels on the roof and three solar panels upright on the wall.

Cabin is located so north that the roof is covered with snow for four months. That is why we also install panels on the wall.

Solar panels 285w, Voc 39,0V, Isc 9,48A

cerbo gxMPPT SmartSolarmppt charging
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2 Answers
Al avatar image
Al answered ·

Have you seen the Vitron MPPT claculator?

https://www.victronenergy.com/mppt-calculator

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above-the-arctic-circle avatar image above-the-arctic-circle commented ·

The main question is, installing wall-mounted solar panels with a different charger or with diodes in the same charger as those on the roof?

Or, do we get a better result by putting in four chargers?

So my mistake, the question is; which panels would I put in one charger?

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Al avatar image
Al answered ·

I think if you can afford it go for 4 x separate controllers maybe PWM makes it more affordable if that's a priority, or try to put the four arrays together into two or three. But It's not a good idea to mix different orientations on the same controller.

So if possible four x MPPT controllers will give you the best gain, but if the two roof arrays and two wall arrays are identical in angle and have no shading, then maybe they could be treated as just two arrays ( roof / wall) if the cabling is easy between them.



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