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sharpharp avatar image
sharpharp asked

SmartSolar MPPT 150/85-MC4 VE.Can - How to connect panels the best way???

Hi,

I have a Victron Energy SmartSolar MPPT 150/85-MC4 VE.Can Charge controler which has 3x Sets of mc4 inputs connections possible.

At the moment I have 2x 400W Solar Panels (both solar panels face the opposite direction of each other ) and are connected to each other in Parallel and then come in on 1x MC4 Input on the Charge Controller.

I was wondering if my current setup is ok, or should I bring in the Solar Panel outputs seperately for each panel into the Charger Controller, so each has it's own Input on the Controller, effectively then i would be using 2x MC4 inputs on the Charge Controller.

I want to achieve the best setup for charging 12V batteries and loads connected to the batteries.

So in summary, do i keep panels connected in parallel or bring in seperately to their own inputs on the charge controller?

Thanks

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1 Answer
Kevin Windrem avatar image
Kevin Windrem answered ·

The 3 sets of MC4s are in parallel so the only difference would be the voltage drop in the wiring between the panels and the controller.

You would see an improvement by running separate charge controllers on each panel. With them in parallel, the panel receiving the most sun will shut down the other panel. With separate controllers each panel will remain active as long as there's enough sun on them.

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sharpharp avatar image sharpharp commented ·
Kevin,

Thanks for your reply,

SO what you're saying is, whether i connected the 2 panels together via a Y connector (so they are in parallel before i plug into the controller) and connect them as 1 INPUT... or if I plug the panels in seperately into the Controller on 2 INPUTS..... the bottom line is they are connected as Parallel either way and will cancel each other out?

If i put each panel into it's own Charge controller, then combine the outputs into the one Battery Bank, that would work and provide improvement over the current setup?

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Kevin Windrem avatar image Kevin Windrem sharpharp commented ·

Common wisdom is to use separate controllers for panels/arrays facing different directions so the tracking point can be optimized for each array. With the arrays in parallel, a single tracking point would probably not be optimal for either array.

I would experiment with the two panels into a single controller since you have it all now. Measure energy from one panel over one day then switch to the other panel. On the third day run both panels in parallel. Combining the numbers from the individual panels would give you an idea of what you could expect from separate controllers. The third day measurement can be compared with the combined energies from the single panel runs. If the difference is great then a second controller might be worth the investment.

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