How to Connect Solar Panels in Series and Wire in Parallel

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Learn How to Connect Solar Panels in Series and Wire in Parallel

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Solar power is an excellent source of energy for your RV or camper. However, to use it effectively, you need to know how to wire your solar panels in the right configuration. In this article, we will guide you on how to wire solar panels in a series-parallel configuration. We assume that you have already watched our previous videos on basic electrical skills, such as how to make MC4 connectors, check voltages using a multimeter, wire solar panels in series, and wire solar panels in parallel.

Materials Required

  • Four 100-watt rich solar panels
  • MC4 connectors
  • MC4 combiners
  • Wires
  • Red heat shrink
  • Cardboard
  • Fuses (if needed)


  1. Determine Positive and Negative Wires Using a multimeter, identify which wires are positive and negative for each solar panel. Mark the positive wires with red heat shrink and cover the panels with cardboard to avoid working with live voltage.
  2. Wire the Panels in Pairs in Series Take the outside pairs of solar panels and wire them in series by connecting the positive wire of one panel to the negative wire of the other panel. Repeat this process for the other pair of solar panels.
  3. Wire the Series Wired Strings in Parallel Next, take all the positive wires from each series wired string of solar panels and attach them to a two-to-one MC4 combiner. Then, take all the negative wires from each series wired string of solar panels and attach them to another MC4 combiner. Finally, attach each positive and negative MC4 combiner to the wires that will go through the roof and connect to the charge controller.
  4. Add Fuses (If Needed) If your array needs fuses, attach the MC4 fuses to the positive MC4 connector between the combiner and the panel wires. You can use our free wiring diagrams to determine when to use fuses.
  5. Repeat the Process for More Panels If you have more than four panels, the theory is the same. For example, if you had six solar panels, you could wire them in three panels in series with the two series strings in parallel, or you could wire them two panels in series with the three series strings wired in parallel. If you had 16 panels, you could do series strings of four panels with the four series strings wired in parallel.
  6. Note About Identical Series Strings All series strings must be identical. For example, you cannot wire five solar panels in series-parallel because it’s not recommended to have an array with a series string of two panels wired in parallel with a series string of three solar panels.

Why Wire Solar Panels in Series-Parallel?

Wiring solar panels in series-parallel allows us to keep the voltage from our solar panel array high enough for the MPPT charge controller to do its job effectively, but low enough to stay under the max voltage rating of the charge controller. It also allows us to keep the solar panel array amps low enough so that we can effectively use smaller wire throughout the entire array without worrying about excessive voltage drop.


Wiring solar panels in a series-parallel configuration is not complicated, but it requires careful planning and execution. By following our instructions and using the right materials, you can successfully wire your solar panels for maximum efficiency. Don’t forget to share this article with anyone who might benefit from it and leave your questions in the comment section below. Subscribe to our channel for more DIY camper building tutorials.

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