December 9, 2021

Series or Parallel connecting Solar Panels: The Definitive Guide for Mobile Solar Applications

So how should you connect your own panels?
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This article is geared towards people wondering if they should be connecting their solar panels in series or in parallel; specifically for mobile applications. If you’re wondering about how to connect your panels when mounting them on your Van, RV, Skoolie, Boat, Truck etc, then this is the perfect article for you.

First off, let’s understand the difference between series and parallel as they both have distinct advantages.

For series connected solar arrays you get the benefit of a higher voltage and a lower amperage. This will translate into less wire loss and a higher efficiency. So, in a series circuit you add up the voltage of each panel to get the overall voltage of the array but the amperage of the overall circuit stays the same. Anything in a series configuration, whether its 2 or 8 panels you should consider one large panel since they will all act as one unit. They all need to be the same amp rating same voltage rating, and they all need to have the same gauge of wire connecting them.

Parallel connected solar arrays have a huge advantage as well, specifically for vehicle applications. In a parallel configuration each panel will produce power on its own. So if one panel goes bad, or is damaged, or is just in the shade, the rest of the solar array will continue to product power. In parallel connected arrays the voltage stays the same but you add up the amperage. It's the opposite in that way to series connected panels.

So how should you connect your own panels?

There are some important things to consider here. In a mobile application there will be many times that your solar array might be in a shaded area. If half of your solar panels are shaded then half of your panels won’t be producing any electricity and anything connected in series with those panels won’t work either. This is much more likely to happen with a mobile solar array because you're constantly on the move and in new places.

The benefit of a ground mounted array for example is that you're able to plan the perfect angle for your panels, take out any obstruction that could block out sun, etc. Therefore it seems like maybe a parallel solar array makes the most sense.

However, something else to consider is the limited roof space for most mobile applications. Since for example, a van roof has a hard limit to the amount of panels you can put on there it makes sense to value efficiency above all else in order to make the most of the limited space. Therefore it's tempting to connect all your panels in series.

So, what should you do? The answer is actually that you do both; parallel and series. Let us explain.

By connecting your panels in series and then parallel connecting the series you will get the benefit of higher the efficiency and the ability to have separately functioning panels. For example, if you have a 400 watt set up, our suggestion is to series connect two panels and then parallel connect everything together. This way you can get the benefit of both series and parallel. (See photo below)

This scales up very nicely as well; a 600 watt system would have 3 sets of series connected panels and all of the series would be parallel connected. If you have an 800 watt system then you have 4 sets of series connected panels parallel connected and so on and so forth. (See photo below)

Another thing to remember is that most solar panels for 12 volt systems give off around 20-24 volts. If you series connect two of them you’ll be getting 40-48 volts which is more than enough if you’re running 10 gauge wire. If you put more than two panels in series then 10 gauge wire is not enough. Series only increases your efficiency as much as the wire can handle. 200 volts going through 10 gage wire won’t be much different than 40 volts going through 10 gauge wire because of the wire loss.

We hope you found this article helpful. If you have other questions or concerns, feel free to check out our website shopsolarkits.com or e-mail any questions to info@shopsolarkits.com. You can also always call in at 877-242-2792 as well.