This week’s video is really about two things: the differences between wiring your solar panels in series vs. parallel, and why I had to rewire mine.

If someone who had never seen an automobile before asked me to explain how it works, there are a couple of different ways I could answer. The simple explanation is that you put gas in the gas tank, use the pedals to stop and go, and steer with the steering wheel. Or, I could dive into spark plugs and carbonators and fuel pumps, all of which are essential to making a car go but none of which are really important if you just want to drive.

I tend to think of solar panels the same way. When people want to add a solar panel to their RV, van, or camper, they really don’t want to talk about inverters and converters and charge controllers. What they really want to know is, “how do I charge my batteries for free using the sun.” That’s the level I operate on — and yeah, while you have to know a couple of technical-sounding terms, I don’t think most people want to learn about this history of electronics when adding a solar panel to their vehicle.

The reason conversations around wiring multiple solar panels in series vs. parallel get so confusing is because people explaining it want to talk about spark plugs and carborators and fuel pumps. I don’t. I just want to connect two solar panels to the same power station. If that’s you, then you’re in the right place.

I go over this in the video but sometimes it’s easier to explain with written words. Every solar panel comes with two cables, one positive and one negative. Connecting them to a power station is pretty simple. Almost all power stations support solar charging and none of them have an input that looks like the cables coming off the solar panel. Solar panels have what are called XT60 cables, so you’ll need an XT60-to-“something” adapter, that “something” being whatever input port your power station has. Many of them have these little rectangular ports called MC4 ports but others have a small round barrel connector. Amazon literally sells every kind of adapter so the only hard part is knowing which one to buy.

If you decide to add a second solar panel like I did, you’ll quickly realize there’s only one solar charging input port on your power station. Now you have to figure out a way to “combine” the cables coming out of two panels so that they can both go into the power station. That’s where series vs. parallel wiring comes in.

Wiring two panels in series is just like it sounds. Run the positive cable from panel #1 to the power station, connect the negative cable from panel #1 to the positive cable of panel #2, and run the negative cable from panel #2 to the power station. The entire thing is now running in series — it’s a big loop. The upside of wiring panels this was is that no additional connectors or parts are needed. The downside is that the two panels are now acting as one big panel. If one is covered by shade or gets damaged, the whole thing will be affected.

Wiring two panels in parallel means each panel will work independently of one another. The way this is done is by using a Y-shaped cable splitter. You’ll need two of them, one to connect the positive cables from both panels and another for the negative cables. Then you run those other ends into the power station. Because they’re working independently in parallel, if one panel dies the other is not affected. The downside to this configuration is that you have to buy some additional cables.

There’s a simple equation that’s handy to know: Volts times Amps equals Watts. V x A = W. Just like any algebraic equation, if you know two of those numbers you can easily find the third.

In this video I’m using a 200 watt solar panel. The particular panel I own produces 32v and 6.25 amps and when you multiply those numbers you get 200 watts, which checks out. Here comes the slightly confusing point. When you combine two panels, we know the number on the right hand side of the equation is going up to 400 watts. The question is, which number on the right is going to double to get us there? The answer depends on how you wire your panels together. If you wire them in series, the volts will double. If you wire them in parallel, the amps will double. Why? I don’t know. Understanding why gets into carbonators and spark plugs. For all practical purposes, all you need to know is, that’s how it works.

This brings us to the core of this episode’s problem. I recently swapped out my AllPowers R2500 power station for a Bluetti and when I did, my solar panels stopped charging my power station. The reason has to do with the difference between those power stations. The solar input jack on the R2500 can handle up to 150v and 20a. The Bluetti Elite 200 V2 can also accept 20a, but only a max of 60v.

Because I had my solar panels wired in series, the 32v was doubling to 64v, which was too much for my Bluetti. By rewiring them in a parallel configuration, I was able to keep the volts at 32v and double the amps from 6a to 12a — still within the capabilities of the Bluetti.

It all sounds more confusing than it is and I hope the video explains it better than I just did. The real takeaway here is that there are advantages and disadvantages of wiring two solar panels together in series or in parallel. It all depends on your needs.