If you already have solar panels on your RV roof but want more power when you're parked, you’re not alone. Many RVers are adding portable panels to boost battery charging while boondocking or parked under trees.
The easiest and most flexible way to do this is by using a separate solar system for your portable panels. You can connect another charging system up to your battery without affecting the existing charging system(s)--meaning your battery could get charged by the panels on the roof and the folding panels at the same time.
In this guide, we’ll walk you through how to connect two Shade Stopper 100W Folding Solar Panels to your RV batteries using their own dedicated charge controller — no need to touch your existing system.
Why Use A Separate System?
Instead of trying to combine your portable panels with your roof setup, a dedicated charge controller for your folding panels:
- Keeps things simple
- Avoids voltage mismatch issues
- Works with your existing battery bank
- Allows flexible placement in full sun, even if your RV is in the shade
What You'll Need
- Shade Stopper folding panels. For this example, we will be using 2 folding panels, but you could use more or fewer if you like.
- A charge controller capable of charging your battery voltage and type (Lead Acid, Gel, Lithium Ion, etc) at 200W. We recommend the Victron 75|15, as it is high quality with a good app, but there are lots of good options out there. Just make sure it can handle up to 48 volts on the input and 9 amps on the output (for 2 shade stopper panels in series).
- You might need some adapters and extension cables, such as this MC4 Extension cable for the solar input, and this cable with ring connectors to connect to your battery. It just depends on the exact connections your battery and charge controller require.
How To Set It Up
Here is a basic wiring diagram:
- Connect the battery you are going to charge to the charge controller Battery Output. Follow the charge controller instructions for connection and configuration. Be sure to select your battery voltage (usually 12V) and chemistry (lead acid, lithium ion, etc.). Your battery will already have some connections on it: some inputs and some outputs. Connecting this system to it will not interfere with the existing connections.
- Now let's connect the solar panels. Connect the MC4 adapters that come with each folding panel to the built in cable.
- Connect the RED (+) of one panel to the BLACK (-) of the other, like this:
- If necessary, use an MC4 extension to reach the Charge Controller. Be sure to connect the positves/reds together and the blacks/negatives together. (This might be trickier than it sounds because the MC4 connectors have to match.)
- If you are using the Victron 75|15, the PV input requires bare wire. You can either cut the ends off the MC4 adapters (or extension), or you can purchase this cable with bare wires for the Victron connection. Follow the charge controller's instructions for connecting the wiring.
That's it! now you can setup the panels in the sun and watch your battery charge up!
You can disconnect the system wherever is convenient in order to make it portable. For example, you could permanently affix the charge controller to the battery housing, and leave the input MC4 cables connected, and then just plug the barrel cables in when it's time to use the portable panels.