Installing Flexible Solar Panels

March, 2011

If you live or travel in a fairly sunny area, one of the best things you can do is install solar panels on your vehicle home. Every day they silently create electricity to make our lives more comfortable. Most of us will just mount our panels directly to the roof of our vehicle. But what if your roof is small and already crowded so there is no room for any solar panels? Or, what if you want to park the vehicle in the shade so it doesn’t get hot?

One solution is to carry your solar panels inside the vehicle and set them out with a long cable in the sun when you park. And this works fairly well but it is quite a bit of extra work and the panels take up a lot of room inside the vehicle, something most of us don’t have.

Good friends of mine lived in a small Class B. There was no room on the roof to mount the panels and no room inside to carry a panel. They came across the Unisolar 68 watt flexible solar panel and knew they had found the solution to their problem. Since I had installed solar panels before, I offered to help them install their system and they agreed to let me take these pictures.

For some reason, we think that installing solar must be very difficult, but in fact it is remarkably easy. As you will see here, it is so easy anybody can do it!

In the past the Unisolar flexible panels have been very expensive, but as of now (I’m editing this in December of 2012) the prices have dropped dramatically. I just saw a 128 watt panel for $265. If you have any interest in them, go to Amazon.com and check out their prices. Just remember that they are very long and narrow, be sure they will fit before you buy them.

In the picture below you can see the main advantage of flexible solar panels. You can lay them out on the ground to collect sun, and then roll them up and store them under the bed for storage and travel.

Quick connects are what make it possible (pictures below). We used 50 feet of wire and put a quick connect on both ends. One end goes into the solar panel and the other goes into a cable which hangs down from below the bumper and goes to the solar controller. It’s very simple to set them out and then roll them up for storage. To be sure there wouldn’t be a voltage drop with that long a run of cable, we checked the voltage at the panel and at the end of the cable run and there wasn’t any drop of voltage.

The next step is to install the controller. You have to know where it goes to know how long the cables need to be going from it to the battery, and from it to the outside of the van where the quick connect will hang. In this class B there were a limited number of places to put it.

We used a Sunforce 20 amp controller, which is very reasonably priced but still has a digital display of the batteries voltage. You want to put it somewhere it’s easy to see so you can monitor the charge of the battery with a quick glance. Installation is very easy. On the back of the controller are two blocks that are clearly marked as “From the panel” and “To the Battery.” Both have a screw ready to hold a wire and each is clearly marked as “positive: and “negative.” All you have to do is crimp rings onto the ends of the cables, and screw them on.

From the controller we ran the wires down the corner and into the battery box. Here is the actual battery box with the battery out. The box that held the battery was rusted and the wood rotted, so we reinforced it with plumbers tape.

Here is the battery installed with the plumbers tape in place. The gray cable coming in from the right of the battery has a quick connect on the end of it that goes to the solar panel and goes up to the solar controller. Another cable leaves the controller and goes to the battery where it is hooked to the positive and negative posts. It is the cable coming in from the left of the battery.

To get the cables through to the battery, we had to drill a hole through the cover. You have to run the cables through the hole before you connect them to the battery or the controller–everybody always forgets that!

And that’s it, it really is very simple. If you can cut, strip, and crimp wires you can do this project!