Bryan Appleby, aka the Xtreme Boondocker, reveals hard-earned lessons on RV solar panel systems, debunks battery and solar myths, and offers some battery bank best practices.
There was that sound again; “Knock. Knock..” on my truck camper door. Getting up from my dinette, I see two men smiling up at me, one with a note pad and pen. This is something I have experienced often, since installing the solar panel systems on my rig.
Upon seeing my rig, people frequently approach me and ask lots of questions about solar systems and battery banks. What these folks don’t realize is that many RVers don’t need a solar panel system and would be better advised to upgrade their battery banks. I often start my conversations with this point, as I will cover here.
The question most folks ask is, “Is a solar panel system a cost effective option for truck camping?” In other words, are the gains from solar panel systems worth the cost, and required holes in your truck camper roof?
In my experience, the answer in most cases is no. All too often, truck camper owners have not realized the full potential of their existing battery banks. They overlook the simple upgrade of bigger and better batteries, and aren’t properly charging, monitoring, and maintaining the battery bank they currently have.
With this article my objective is to help you answer the question, “Is solar the best option for the way I use my truck camper? Or, should I just upgrade my battery bank?” Let’s begin by dispelling some common solar myths that I hear during my travels.
Myth #1: RV Solar Panels Provide Their Rated Power
Logic dictates that a 100-watt solar panel would provide 1,000 watts of power over the course of a 10 hour day of sunlight, right? Unfortunately, this is not the case. Most solar panels only deliver about 60%, or less, of their advertised wattage on a daily basis.
Here are the most common reasons why this happens:
1. Changing Seasons: The angle of the sun, and thus the solar charge potential, changes throughout the year. For example, the peak summer sun offers more solar power potential than the depth of winter sun.
2. Daylight Hours: The length of daylight also changes throughout the year. For example, there are more daylight hours in the summer than in the winter. In the summer you’ll not only enjoy stronger sunlight, but longer exposure to that sunlight.
3: Shade: Potential solar power is lost to cloud shade, tree shade, building shade, and physical obstruction shade from roof installed features (like air conditioners) that block sunlight from reaching the solar panels. It’s amazing how many solar panel systems are blocked by objects on the RV roof itself.
4. Cable Length and Quality: Potential solar power is lost to resistance from the length, size, and quality of cable used for the solar panel system and battery.
5. Solar System Quality and Type: The quality and type of solar panels and solar controller also affect the ability of the system to charge your camper batteries.
6. Battery Bank Quality and Type: Finally, solar power can be lost from the age, size, and overall condition of the camper battery bank. More on this later.
Myth #2: More Solar Panels Are Better
Above: The solar panel set-up and battery bank on Bryan’s truck camper rig – click to enlarge
Upon seeing my set-up, some folks want to jump to the conclusion that more solar panels means more solar power. While technically true, solar power is worthless without a corresponding battery bank that can take full advantage of the power that the panel system can generate.