Solar Power (part 2) Panels

Solar power is very attractive to many RV users. I have not installed a solar system yet, but plan to on my next RV. As I have been reading not all panels are created equal.

There are a lot of choices when it comes to selecting the components you’ll need for your RV Solar System. Some components are inexpensive and some cost an arm and a leg. Solar for RV’s is one of those things that you get what you pay for!



It is best to do some research to find out what panels will work best for your needs. Most solar experts suggest that 32-36 cell panels work best for RV use.

Things you will want to know for a RV installation is how durable are they, will they hold up when you drive on unpaved pothole filled roads? How well are they sealed, will they stay water tight in a heavy rain storm? Does the manufacture offer a warranty on the panel if it is installed on an RV? What are actual users of the panels saying about them?

As a DYI kinda guy I was intrigued by the idea of making my own panels. I found Green Power Science and appreciated their videos. I’m not convinced this is the best practice for a RV application, but it will give you a better understanding of solar panels.

Photovoltaic cells work at peak performance when they are faced directly into the sun. Unfortunately for RVers it is impractical to install a tracking system to keep the panels facing the sun, and the best location to install is the roof. The reality is that a panel will only be in the best location a couple hours a day, so keep this in mind when you are calculating the size of panel or panels you need.

The best way to mount the panels is to use Z brackets. This provides the necessary clearance between the roof and the panel. Use nuts and bolts between the Z brackets and the panels, so that they can be removed easily. RV REPAIR & MAINTENANCE MANUAL

Solar panel performance is affected by temperature this is a good reason to leave space, at least 2″ between the solar panel and the roof of your RV. You may want to install a wind deflector on the front of the panel so the panel isn’t lifted off the roof while driving.

How have you installed your panels?

Solar Power (part 1) Battery Bank

My previous series was on understanding batteries and different ways to connect them. This series is a continuation, but moves into solar power set ups.

How do you know how much power you will need to generate and store for your RV needs? All appliances are rated in AC watts or amps. You can use the following formula to determine the DC amp hour draw for a 12 volt DC system:

(AC amps X 10) X 1.1 X hours of operation = DC amp-hours
(AC watts / 12) X 1.1 X hours of operation = DC amp-hours

This formula should be used to calculate the number of amp hours used between recharges for each appliance. Although a deep cycle can be discharged 80% without permanent damage it is best practice to allow for 50% cycling to improve battery longevity.  Do this by calculating the amp hour usage between charging cycles and then use a battery bank twice that capacity.


Sample Power Consumption in 12 volt DC Amp hours

Appliance Wattage 15min 30min 1hr 3hrs
light 100   2 4 8 24
blender 300 6 12 . .
coffeemaker 1000 20 40 80 .
Refrigerator 750 . 21 42 126
microwave 1500 30 60 120 360
vacuum 1100 22 44 88 264

How many batteries do you have in your battery bank?




Some of the information contained in this post is from the Bob Livingston RV Repair & Maintenance Manual 1998