Outside Supply is constantly working on adding more information to our RV solar information guide. This includes arranging the information in an easier-to-follow format. Here is some basic information that is covered in this document:
- Sizing your RV solar kit
- Choosing a battery bank size for your RV
- Battery choices and types for mobile solar arrays
- Proper mounting for RV solar panels
- Determing the amount of power your panels will produce
- Matching a power inverter to your solar setup
- Proper UV protected wire size for your solar kit
- MC3 or MC4 Cable Conntectors for solar panels
- Proper wiring of charge controller
- Portable versus fixed solar kits
- Silcone Sealant for installing solar panels on RV roof
- RV Grade solar panels versus residential panels
- Solar budgeting
- Choosing the right solar system for your RV
- Are lithium batteries a good choice for solar?
- Operating your solar setup off grid
- Conversion Camping Van Guide
Getting started in RV solar:
More power with your RV will allow you to extend your stay in the wilderness! There are several choices of power available to RV'ers.
These power choices include the following power options:
- Site-Based Power (Grid Power) -- Usually found only in improved parks and sites; cost is between $12 and $300.00 per night for sites.
- Generator Power -- This is a great short-term, offgrid power source. Running on a generator has several issues to consider:
- Fuel Cost
- Generator Service Schedule
- Generator Bans or Schedules
- Battery Power -- This is a great way to run 12-volt items in your camper. A power inverter can allow the running of 120 VAC devices in your camper. This is where a solar panel charging system can provide remote charging for your off grid RV application.
This article will focus on 12-volt solar panel charging systems for operating your RV off grid. Any time we discuss solar panels for your camper, please remember with areas that have less sun will require more solar to achieve the same charging levels. When discussing solar panels for your RV, it is best to start with the basics and more toward advanced solar topics.
RV Solar Charging Basics
A solar panel in your RV can keep your batteries charged so basic functions like your water pump, 12 volt lights and other devices continue to run. While solar charging is not the most powerful choice when compared to running a generator, it is superior because it works without requiring any fuel except sunlight. It also requires very little maintenance as long as the sun rises every day to insure charging. (By the way, if the sun doesn't rise, I think there may be bigger issues at hand than worrying about your RV battery charging. LOL!)
A solar panel is best used to charge your battery bank. The more solar panels you have, the faster your battery bank will recharge; the more batteries you have, the longer your RV can run off grid. There are also considerations for other items in a solar RV charging setup like cables, brackets, charge controllers and orientation. See the section on RV Solar Charging Equipment.
WARNING: Many new so called RV Solar Kit dealers have popped up on the internet. They are selling home panels and low-grade panels as RV grade panels. They will even claim that these panels and kits are RV grade. Be careful, trust the Go Power brand. Go Power has been an RV Solar kit standard for over ten years and many RV dealers carry this brand for this reason. Carmanah and Go Power design their RV kits to be installed safely and reliably on RV applications.
- RV Grade Solar Panel
- RV Mounting Brackets
- RV Mounting Hardware
- RV Grade Solar Wiring
- Solar Charge Controller
- Battery Bank Connection
- Battery Bank
- Silicone Sealant for Permanent Installation
Installing a solar panel system in your RV may require the following tools and skills:
- DC Electrical Wiring Experience
- RV Wiring Experience
- Knowledge of possible wiring Location
- Volt Meter
- Cordless Drill
- Various Sized Drill Bits
- Jig Saw
- Stud Finder
INSTALLING A SOLAR PANEL PERMANTLY ON YOUR RV ROOF MAY REQUIRE YOU TO DRILL HOLES INTO ROOF. IF YOU ARE NOT ABLE TO DO THIS PROPERLY, HIRE SOMEONE WHO CAN. SAVE YOURSELF UNNECESSARY OF TROUBLE AND GET IT DONE RIGHT. MANY CUSTOMERS HAVE SUCCESSFULLY COMPLETED INSTALLATIONS THEMSELVES, BUT THEY HAVE HAD VARYING SKILL LEVELS. ALWAYS BE CAREFUL WHEN INSTALLING ANYTHING ON OR NEAR YOUR RV ROOF; WATER IS YOUR ENEMY.
The next step is purchasing the proper solar panel charging setup to match your needs. There are a few factors to consider including power sizing, physical sizing, panel efficiency, and solar expansion potential.
Sizing the Wattage of your RV Solar Panels for your needs:
Sometimes the best way to size an RV solar system is to look at example systems.
RV Solar System Example 1
If you have a 100 Amp hour battery that lasts around three Days, it would be best to recharge your battery every day to keep from over draining your battery.
Determine how many watts of solar you would need to replenish this in the solar hours in 1 day.
Lets use the 95 Watt Solar panel as the basis for our calculation. Lets also use 7 hours of sun per day.
If you use 1/3 of 100 Ah per day or 33.3 Ah. You have to replenish 33.3 amps in seven hours = 33.6Ah/6h = 4.8 Amps. Following the charging amounts for the Go Power 95 watt Solar kit per day based on varying solar hours per day. As you can see one 95 watt solar kit would meet your RV power needs.
Solar Hours Amps Per Solar Panel Approximate Amp hours Added to battery 4 5.4 21.6 5 5.4 27.0 6 5.4 32.4 7 5.4 37.8 8 5.4 43.2 9 5.4 48.6
RV Solar System Example 2
If you have a 300 Amp hour battery bank that last you around 2 Day Go Power 380 Watt RV Solar Panel Kits, it would be best to recharge your battery every day to keep from over draining your battery.
Determine how many watts of solar you would need to replenish this in the solar hours in one day.
Again let's use the 95 Watt Solar panel as the basis for our calculation, and five hours of sun per day.
If you use 1/2 of 200 Ah per day or 100 Ah, You have to replenish 100 amps in five hours = 100Ah/5h = 20 Amps. Following are the charging amounts for the Go Power 95 Watt Solar kit per day based on varying solar hours per day.
You will need 20 amps of charging at 5.4 amps per panel: 20 Amps / 5.4 amps per Panel = 3.7 or 4 Panels.
As you can see 380 watts of solar will meet your RV power needs and you will want our 380 Watt RV Solar kit.
Solar Hours Amps in 380 Watt Solar Panel kit Approximate Amp hours Added to battery 4 21.6 86.4 5 21.6 108.00 6 21.6 129.6 7 21.6 151.2 8 21.6 172.8 9 21.6 194.4
Budget Versus Solar Needs:
Needing more Solar panels on your RV obviously means more Money:
The more watts of solar panels you purchase, the faster your batteries will charge and the more output in your system. However, more panels cost more money, so most people get to point where they have enough solar power to meet their needs and not break the bank. Get as much solar as you can afford that will size your system properly. Since we must all live within our means. If you need three panels, but can only afford one now, buy the one solar kit and expand it as funds become available.
Sample Budget For Number of Watts of RV Grade Solar
|5 Watt Trickle Charger||N/A|
|10 Watt Trickle Charger||N/A|
|20 Watt Solar Charger with Controller||N/A|
|40 Watt Solar Setup with Controller||N/A|
|50 Watt Solar with Controller||N/A|
|80 Watt Solar with Controller||$500 to $550|
|95 Watt Solar with Controller||$587 to $650|
|160 Watt Solar with Controller||$700 to $800|
Solar Panels Require Space:
The more solar panels you buy to add to your RV, the more space you need to install or carry them. More panels also require more wiring, larger charge controllers, and a better installation plan. In fact, many larger solar arrays for RV's are designed to be set out once the RV is parked. This allows for better orientation of the panels to the sun and also allows for shaded RV spots since the panels can be moved away from the shaded area. They do not, however, charge the batteries until they are set out, unlike permanently installed roof mount panels. Find or make an installation plan or setup that works for you. Included are a few samples but moreRV solar layout samples can be found here.
Here is a sample layout of 570 watts on a toy hauler. Plenty of space is left for growth on this 44-foot RV.
Here is a sample layout of an RV solar kit on a 20 foot RV.
Wiring and Connectors for RV Solar Kits
Wiring your RV Solar Kit is always an important consideration. I wanted to include some information on the wiring setups that come with better solar kits. Quick connect MC cable setups are a must for ease of wiring and installation.
Connecting an MC cable setup is easy on one of our RV Solar Kits.
MC3 & MC4 Solar Connector types:
The Wire from the Panel will go to the Solar Charge Controller. The Solar Charge Controller will have four connections:
- Array +
- Array -
- Battery +
- Battery -
You will need to determine the polarity of the connections coming from the junction box of the solar panel. I wanted to include an RV solar tip that helps you easily determine the polarity of connections for years to come. This video shows the Go Power RV Solar Kit with 95 Watt Solar Panel.
Expanding your RV Solar Charging System
Can your RV system grow as your needs change. One of the things to consider is how many amps can your charge controller, wire and roof handle. RV solar systems that can grow to about 350 to 400 watts are preferable and will cover many RV users needs. For much larger systems, a second solar system can be added using another base kit if more watts are required and will give you some redundancy on systems. So if you have one system failure, you still have one complete solar charging system running. It can also help with shading issues on larger coaches.
Adding additional solar panels can be as simple as making a nice, watertight install using a branch connector. Here is an informational video on using MC branch connectors to add expansion panels to a base RV solar kit.