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:
- Learn More About RV Solar Kits
- Laying Out Solar Panels On Your RV Roof
- 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
- Determining 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 Connectors for solar panels
- Proper wiring of charge controller
- Portable versus fixed solar kits
- Silicone 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. These sites are great when needed, but many of our RVers want to get away from the hustle and bustle of campgrounds.
- Generator Power -- This is a great short-term, off-grid power source. Running on a generator has several issues to consider:
- Fuel Cost - depending on your generator, fuel cost can really add up. RV generators are often powered by gasoline, diesel or propane.
- Noise - Running a generator is often accompanied by a continual engine running sound that can be annoying when trying to get some peace and quiet.
- Generator Service Schedule - Maintenance on a generator is key to continued reliable operation. Check your generator's manual to find out what your service schedule requires based on hours of run time.
- Generator Bans or Schedules - Many parks around the country have banned generators completely or limited generator use to only a few hours per day according to their approved schedule. This is due to the pollution they create. They create not only exhaust but also noise pollution.
- Battery Power -- Running on battery power is a silent way to run many of your low voltage loads like lighting, water pumps and fans while boon-docking. Running 12-volt items in your camper will drain the battery power over time. A power inverter can allow the running of 120 VAC devices in your camper. These can include items like microwaves, computers, TVs, coffee makers, blenders and video games. These 120 volt loads can definitely drain your battery bank at an increased rate. This is where a solar panel charging system can provide remote charging for your off grid RV application. Once installed, solar panels work during the day to recharge your battery. This allows for extended run times when out in the wild.
This article will focus on 12-volt solar panel charging systems for operating your RV completely off-grid. Any time we discuss solar panels for your camper, please remember that areas that have less sun will require more solar watts to achieve the same charging levels. When discussing solar panels for your RV, it is best to start with the basics and move toward more advanced solar topics. Above and throughout the article you will find more in-depth articles about specific topics related to RV Solar Systems.
RV Solar Charging Basics
A solar panel on your RV can keep your batteries charged so basic functions like your water pump, 12 volt lights and other devices continue to run even when there are no other power sources. While solar panel charging is not the most powerful choice, it is the quietest and most rewarding. When compared to running a generator, solar is superior because it works without requiring any fuel except sunlight. (In this article we will primarily discuss photo-voltaic solar panels that turn sunlight into DC electricity.) 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!)
Here are 3 tips to get the most of your solar panel system:
- Device Efficiency - It is also important to consider basic efficiency in RV solar applications. Use devices that require less power: change lights to LED or use newer flat screen TV's instead of older, less efficient tube type televisions.
- Device Run Time - Also try to reduce your overall power usage. For example a light that is turned on may use 50 watts of power where a light that is OFF doesn't use any power. The less power we use, the less power the solar panels have to produce. Be vigilant about conserving your RV's power. (See the section on RV Solar Power Efficiency Tips.)
- Solar Panel Output - Knowing how many watts your panels will produce in a given day will allow you to better understand your power budget for that time frame.
- Battery Bank Capacity - Having a good idea of how many Amp Hours you have in your battery bank will let you plan your off-grid consumption. Wait to run really large loads for when you have a full battery bank in your motorhome.
- Time Of Year - Depending on the time of the year, solar charging times can be longer or shorter. Time of the year can also impact the overall charging your panels are able to receive when mounted flat.
- Geographic Location - The further north you are and the more cloudy your location averages can impact how much sunlight your solar panels can turn into electricity. Extreme northern locations may require tilt mounts to achieve optimal solar output.
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 designed to be used in mobile and RV applications.. 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 solar kits to be installed safely and reliably on RV applications. They even design and warranty their equipment for these uses.
- RV Grade Solar Panel
- Mounting Brackets for your RV Roof
- Mounting Hardware to attach the bracket to your roof
- Solar Wiring that can be used to connect your panels to your charge controller and batteries.
- Solar Charge Controller
- Battery Bank Connection
- Battery Bank
- Fuse or Breaker
- 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
- Ability To Read And Follow Instructions
INSTALLING A SOLAR PANEL PERMANENTLY 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 of charging. Following is a chart that demonstrates the charging amounts for the Go Power 95 watt Solar kit. The per day rate is based on the varying solar hours per day that can depend on time of year, weather and the location of your camper. As you can see, in the above example one 95 watt solar panel kit would meet your RV power needs and keep your battery in tip top shape. Adding two to three times as many solar panels will allow for even faster charge times and the included charge controller in Go Power kits will prevent the overcharging of the batteries.
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 more RV solar layout samples can be found here and we offer a layout guide for placing panels on your motorhome's roof.
Here is a sample layout of 570 watts of solar installed on a toy hauler. Plenty of space is left for growth on this 44-foot RV.
Here is a sample layout of a solar kit on a 20 foot RV.
Wiring and Connectors for Solar Kits For RV Use
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 back of the single bank controller will have four connection points available to place wires:
- 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.