RV Solar Guide
Many times when we head off into the wilderness with our RV, we would like to have more power to extend our stay. There are several choices available to RV'ers.
These power choices include the following power options:
- Site Based Power (Grid Power) - Usually only found in improved parks and sites. Cost between $12 and $300.00 per night for sites.
- Generator Power - This is a great short term off grid power source. Running on generator has a few issues to consider:
- Fuel Cost
- Noise
- 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, know that areas that have less sun will require more solar to achieve same charging levels.When discussing solar panels for your RV it is best to start with the basics and work 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 in the fact that it works without requiring any fuel except sunlight. It also requires very little maintenance except that the sun is required to rise 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!)
It is also important to consider basic efficiency in rv solar applications. Use devices that use less power. Change lights to LED or use newer flat screen TV's over older less efficient tube type televisions. Also try to use less power overall. For example A light that is on may use 50 Watts of Power where a light that is OFF doesn't use any power. The less we use, the less we have to use solar panels to produce. So be vigilant about conserving your RV's power. See the section on RV Solar power Efficiency Tips.
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 is 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.
A solar panel system for your RV will usually require the following elements:
- 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 Location of RV
- Volt Meter
- Cordless Drill
- Various Sized Drill Bits
- Jig Saw
- Stud Finder
- Hammer
- Level
- Ladder
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 A BUNCH OF TROUBLE AND GET IT DONE RIGHT. MANY CUSTOMERS HAVE SUCESSFULLY COMPLETED INSTALLTIONS 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 last you around 3 Days. it would be best to recharge your battery every day to keep from over draining your battery.
So you would need to figure 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.
So we use 1/3 of 100 Ah per day or 33.3 Ah. We have to replenish 33.3 amps in 7 hours = 33.6Ah/6h = 4.8 Amps. Here is 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
|
|
|
7
|
5.4
|
37.8
|
|
8
|
5.4
|
43.2
|
|
9
|
5.4
|
|
RV Solar System Example 2
If you have a 300 Amp hour battery bank that last you around 2 Days. It would be best to recharge your battery every day to keep from over draining your battery.
So you would need to figure how many watts of solar you would need to replenish this in the solar hours in 1 day.
Again lets use the 95 Watt Solar panel as the basis for our calculation. Lets also use 5 hours of sun per day.
So we use 1/2 of 200 Ah per day or 100 Ah. We have to replenish 100 amps in 5 hours = 100Ah/5h = 20 Amps. Here is the charging amounts for the Go Power 95 Watt Solar kit per day based on varying solar hours per day.
So we 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 would meet your RV power needs. You would 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
|
|
|
7
|
21.6
|
151.2
|
|
8
|
21.6
|
172.8
|
|
9
|
21.6
|
|
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 and that will also size your system properly. Since we must all live within our means. So if you need 3 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
|
$100 to $150
|
| 10 Watt Trickle Charger
|
$175 to $225
|
| 20 Watt Solar Charger with Controller
|
$250 - $350
|
| 40 Watt Solar Setup with Controller
|
$350 to $500
|
| 50 Watt Solar with Controller
|
$515 to $700
|
| 80 Watt Solar with Controller
|
$710 to $900
|
| 95 Watt Solar with Controller
|
$895 to $1300
|
| 110 Watt Solar with Controller
|
$1050 to $1500
|
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 also 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. So find or make an installation plan or setup that works for you. I have included a few samples but more rv solar layout samples can be found here.
Here is a sample layout of an RV solar kit on a 20 foot RV.
Here is another sample layout of 570 watts on a toy hauler. Plenty of space left for growth on this 44 foot RV.
Wiring 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.
Here is how easy connecting an MC cable setup is on one of our RV solar Kits.
The Wire from the Panel will goto the solar charge controller. The solar Charge Controller will have 4 connections.
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 polarity of connections for years to come. This video shows the Go Power RV Solar Kit with 95 Watt solar Panel.
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. I like RV solar systems that can grow to about 350 to 400 watts. This 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. This will give you some redudancy on systems. So if you have one system failure you still have one complete solar charging system running. It can also help with shading issue on larger coaches.
Adding panels can be as simple as a nice watertight install and using a branch connector. Here is an informational video on using these MC branch connectors to add expansion panels to a base RV solar kit.