Solar Panels

Getting ready for spring and summer camping and RV adventures? You can save money this year, by installing a solar panel kit on your RV or motor home. Whether you’re into weekend camping or want the total off the grid boondocking experience, DC Direct Connect offers these helpful hints for solar panel installation.

Choose a sunny spot for installing your solar panel kit.

Avoid shade on your entire panel for optimal panel output.  Position your panels out of the shade cast by other items on your RV’s roof. Additionally, try to park your rig in spots that get the most sun exposure. However, solar panels work better at moderate or cool temps, so parking in the boiling sun, anywhere in the southeast can affect your solar panels’ efficiency.

How many solar panels will you need to mount on your roof?  

That depends on how much real estate you are working with and the size and amount of solar panels you need to live a reasonably civilized life. Determine how many amps of power you use on any given day. Search “Energy Use Calculators” and choose one to calculate your average energy use. Deciding how many amps you need to power your lifestyle will determine how many panels you need to install.

What do you need to power on an average day?

Most people will need to use some sort of lighting at night. If you camp during the colder months or in cooler climates, you probably want to use a furnace overnight. Some RV and motor homes are setup with propane heating and cooking systems to save energy. You might want to use a fan and probably a TV and a satellite receiver, a radio, laptops and cell phones, GPS and a charger for your battery-powered tools.

Keeping in mind that you will only use many of these items for a short amount of time and some not every day, a few panels can handle these types of items. Remember to take into consideration some things that run all of the time, like your propane leak detector, your battery charge controller and some things like your water pump that comes on whenever you use your water.

Unless you have a RV or motor home with banks of batteries and panels installed on it, running an air-conditioner can be problematic. That’s when you might have to break out your generator. So, for average weekend type solar power, 270 watts or two 135-watt panels should do the trick.

Batteries, Inverters and Controllers

Batteries—Your RV probably came with at least one, possibly two 12v deep cycle batteries and probably not the best batteries on the market. Since your batteries store the energy you need to run everything in your RV or motor home, it makes sense to buy the best you can afford.

If you have the option, AGM (Absorbed Glass Mat) are becoming the standard for mobile recreation applications over flooded or wet batteries because they allow for faster acid migration, plus they deliver and absorb higher amperage. However, many RV-ers use high quality 6v golf cart batteries in multiples of 2, 4, 6 and so on to achieve 12v.

Inverters—In order to convert 12v DC from your batteries to 120v AC to power your devices and appliances, you need an inverter. Of the two main types of inverters on the market, pure sine wave and modified sine wave, pure sine wave inverters produce a higher quality of electricity than modified sine wave inverters.

Charge controllers‑— To regulate the voltage and current from your solar panels going to your batteries, a charge controller is needed so your batteries don’t get damaged from overcharging.

Many options in controllers include 2 stage, 3 stage, PWM and MPPT. Going with a 3 stage MMPT controller ensures better control than PWM types do, but if you go wit a PWM controller, go with a 2 stage instead of a 3 stage cycling.

Whether you decide on a PWM or MTTP controller, the important thing is to make sure the charge controller’s amp rating is high enough for your solar panels. To find out how many amps your panels produce, check the label on your panel’s spec sheet. Add 25% of that number to get a final number. This allows room for excessive power generation.

Also, since voltage loss can be a problem and is critical going from your charge controller to your battery, using the proper cable size wire, install the controller as close as possible to the battery. But don’t go with wire that is too large, it’s just a waste of money.

Remote Temperature SensorsBecause a temperature sensor on a controller, located in a heated area cannot read the battery temperature, it can’t function properly. A remote temperature sensor will be able to alert the conroller to send more voltage when batteries are cold so they still get fully charged and will reduce the voltage in hot batteries so they don’t overcharge.

Installation—Solar panel installation is a fairly straightforward procedure, but can become frustrating if you don’t plan ahead. Make sure you have on hand or acquire all of the necessary components, shunts, mounts, connectors and hardware before you start your installation, in order to avoid making several trips to a hardware or home improvement store during the installation process. 

  • Install panels flat on roof. Tilted solar panels mounted on your roof create clearance issues and are prone to damage from wind shear and airborne objects. 
  • Because you don’t need to worry about your solar panels, use quality, heavy-duty hardware to secure your panels to the roof of your RV or motor home.
  • Read all wiring and installation manuals before you connect the battery, the controller, the inverter and any digital displays. Ignorance isn’t usually an excuse with electrical component warranties. Run all wires where they need to be connected, then think through your plan, ensuring that all displays are visible and not a distraction for sleeping, and that components that don’t need to be accessed on a regular basis, like your inverter are out of the way and all switches are reachable.

Contact DC Direct Connect with questions about installing RV solar kits and/or to purchase solar RV kit products as well as other other equipment for your happy RV and motor home.