How To Hook Up Solar Panels To RV Batteries

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You have done all of the consideration, all the research, and finally come to a decision; you are ready to hook up solar panels to your RV batteries. The hope is to save on your generator costs, and generally Go Green as you hit the road.

The process of setting up your solar panels so that they are connected to your RVs batteries may seem like a difficult battle. With a lot of electrical components and moving parts to account for, there is much you will need to keep in mind in this process. However this is something that you can do, given enough time and resources.

You will need to mount the solar panels, connect the charge controller to the battery bank, and connect the controller to the RV solar panels. Then check the connections to ensure that everything works as expected. Finally, connect the solar inverter to the battery.

How To Hook Up Solar Panels To RV Batteries

The solar panels that you will find for RVs work in much the same way that a residential solar panel does. The panels capture sunlight, and convert that light into electricity. You then use that solar electricity to power your appliances.

There are specialized portable solar panels designed for easy setup and takedown on rvs. Manufacturers have also devised small, flexible panels that are intended to be mounted on an RV’s roof.

RV solar panels can be a cost-effective, and environmentally friendly way to use electricity on the go. Once you have them all set up, the solar panel systems require little maintenance; they are dependable and convenient. They are especially beneficial for those who travel a lot, or rely on boondocking.

What You’ll Need 

The preliminary step to hooking up solar panels to an RV is to gather your materials. 

Since you are going to be installing your solar panels on your RV’s roof, take a minute to sweep off and clean the area where the panels will sit. Not only will this give you a tidy surface to work on, but it will help as a part of general RV maintenance.

You will of course need the expected materials: the solar panels themselves, a 12 volt deep cycle solar battery, a charge controller, and a solar inverter. However you will need a few other essential components. 

Gather together: 

  • A screwdriver, 
  • Copper wires with clips, 
  • Electrical tape, 
  • An MC4 connector.

For your safety, it is also recommended that you wear a pair of gloves that are thick, but that you are still able to be dexterous in. Since you are going to be working with electrical components, rubber-based gloves are best.

If you are not confident in setting up your solar panels, call a mechanic or RV repair service.

Step One – Mounting The Solar Panels 

First things first, you will need to install your solar panels onto the RV using the mounting brackets. Most solar panels that you purchase will include their own mounting brackets, allowing you to attach it to the roof.

When choosing the location for your solar panels, consider the spots where they will most likely be exposed to sunlight. It may seem obvious, but maximizing the sun exposure on your solar panels will allow you to get the most charge out of them.

Importantly, you will need to install a platform on the RVs roof for your solar panels. Aluminum rails are lightweight and durable, and will be able to withstand wind pressure from driving.

If you are using a lot of solar panels, consider a parallel wiring or series wiring setup. 

A parallel wiring setup allows the negative terminals of the solar panel to connect to the negative lead of the battery. In a series connection, the negative terminal of one panel is connected to the positive terminal of another panel. These are then joined in a combiner box.

Step Two- Connect The Controller To The Battery Bank 

After all of your solar panels are placed somewhere where they will get maximum sun exposure, and they have been connected appropriately, it is time to connect to the charge regulator.

As discussed, a charge controller is crucial to your solar system, as it Bridges the RV solar kits and the batteries. You should always connect the battery with the controller if you want to avoid a sudden surge of power that would damage the controller.

To connect the solar power battery to the controller, find the positive and negative wires from the battery terminals. Slide them into the input ports on the controller specified for a battery. Once they are in, tighten the screws to ensure that everything will be kept firmly in place.

Step Three – Connect The Controller To The Solar Panel

A special connector, called an MC4 connector, will be needed to wire your solar panels to the controller. These usually appear as a long cylindrical fitting, with a male and female end. Your solar panels should fit well with them. However, if you find that they do not fit, you’ll need to attach them manually. 

MC4 connectors are easy to find at electrical equipment stores or online. Most will have easy to follow instructions letting you know how to properly connect them.

The wire you will see attached to your RV solar panel will usually be rather short. It might not be able to reach the controller. In this case, manually measure the length of wire that you will need for the connection. As you do this, bear in mind that the controller needs to be kept near the batteries.

With the input wires in place, match up the male and female connectors and snap them into position. Listen for a ‘click’ sound; that is how you will know that the connectors are seated securely.

Step Four- Check Your Connections 

Now that you have seen to the wiring, it is time to check to see that everything is functioning as you want it to. Modern charge controllers will include a digital screen, displaying the amount of current flowing to the battery. Take a look at this reading and determine if everything is wired the way you expect it to for your voltage and battery size.

Allow the RV battery to fully charge. How long this will take depends on your solar panel wattage, how sunny it is, power usage, and battery size.

With this, your RV solar system will be up and ready to power all of your appliances on DC power. 

However, you may know that most of your appliances, especially ones that are intended for housing that you have brought into using your RV, are AC powered. This is a common issue that RV owners face, both in and outside of the realm of installing solar panels. 

The solution lies in the installation of an inverter. This is an additional step to hooking up your solar panels to RV batteries that will allow you to run on AC power.

Step Five- Connect An Inverter To The Battery 

An inverter’s job is to invert, or translate, DC power into AC. It is not to be confused with a converter, which does the opposite job of converting AC into dc.

Your trusty inverter will take the DC energy coming from the solar panels and turn it into 110 volt AC power. This will allow your RV to use it. With a solar inverter, connect the RV battery to the lugs, and thus connect those into the AC appliances. 

Once that setup is complete, you should be able to run everything on AC power. That will allow you to use items like your refrigerator, tv, and microwave.

Things To Consider Before You Begin 

The most straightforward way to hook up a solar panel to RV batteries is to connect the positive wire from the panels themselves to the battery’s positive terminal. Then, following the same principle, you connect the negative wire to the negative battery terminal. The resulting circuit will be able to charge the solar battery pack and power your appliances

The problem arises in two forms: battery discharge and battery overcharge.


Battery discharge comes about when the battery is fully charged, but no solar energy is falling on the panel. This causes electricity to slowly leak into the solar panel, which will gradually discharge the battery. While this does not account for significant amounts of leakage, it is still worth keeping an eye out for.

The solution to this battery discharge is placing a battery diode in line. The diode is a one-way valve for electric power, thus stopping the current from leaking into the solar panels.


As for battery overcharged, this issue is much more critical, and will need your attention right away. Battery overcharged can lead to damages to the battery itself, and to your RV appliances. If left unattended RV solar panels have the possibility to overcharge. That overcharge leads to the battery and damages it via overheating.

A charge controller however, will alleviate this problem as it stops solar power from getting into the battery once it is completely full. 

This unit, also called a regulator, sits between the RV solar panel and the battery pack. It’s job is to oversee the flow of charge to the battery from the solar setup. Most 100 watt solar panels rated for 12 volt batteries put out about 16 volts to 20 volts. That overcharge can damage a battery without a monitor.

A solar charge controller will regulate the panel voltage and load current using a set of operational amplifiers. Using a comparator, the controller senses the battery’s current state. LED lights will usually show that state, allowing you to check it as needed. 

In order to prevent overcharging and the resulting damages associated with it, your controller will use a metal-oxide semiconductor field electric transistor, or MOSFET.  When the transistor senses that the battery is full, all additional power that the solar panel delivers is bypassed into a dummy load.

When you are hooking up solar panels to RV batteries, it is imperative that you have a solar charge controller.

How Many Solar Panels Do You Need? 

Not all RVs are built the same. Any RV owner can easily testify to this. Therefore, it stands to reason that every RV, and every RV owner, will need a different number of solar panels.

RV solar panels typically come between 100 and 400 watts of power. An average sized RV will need three 400 or ten 200 watt solar panels in order to meet its energy demand.

Why so many? The reasoning here is that an average RV solar panel setup is sized at about 800 watts, an amount that will allow it to power most of the smaller appliances within the RV.

For example, something as simple as a light bulb will usually need about 60w of power consumption. Assuming typical hours of daylight and normal habits, it will see about six hours of daily use. Therefore the daily power consumption, or watt-hours, is 360.

If you have an 800 watt RV solar panel system, sat in direct sunlight for 5 hours a day, the math rounds out that you will produce about 4,000 watt hours of energy. That should be more than enough energy to power small devices, like your lights and TVs. However, you might fall short on bigger things like your refrigerator – something you would likely enjoy using throughout the entire day.

The fact of the matter is that your solar power system will not be able to entirely power every appliance within your vehicle. It will power most of your small electron electronics and keep the lights on. As handy and efficient as it is, it is not an unlimited power source. Especially for energy-guzzling devices, RV owners rely on a mixture of solar power and their generators to keep everything afloat.


The first step to getting your RV hooked up for solar power is to set the panels. Setting up these panels can be a slightly laborious process, but not one that requires a lot of heavy lifting. Once you mount the solar panels, connect the controller to the battery pack, and then back to the solar panel itself. 

Give everything a once over to ensure that it is working before connecting an inverter to the battery. The inverter will allow you to run your appliances on AC power, as most of them require.

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