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How to Connect a Solar Panel to a 12 Volt Battery – Everything You Need to Know

Updated: July 21, 2023

how to connect a solar panel to a 12 volt battery

How to Connect a Solar Panel to a 12 Volt Battery – Everything You Need to Know

Connecting a solar panel to a battery is one of the most basic tasks you will need to learn how to do if you are just getting into solar power. A solar panel that is wired to a simple 12 Volt battery is one of the simplest solar power systems you can create, which is why learning how to do so is so important.

Once you understand how to do these sorts of basic tasks, you will be ready to start reaping the rewards of generating and using your own source of clean, renewable energy.

To help you get started, we will list the basic steps you can follow to connect a solar panel to a 12 Volt battery. From there, we will recommend a variety of solar panels and solar panel kits you can purchase to build your own solar power system.

Connecting a Solar Panel to a 12 Volt Battery Step by Step

Most of the basic residential solar power systems you will see use one or more 12 Volt batteries for the power bank. This is because these solar batteries are both affordable and reliable.

Assuming you are using 12 Volt batteries, you will need to determine the size of the panels you are going to connect to those batteries. We will discuss sizing solar panels after we have explained how you connect them to a battery. 

The following steps explain how you can connect a single solar panel to a single 12 Volt battery:

Step One – Mount Your Solar Panel

One of the first things you will do after you have purchased a new solar panel is mount it properly. Not only is it important to securely mount the panel so it will not fall and become damaged, you must mount it in a position where it will receive adequate sunlight.

Given that the primary purpose of a solar panel is to absorb sunlight, so it can be turned into useable electricity, it is of critical importance that you always position any solar panels in a location where they will receive a significant amount of sunlight. Ideally, you will find a location that is not shaded at any point during the day. It is also important to mount the panel on an angle where the sunlight will hit it directly, as this will improve the overall efficiency and energy potential of the solar panel.

Step Two – Position the Charge Controller and Your 12 Volt Battery

While it would be nice if you could just plug a solar panel directly into a battery, it is not that simple. You must purchase and install a solar charge controller. The function of a solar charge controller is to regulate the power flowing from your solar panel to the connected battery bank.

In simple terms, the solar charge controller will regulate the voltage and current to prevent your battery, or batteries, from overcharging. This is important because overcharging a battery can cause permanent damage and reduce the battery’s ability to hold a charge in the future.

Most 12 Volt solar panels actually put out about 16 to 20 Volts of electricity, especially during midday when they are exposed to direct sunlight. Without a solar charge controller to regulate the flow of this electricity, the batteries would quickly become damaged.

The best solar charge controllers, meaning MPPT charge controllers, also prevent battery drain, which can occur at night when the solar panels are not generating new electricity. Essentially, electricity flows backwards through the solar power system from the battery to the solar panels, which naturally drains the battery. 

Once you have an appropriate charge controller, you can simply follow the manufacturer’s instructions to connect it to your 12 Volt battery. This process is fairly straightforward, but it is also incredibly important. 

We encourage you to take a look at our Full Collection of Solar Charge Controllers to find exactly what you need to run your solar power system safely. We carry a wide variety of high-quality solar charge controllers at a range of price points. Whether you are looking for an inexpensive PWM charge controller, or a more advanced MPPT charge controller, we carry exactly what you need from some of the most reputable brands in the entire solar industry.

Step Three – Make Sure Your Solar Charge Controller is Running Properly

Once your solar charge controller is connected to your 12 Volt battery, you can turn it on and make sure it is working properly. The more advanced MPPT charge controllers will often feature display screens or LED signal lights that will give you status information and tell you how the charge controller is functioning.

If you have opted for one of the more basic PWM charge controllers, it should still feature a simple indicator light that will tell you if it is on and running.

Once you know that everything is running properly, you can turn the charge controller off and move onto the next step.

Step Four – Connect the Charge Controller to Your Mounted Solar Panel

At this stage, you can now wire the solar charge controller to the solar panel. Again, the instruction manual will explain the exact wiring process you should follow. Most solar panels will come with the cables required to connect them to a charge controller; however, if yours did not, or the included cable is not long enough, you can always buy additional lengths of solar cable for a low price.

Solar Power Inverters

At this point it is worth stating that solar panels generate Direct Current, or DC power. While you can charge a battery with DC power, most electronic devices and appliances actually require Alternating Current, or AC power. 

If you plan on running electronics that require AC power off of the electricity stored in your 12 Volt battery, you will also need to purchase and install a power inverter. Power inverters are fairly simple devices that convert DC into AC power. The best power inverters also help with efficiency by tracking the voltage of the solar array to identify the maximum power at which the modules can operate.

Some of the more advanced models can also interface directly with the power grid, which is useful if you ever plan on running a grid-tied or hybrid solar power system.

Step Five – Complete the Job

Once you have got to this point, everything should be connected together and your new solar power system should be generating and storing clean solar energy.

If this is going to be a permanent solar power system, you can begin concealing the wires and making sure everything looks neat and tidy. If this is a just a portable solar power system that you are using for camping, RVing, boating, or any other purpose, you are now finished and can step back and enjoy your handiwork.

Finding the Right Solar Panels 

If you do not already own solar panels, you are probably wondering what type of solar panels you will need. If you are just looking to charge a single 12 Volt battery, you can probably get away with a single 12 Volt solar panel.

The type you choose is really up to you, as solar panels come in variety of sizes and configurations. For example, foldable “suitcase style” solar panels are ideal for those that need a portable option. On the other hand, more rigid solar panels tend to be more durable and are better suited for permanent setups, as they can better withstand harsh weather conditions.

100 Watt Solar Panels

For those with basic solar power needs, we carry many 100 watt solar panels at an affordable price. This panel works exceptionally well in low light conditions and is ideal for any application. The durable aluminum frame and IP65 rated junction box make this the perfect affordable option for beginners that are looking for a reliable option they can use to build their solar power system.

200 Watt Solar Panels

For those with greater power needs, 200 watt solar panels are another excellent option. It includes the brackets and stand legs needed for a quick installation and the highly efficient solar cells will ensure you can charge your battery quickly.

300 and 400 Watt Solar Panels

For those running multiple 12 Volt solar batteries, 300 and 400 Watt solar panels offer higher efficiency and power ratings and might be the right options for your needs.

Solar Panel Kits

For those that are just starting out, one of the easiest ways to purchase everything you need at a more affordable price is to choose a solar panel kit. Solar panel kits come with all of the components you need to get started with solar power and since the equipment is bundled, the prices are usually much cheaper than if you purchased everything separately.

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Article by

Max Bair Marshall

Max is a co-founder of Shop Solar, a company that he established in 2018 to revolutionize the solar industry by simplifying the process and making it more simple and cost-effective. Under his strategic leadership, Shop Solar has grown into a comprehensive one-stop-shop, empowering over 40,000 customers to access top-quality solar and storage solutions, comprehensive information, intuitive tools, and professional installation services.

With a passion for innovation and sustainable energy, Max has successfully expanded the business's reach and impact, serving as a driving force in the company's growth and development. Today, as the leader of a dedicated team of 60+ professionals across North America, Max continues to set new standards of excellence in the renewable energy industry, with a mission to transform the way people access and utilize clean energy.

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