How to Connect Solar Panels to Battery

The sun is a reliable source of solar energy. With the current global warming, it makes sense to shift towards renewable sources of energy. While there are many sources of renewable energy, solar power remains the most affordable. However, we have not used the solar energy potential to its full potential.


Today, the best solar panel converts sunlight into solar energy at a rate of a mere 25%. Imagine if we could have a solar panel with conversion rates hitting 80%. The potential for a solar system is unlimited. We only need the technologies that will make the collection more effective.


However, with the wrong setup, or an improper installation, the amount of solar energy collected can be even lower than 25%. Therefore, this post detail connecting a solar panel to a battery. It assumes that you know the basic solar panel setup. Read on to learn how to connect solar panels to battery.

Overview of connecting solar panels to battery

Connecting a solar panel to a battery may seem like a trivial task – it is not only about taking some connectors and fixing them to the battery. Regardless of the size, a solar panel can produce enough power to run certain appliances, like charging a smartphone.


However, when one thinks of how to connect solar panels to the battery, various questions arise. Can I connect the battery to a solar panel directly? How do you connect a battery to a solar panel?


Yes, you can connect a solar panel to the battery directly. However, this has two dangers. First, the battery power may leak back to the solar panel at night, discharging your battery slowly. Second, the solar panel can overcharge and damage your battery. Hence, you need to know how to connect the battery and the solar panel correctly.


You also must know the basic solar panel setup if you are to do it correctly. There are tools and appliances that you need besides solar array, batteries, and connecting wires. In this post, we will give you the conventional process of connecting solar panels with a battery. Besides getting the maximum power for various uses, you also need these appliances to last longer.

Preparation To connect solar panels to battery

Before embarking on connecting the battery and the solar panels, make specific preparations. These include things like purchasing the right tools and materials. Hence, it is critical to recall the 5P’s, that proper preparation prevents poor performance.


A chance favors the prepared. For you to know how to connect solar panels to the battery, you need to come prepared. Below are the tools and materials to have before starting the exercise.

Tools and Materials To Connect solar panels to battery

While the tools used in the task remain relatively the same, the materials differ. You need to use materials based on your power requirements and the current flowing through the system.


When you go to an electrical shop, carefully choose the materials. That is where this process begins.


If a store does not have a return policy and you buy the wrong materials, you may end up incurring financial losses even before the process starts. Below are some materials that you would need for this activity.


  • A solar panel
  • A solar charge controller (Renogy wanderer 30A is a good choice)
  • Battery
  • MC4 solar adapter and solar extension cables
  • 12-gauge wire connectors
  • Inline fuse holder having a blade fuse of 20A
  • Heat shrink tubing
  • 15A MC4 inline fuse
  • 12-gauge Wire

To efficiently connect the battery and the solar panel, you need several tools. Some can be a DIY tool, or you can also buy some standard ones. However, the tools must be insulated to protect you from electrical shocks. The following tools are necessary when connecting a battery to a solar panel.


  • Wire crimper
  • Wire stripper
  • A screwdriver
  • A heat guns
  • Wire cuter
  • A tester
  • Gloves
  • Safety glasses
  • Multimeter

These are the minimum materials and tools that you must have. They will ensure a seamless operation and fasten the connections correctly.

Types of Solar Panel Connections

  1. Parallel Connection

This type of connection means that you connect the positive terminals of every solar panel. You then wire each solar panel’s negative terminals together. Then the two are connected to the inverter or the charging controller.


Solar panels connected in parallel share the same output voltage, but they provide a summed-up current. Such a configuration is reliable. When things like shading affect one solar panel, it does not affect the others. It is because the parallel wiring makes each single Solar panel independent.


However, the parallel configuration has some disadvantages too. Its low voltages mean that there is a high current, translating into more electrical losses. Therefore, the efficiency performance of your solar PV panel.


  1. Series Connection

When a solar panel’s positive terminal is wired to the other solar panel’s negative terminal, such a connection is called a series connection. In series wiring, the current remains the same in all panels, but it sums the voltages up.


Through the connection power = Voltage x Current, higher system output voltage means there is low current. The connection is vital for series-connected solar panels because it increases the values of voltages with every additional solar panel.


The series wiring translates into savings because of the low size of wires and length of the cables and the high efficiency of the solar PV panels. However, this configuration is not reliable. A single cable connects the entire system. If it fails, the whole system is affected.


  1. Series-parallel connection

We have so far seen the pros and cons of solar panels’ parallel and series connections. What can happen if we combine the two? It is vital to establish the connection per the current and voltage of the charge controller or the inverter.


The aim is to establish a series connection of solar panels and connect them parallel to other strings. Such a connection gets you the merits of parallel connection and those of series conception. (reliability, low costs, and lower power losses).

Step-by-Step Instructions on How to Connect Solar Panels to Battery


Step 1: Understanding the diagram

Ensure that you understand the setup/wiring diagram before beginning the connection. Then, internalize the connections and re-check if you have all the materials. However:


  • Do not connect the battery to the solar array directly. As we saw above, doing this can destroy the battery. Instead, connect them to a MPPT solar charge controller.
  • Fuse your system. It is considered a safe practice to place a fuse between the solar charge controller and the positive terminal of your solar battery. Next, place another fuse between the solar panel’s positive terminal and the solar charge controller.

Step 2: Making the battery cables

In this step, you can DIY some solar battery cables. However, if you have enough cash, you can buy standard ones. If you decide to make them yourself, here is how.


  • Measure two wires into your desired length and cut them. Strip the wires on both ends while keeping in mind that you also need to attach the fuse.
  • Pick the fuse and put the fuse inside. To find the right side of the fuse, use a fuse size calculator. Then, connect one of the fuse holders leads to the shorter battery cable using your selected wire connector. You can use a butt splice connector, preferably a 12-10 gauge.
  • Using a heat gun and shrink tubing, shrink wrap the wire connector.
  • Before you crimp the terminal connectors, ensure that you slide a section of heat shrink tubing on every battery cable. Crimp the terminal connectors of the battery to its cables and shrink wrap each connection.
  • To know what connector sizes to use, look at your battery’s positive and negative terminals.


Step 3: Connecting the charge controller and the battery

Ensure that you have your safety glasses and gloves on. It is a safety recommendation when working with a solar battery and other power materials. Ensure you read the instruction manual that comes with the solar charge controller. While many brands produce charge controllers, this part works with Renogy wanderer.


  • Connect the negatively charged battery cable (the one that does not have a fuse) to the “-” battery terminal on your charge controller.
  • Connect the other battery cable (positive), the one having a fuse, to the battery terminal marked “+.” Renogy recommends you connect the battery cables to the solar charge controller before you connect them to the battery.
  • Connect the battery positive and negative terminals to the battery cables, starting with the negative and then the positive.

Before connecting the positive cable, use a multimeter to check if it is life. You can also touch it to the battery’s positive terminal to see if there is a spark. The charge controller should switch, or you should see some light showing that the battery is connected correctly.


Step 4: Connecting the charge controller to the solar panel

To ease the installation, many solar panel cables have MC4 connectors pre-attached. It would help if you had MC4 adapter cables to connect a solar charge controller to a solar panel.


They are usually a solar PV wire stripped at one end and have an MC4 connector on the other end. You can also make your own by assembling a female and male MC4 connector. Depending on how far apart your charge controller and the solar panel are, you may have to buy extension cables.


  • Connect an MC4 inline fuse to the solar panel’s positive cable or a positive extension if you are using one. Then fix your MC4 adapter cable.
  • If you use one to the solar panel’s negative cable, connect a negative cable, and then fix the MC4 adapter wire. DO not allow the exposed wires to come into contact.
  • Begin with connecting the charge controller to the negative solar cable and then the positive. To show you have connected the solar panel correctly, the solar charge controller should blink or turn on. Now you have everything wired together.

Step 5: Place the solar panel under the sun

Place the solar panel under direct sunlight at the best tilt angle, depending on your location. If you have a solar panel mount, this is easy. After doing this, the charge controller should show that your battery is charging.


You can now sit back and collect the solar energy. Once the battery is fully charged, the charge controller will stop charging it. That is how to connect solar panels to the battery.


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connect solar panels to battery Frequently Asked Questions (FAQs)

How Do I Prepare For Solar Installation?

Installing a solar energy system is easy to escape the hefty electricity bills and save the environment. Whether it is to protect the environment, save cash, or a bit of both, most people are curious about solar installation.


Are you among these people and considering installing a solar power system? This section will take you through the preparations to ensure that you are comfortable installing a solar system.


While some preparations may seem time-consuming and tricky, partnering with a reputable solar installer can save you a lot of effort.


To prepare for a sola installation, begin by deciding the amount of power that needs. That amount determines how large the system will be. For example, how many batteries do you require?


Then understand the incentives and the local jurisdictional regulations. The incentives ensure you get a favorable return on investment within a short time. At this stage, also consider if your roof can handle the solar panel’s additional weight.


After making the above considerations, you can now contact a solar panel installer. After calling the professional installer, ensure that the area they will work on is easily accessible. Preparing to install solar panels can be a time-consuming and frustrating process.


However, it also can be easy. A primary determining factor is the professional solar installer that you have chosen. Partner with a full-time and reputable solar panel installer to ensure the work is easier. They can be your advisor and take care of the paperwork.


A professional solar installer should focus on assisting you to make the best decisions and objectives, not their profit margins.


How Do I Connect Solar Panels?

You can connect solar panels to increase the power output or charge the battery faster. However, there are two ways of connecting the solar panels that provide different levels of output; parallel wiring and series connection. You can also connect them in mixed mode. Below are connecting solar panels.


  • Step 1: installing the solar panels

With the help of a DIY solar kit or a professional, install the solar panels on your roof. To generate 5000W of power every day, you need to connect approximately 20 250W solar panels. Such power is enough to run a geyser, a few lights, and a refrigerator. Connecting more solar panels means increased energy efficiency in your home.


  • Step 2: installing the solar batteries 

The next step is the installation of solar batteries for the solar panels. Do this depending on whether you will replace your entire electricity source or still use grid power sometimes. Batteries are essential, as they store energy for later use.


  • Step 3: Knowing how you will connect the solar panels

The next step in connecting solar panels is connecting them to a power inverter, then to the home grid. You can also connect them better to the inverter and then to your home grid. The inverter changes the DC power from the solar panel to AC power.


  • Step 4: Convert the inverter to the battery

Note that solar energy can be unpredictable. Even when you have connected the solar panel system correctly, your battery can run dry or be below sunlight. It happens when there are consecutive cloudy days. That is why it is recommended to have a backup source of power, like a generator.


How Do I Connect Solar Panels to a Charger?

A charger or a charging controller is a vital component of any solar power system. To connect it to a solar panel, you follow the following three steps.


Step 1: Connecting the charger to the battery

Note that you begin by connecting the charge controller to the battery and connecting your solar panel. If you do this in the wrong order, you may end up damaging the charge controller.


  • Connect the charge controller’s negatively “-“charged battery terminal to the battery’s negative cable. You should connect the positive battery cable to the “+” terminal of the battery.
  • Connect your battery cables to its terminals, beginning with the negative terminal then positive. If the charge controller is connected correctly, it should generate power or blink.


Step 2: Connecting the MC4 solar adapters to the panel

After connecting the charger to the battery;

  • Connect the positive solar panel adapter and MC4 inline fuse to the solar panel’s positive cable.
  • Connect the solar cable (negative) to the adapter cable (negative). The exposed wires should not be allowed to come into contact.

Step 3: Connecting the solar panels

After connecting the chargers to the battery and the MC4 adapters to the solar panel, the next and final step is to connect your charge connectors to the solar panels;


Connect the “-” solar terminal of your charge controller with the negative solar cable and the “+” of your solar terminal to the positive solar cable. Your charge controller should show that you have connected the solar panel properly.


The only remaining thing at this point is consulting the charge controller’s manual to see if you need any programming like voltage and type of battery.


How Do I Connect Solar Panels to a Battery Bank?

A battery bank stores every watt of energy from the solar panel. Rather than being connected to a solar panel, the battery bank is connected to the charge controller. To connect a solar panel to a battery bank;


  • Step 1: Ensure the safety of the components and area you will work

Before you connect to the battery bank, remove the solar panels from the sun and disconnect them. It ensures that no electricity will move within the system. Test and examine the battery to ensure it does not have any rust or damages on the terminals.


  • Step 2: Removing the ring terminals and connecting the wires

The next step is to prepare your battery for the connection with the charge controller. You do this by removing the rings from the negative and positive terminals. Connect the corresponding negative and positive inputs of the charge controller and the battery terminals. If any part of the Wire is exposed, ensure that you cover it for safety.


  • Step 3: Screwing the battery rings back

To establish a firm connection securely and safely between the charge controller and the battery bank, screw the battery’s rings back. That way, you will have connected your solar panels with a battery bank.


How To connect solar panels to battery

As we have already seen, there are many advantages of using solar energy. However, correctly installing the setup is paramount. It ensures that your solar power system works efficiently and the components do not get damaged.


The review has gone through the tools, materials, and various connections between solar power system components.


We have also gone through the different questions that people frequently ask to clear any doubts. Invest in a solar power energy system to enjoy various benefits, including low maintenance, affordable, and eco-friendly power sources. Without an understanding of the basic solar panel setup, the whole exercise may now work correctly.


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