Back to Blog
Home > > Can I Connect Solar Panel Directly To Battery? A Guide

Can I Connect Solar Panel Directly To Battery? A Guide

Can I Connect Solar Panel Directly To Battery? Everything You Need to Know

Are you a homeowner who just installed a solar panel system and is wondering about the dos and don'ts, especially when connecting your solar panel to a battery?

We have some experience dealing with this dilemma and would like to share our answer to the question: "Can I connect a solar panel directly to a battery?" based on research and experience.

Let's get started!

What Happens if You Connect Solar Panels Directly to a Battery?

Connecting a big or small solar panel to a battery directly is a situation that only applies to extra-low voltage solar panels (those with a battery maintainer) connected to an electric battery or car battery.

It will not work for long when connected to lead acid or lithium batteries.

However, if you decide to connect solar panels directly to a car battery, you will need to be aware of the following risks:

  • When connected directly, a solar panel equal to or (much) larger in voltage than a solar battery voltage may cause the solar battery to overcharge.
  • When the battery is overcharged, it may get damaged.
  • Aside from the solar batteries, the appliances connected to the solar battery through an inverter will also be negatively affected.
  • A car battery is not designed for solar energy storage.

The mentioned circumstances can happen because rechargeable batteries store energy beyond their capacity.

To regulate the flow of solar power that solar PV panel produces, you need to mediate the panel and the battery using a solar charge regulator, which will be explained more in the following sections.

FACT: PV stands for the photovoltaic system.

Pros and Cons of Connecting Solar Panels Directly to a Battery

Like any other electrical connection, connecting a solar panel directly to a battery has its pros and cons. To help you weigh things out, we listed all of them in this section.

Solar Panel Installation – Get Your Free Quotes Today
Compare quotes from different installers to get the best pric.  We’re not here to sell you anything. We will give you unbiased advice and match you with suitable installers.

    Request Quotes

    What solar quotes do you need?

    Preferred time of installation?

    Which of these best describes your home?

    Property ownership?

    Which direction does your roof face?

    What is the pitch of your roof?

    What material is your roof?

    Is there any shading that impacts your roof?

    Are there any windows on your roof?

    We care about your privacy

    Privacy and Cookies Policy

    Thank you for using Solar Panel

    What happens now?

    • Our customers service team reviews your request.

    • We will contact you by phone to confirm your information.

    • Based on your information, we will match you with relevant suppliers who will contact you directly with their respective quotes.

    Pros of Connecting a Solar Panel Directly to a Battery

    When you connect a solar PV panel directly to a battery, you can experience some of the perks of a complete solar power system. The pros are listed below; read through! 

    Helps Store Surplus Electricity

    As with every solar system, an efficient solar battery charging stores excess electricity with or without a solar regulator.

    With this, even during nighttime, when there is no direct sunlight or during unscheduled power outages due to unlikely weather, you can still have as much energy as you need to generate power throughout your appliances.

    Reduce Your Carbon Footprint

    Since you are using renewable energy, you will be helping the environment by reducing your carbon footprint. 

    Experts from the United Nations have pointed out that using solar energy will not produce any noticeable emissions that can be considered harmful to the environment. 

    Cons of Solar Panels Connected Directly to a Battery

    Here are the disadvantages that come when a solar PV panel is directly connected to a solar battery:

    Damaged solar batteries

    It is apparent that once you connect a solar panel that is not low-voltage directly to a solar battery, it can damage the latter through overcharging, which also creates overheating.

    The main products of the direct connection of solar panels to the batteries are the following:

    • Shorter battery life cycle (which leads to it becoming impossible to use later on)
    • Lesser efficiency
    • The liquid that balances the chemical reaction inside the battery gets affected

    Damaged appliances

    Given that the flow of electricity from your solar PV panel to your battery is too much, the disproportion can also manifest in the appliances, gadgets, and electric vehicles you connect with the battery.

    It can stress the loads, which can result in the following:

    • Shut down 
    • Malfunctions

    Electrical accidents

    An electrical accident is the worst that can happen when overcharging a solar battery by directly connecting a solar PV panel system to it.

    Some of the electrical accidents you can experience are:

    • Toxic fumes
    • Exploding batteries
    • Leaking and flaming

    What Does a Solar Charge Controller Do

    A solar charge controller acts as a voltage regulator that moderates the voltage and current from the solar PV panel to the battery.

    With this function, a solar charge controller helps keep the solar battery voltage on maximum power while preventing it from overcharging and overheating.

    It also has other essential roles in the solar panel system, such as:

    • Disconnects the flow of voltage and current from solar panels to batteries once it is over the solar module
    • Contains the Blocking diode to stop power flowing in reverse

    Solar chargers also have two different algorithms that make them functional, which are:

    • Maximum power point tracking (MPPT)
    • Pulse width modulation (PWM)

    The MPPT solar charge controller allows a slight difference in the battery and panel's voltage, while a PWM solar charger requires a constant voltage.

    Why a Charge Controller is Needed to Connect Batteries to Solar Panels

    Some solar PV panel owners still wonder why they need an MPPT charge controller despite knowing what it does. 

    Here are the reasons why you must have a charge controller connected between your solar panels and batteries:

    • It protects the solar battery voltage from becoming too high, leading to overcharging and overheating.
    • It prevents the reverse current of the solar power (e.g., blocking diode).
    • It protects the internal circuitry of a solar panel system.
    • It safeguards the maximum power of solar energy to prevent burning by regulating the charge voltage.
    • It prevents the draining of the solar battery.

    How to Connect a Charge Controller to a Battery and Solar Panel

    Now that you know that a charge controller is needed to connect a solar panel to the battery, here is a full guide for embedding it into the solar power system.

    Required Tools and Materials

    First, you need all the tools and materials essential to connect solar panels directly to a charge controller and the solar battery.

    It is crucial that you have these things ready and arranged properly near your work setting as it involves the following perks:

    • Easy access 
    • Faster installation time
    • Personal safety

    Here is a list of what you will need:


    • 12-volt solar panel and solar battery
    • 12 gauge wire and wire connectors
    • 15 ampere MC4 inline fuse
    • 30A solar charge controller
    • Heat gun and shrink tubing
    • Inline fuse holder (20 amp blade fuse)
    • MC4 solar adaptor cables
    • Screwdriver, wire cutter and stripper

    Safety equipment

    • Gloves
    • Rubber-soled shoes
    • Safety glasses

    Step-by-Step Instructions

    After securing the necessary pieces of equipment, you can now follow this straightforward step-by-step guide when connecting your panel to your battery:

    Step 1: Wear Your Personal Protective Equipment

    The first thing you need to do is wear your personal protective equipment (PPE). You must not skip this step as it secures you from potential hazards that come with the job.

    As we have mentioned, the essential wearable pieces of equipment are gloves, rubber-soled shoes, and safety glasses. Here are their functions:

    • The gloves can protect you from electrical shocks
    • The rubber-soled shoes can act as an insulator to prevent electrocution
    • The safety glasses protect your eyes from electrical discharges

    Once your PPE is secured, you can proceed with the next step.

    Step 2: Connect the Battery to the Charge Controller

    The next step involves connecting the lithium or lead battery directly to the charge controller. This step is easy to perform, as all you have to do are the following:

    • Connect the battery cables to the charge controller's battery terminals
      • Connect the negative battery cable to the charge controller's negative battery terminal
      • Connect the positive battery cable to the charge controller's positive battery terminal
    • Programme the battery charge controller according to the type (e.g., lead acid battery, lithium battery), size of the solar battery, and battery capacity 

    You can also check the manual of your lead-acid battery (or other battery types) for more specific instructions unique to the brand and type of lead-acid batteries you're using.

    Step 3: Connect the Solar Panel to the Charge Controller

    After connecting the lead-acid battery (or lithium) to the battery charge controller, you must connect the solar panels directly to the charge controller.

    It is easy to make this connection if you follow these specific steps:

    • Connect the MC4 solar panel adaptor cable to the solar panel's negative cable
    • Connect the 15 amp MC4 inline fuse and MC4 solar adaptor cables with the solar panel's positive cable
    • Connect the negative solar panel cable to the negative side of the charge controller
    • Connect the positive solar panel cable to the positive side of the charge controller

    Again, you can countercheck this step with the manual that comes with your lead acid batteries (or other types) to tailor-fit the process to your particular panel.

    Step 4: Check and Finalise

    Once you finish steps one through three, you must take the final critical step, which involves checking and finalising. 

    This step entails ensuring that every connection is up and running. You will need to:

    • Put the solar panel under direct sunlight
    • Make sure the solar panels are on the right angle and position
    • Make sure that the charge controllers indeed charge batteries (i.e., flashing lights are visible)

    Tips and Warnings

    In our experience, faster installation and efficient use of charge controllers are achievable with the steps above and the tips and warnings listed below. Read on!

    • Follow your local codes and regulations on producing electricity, including those on solar panel installation and any licences you may need to secure;
    • Turn off the circuits before working on the electricity that connects solar panels directly to charge controllers and batteries;
    • Do not work near flammables;
    • Ensure all electric wiring and connections are tight and secured; and
    • Always wear your PPE.

    Safety Considerations When Connecting Solar Panels Directly to a Battery

    Safety considerations must always be observed and acted on in every installation process that includes electrical wiring.

    To provide you with enough knowledge, here are the safety precautions you must take when you connect a solar panel to a solar battery.

    Ensuring the Right Solar Panel Voltage

    Always remember that the solar panel voltage is preferably two voltages higher than the lead acid batteries, lithium-ion batteries, or other recharging batteries.

    With this, you can ensure the battery charging is within normal limits. It also results in the prevention of overheating and overcharging of lithium batteries or deep cycle batteries (i.e., lead batteries).

    Ensuring the Right Solar Panel Wattage

    Also, make sure to learn the wattage of your solar panels because it explains how well your panel generates solar power.

    Similar to what we mentioned with the voltage, having a larger watt solar panel compared to the wattage of your solar battery may waste or give off too much energy.

    Moreover, when the watt (solar panel) is lower than that of the battery, then it may result in a more extended time when charging batteries.

    Either way, the solar panel will be inefficient for providing electricity to your solar-powered home.

    Ensuring the Right Solar Panel Amperage

    Aside from the voltage and wattage of solar panels, it would help if you also considered the solar panels' amperage.

    For the same reason, a solar panel amperage that suits the solar battery and your electric consumption needs can work better and is more energy-efficient.

    Other Important Safety Considerations

    Here are other important safety considerations you must be wary of when connecting a solar PV panel with solar charge controllers and batteries.

    Observe the Correct Polarity

    Observing the correct polarity when connecting solar panels directly to the charge controller and the batteries is essential.

    The positive (female) connector must be connected to its positive solar panel counterpart, and the same goes for the negative (male) connector.

    If you do it incorrectly or through reverse polarity, it can cause you to experience the following disadvantages:

    • Limited or no solar energy generation
    • Damaged solar panel kit, solar charge controller, batteries, solar inverter, and other appliances
    • It may burn your equipment or start a house fire

    To ensure the correct polarity between the solar panel, solar controller, and battery, you can observe what the volt meter shows. If it is a negative number, it means it possesses an incorrect polarity.

    Appropriate Work Environment

    Observe the following practices in your work environment:

    • Do not work alone. Having someone who watches or assists you while installing your devices is always better.
    • Do not work outdoors, especially when the weather is unfavourable for the solar panel, battery bank, and electric wirings.
    • Make sure that you work in a well-ventilated space.

    Other tips

    You can also bank on the following safety considerations for a smooth-sailing solar panel, controller, and battery installation:

    • Do not cut any wirings from the solar panel kit if not needed or instructed.
    • Do not step on solar panels directly when you are connecting wires
    • Do not touch any parts of your solar kit when it is wet

    Frequently Asked Questions (FAQs)

    You may have questions in mind that you want answered. We have addressed some of your solar panel and battery-related FAQs in this section.

    How Long Does It Take to Charge a Solar Battery With a Solar Panel?

    The solar panel produces electricity that can fill a solar battery in five to eight hours, depending on whether the battery charging is fully drained.

    Can I Use a Solar Panel Without an Inverter?

    Yes, you can use a solar panel without having an inverter for your solar system.

    Yet, it will depend on what type of current your appliances need. Inverters are unnecessary if your appliances mainly use direct current (i.e., DC electricity or DC power).

    What Are the Types of Batteries I Can Use for My Solar Panel?

    There are four types of batteries that you can use for storage of your excess solar energy, and these are:

    • Lithium battery
    • Lead battery
    • Nickel-cadmium battery
    • Flow battery

    Of these four, solar PV installers and owners usually use and prefer lead and lithium batteries, as they are efficient and cheap in terms of solar battery price.


    A solar system connecting solar panels directly to the battery is possible, especially when connecting it with a car battery or RV.

    However, this connection with car batteries or RV batteries can lead to adverse effects, such as damaged solar PV batteries, appliances and electrical accidents due to overheating and overcharging.With this, connecting a solar charger controller between the panel and the battery is much safer and allows you to regulate energy flow and the blocking diode. This can be accomplished by following the steps above.

    hello world!
    Share this
    Mark McShane
    Content Writer
    Mark McShane is a seasoned professional in the solar industry and the owner of Skills Training Group, a leading provider of solar training and education. With years of experience in the field, Mark has developed a deep understanding of the latest trends, technologies and best practices in the industry. His expertise and passion for solar energy have helped countless professionals develop the skills and knowledge needed to succeed in the fast-growing field of solar energy. Whether you’re an aspiring solar professional or an experienced industry veteran, Mark is an excellent resource for anyone looking to enhance their skills and knowledge of the solar industry.
    Related Articles
    Solar Panel Battery Charger [Types, Specifications, & FAQs]
    Solar Panel Battery Charger: A Complete User Guide Having a solar panel installation at home already helps mitigate the negative impacts of climate change. How much more if you go the extra mile? Fortunately, the best solar chargers can be portable and used anywhere and anytime. If you have any questions about a solar battery […]
    Mark McShane
    Content Writer
    May 04, 2023
    Solar Panel Battery Price: Considerations and Factors
    Solar Panel Battery Price: Everything You Need to Consider Some of the established benefits of installing solar panels in your home are lower energy bills, a reduced carbon footprint, and cheaper maintenance costs. But, acquiring these benefits requires more than choosing the best solar panels, as it also involves shouldering the additional cost of buying […]
    Mark McShane
    Content Writer
    May 04, 2023
    Solar Panel and Battery Installation: A Complete Guide
    Solar Panel and Battery Installation: Everything You Need To Achieve Success A solar panel and battery storage duo is a good combination that can provide renewable energy throughout the night, during power cuts, or even on cloudy days. However, this duo can only be efficient and sufficient for meeting your electricity needs once correctly installed. […]
    Mark McShane
    Content Writer
    May 04, 2023
    Popular Articles
    © Solar Panel Installation Limited - SC751192 - 2024 All rights reserved. 94 Hope Street, Glasgow, G2 6PH