Can You Charge a Lithium Battery with a Solar Panel?

Lithium batteries have become increasingly common in recent times. Apart from the efficiencies of these batteries, they also have a low discharge rate when not in use. While these batteries are reliable, one big question many users have about them is – can you charge a lithium battery with a solar panel?

Solar panels are appropriate for charging lithium batteries. Solar panels are electrical devices that produce, store, and transfer electrical energy. Your weak lithium batteries can get powered up again with this electrical energy.

Can you Charge a Lithium Battery with a Solar Panel?

Charging a Lithium battery can be a great task, particularly if you do not know how to do it. You won’t also be able to charge a lithium battery fully if you do not know the right device for the job. Lithium batteries are extremely powerful devices with high energy density. This high density enables them to supply other equipment with sufficient energy when needed. Since they are powerful, only a more powerful device is suitable for charging them.

Can you Charge a Lithium Battery with a Solar Panel

You can count on solar panels to charge your lithium batteries. The only problem here is that you won’t be able to charge the lithium battery fully without an MPPT solar charge controller. Many electrical currents will go into the battery when you use an MPPT solar charge controller. This will make your lithium batteries charge within a short time.

More often, charging a Lithium Battery with a solar panel involves several step-by-step approaches. These steps are suitable for all types of lithium batteries, including:

Steps To Charge A Lithium Battery With A Solar Panel

Can You Charge a Lithium Battery with a Solar Panel? These are the simple steps you can follow to charge a lithium battery with a solar panel. They are general ideas, simplified, and designed to work with any lithium battery. However, it is essential that you check the instructions attached to your solar panel. This is because solar panel kits are different from one another. Also, they usually have different charging procedures.

Steps to Charge a Lithium Battery with a Solar Panel

Having said that, below are the steps;

1. Get a solar controller

This is where you begin. As you may or may not know, it will be quite difficult for you to charge a lithium battery using a solar panel without a solar charge controller. In general, there are two kinds of solar charge controllers you can choose from. These are; PWM and MPPT controllers.

If you want to generate a good amount of electrical power to charge your lithium batteries, your MPPT solar charge controller is the best option. This solar charge controller is highly capable, efficient, and powerful. It can activate more than one solar systems, at the same time.

The PWM solar charge controller however, is not bad. There are some disadvantages attached to using a PWM solar controller. It lacks the capacity to charge batteries until the solar panel’s voltage has reduced to a very low point. It prevents the solar array from using its complete energy, thereby wasting both current and finance.

This is not the same with an MPPT solar charge controller. It increases the current the moment there’s a reduction in the solar array voltage. It naturally regulates the current to ensure sufficient energy goes into the batteries. There are so many differences between PWN and MPPT solar charge controllers. Nonetheless, it is evident that MPPT solar charge controllers are more effective. They charge lithium batteries faster than PWM solar charge controllers.

2. Install the Solar Charge Controller

Having chosen the best solar charge controller to work with, it’s time for installation. The best place to carry out this installation is a waterproof area. Before you configure the cables, check the distance between the solar panels, battery, and charge controller. Ensure it does not exceed the length of the cables.

Also, ensure you fix other electrical components that you will be using with the solar panels. Concerning the solar charge controller, you can fix it anywhere except on a metal surface.

3. Configure the Cables

Before you configure the cables that came with the lithium batteries, get rid of the packaging. this packaging usually come with the batteries. You can skip this step if the batteries came with plugged-in wires. If the wires are still there without proper connection, connect them to the right slots. You do not need the help of an expert to do this. You can easily identify negative wires from positive ones because they are color-coded.

Ensure the wires are in the appropriate slots, if not, the batteries will not charge. Also, ensure you secure the cables.

4. Connect the battery wires to the solar charge controller

It is ideal to mention that you have gotten everything right at this stage. Start by inserting the two loose ends of the lithium battery wires into the solar charge controller (MPPT). The ports on the charge controller should help you while you do this. They are either negative or positive. So, connect the wires to the right place.

Designs differ from one manufacturer to another. Hence, you need to watch the controller closely and do the connection the right way. Once you have inserted the wires appropriately, use a screwdriver to secure them.

5. Place MC4 Connectors on the Solar Controller Cables

At this stage, place MC4 connectors on the solar controller’s wires’ ends. You should do this while holding down the solar controller wires. Some solar panel kits do not have MC4 connectors. If yours belong to this category, you can go to any solar panel supply store to get yourself one.

6. Plug the solar charge controller wires into the solar panels

Having connected the MC4 connectors to the controller wires, go ahead to plug these wires into the solar panel connectors. You should have come across solar panels with MC4 connectors, or you should be using one. If you are using one, bridging the gap will be easy and timely.

Match the solar panel’s male and female MC4 connectors to their solar charge controller counterparts. This means that you should match a male solar panel MC4 connector to a female solar controller MC4 connector. The pattern should be the same as the other solar panel and solar controller MC4 connectors.

7. Run a test on the solar controller

Run a quick check on the charge controller cables to determine their fitness. If the solar controller fails to come on automatically, turn it on. To know if your installation is successful, check if there is an error message. If there is none, then it’s successful.

8. Let the Battery Charge

Having done all of the above, it all ends here. Now you have to sit back and allow the battery to charge. Whether you are using an open solar panel or solar panels for shaded areas, do not interrupt the charging process.

You can charge a lithium battery with a solar panel if you follow the detailed steps in this guide. You don’t have to skip any of these steps unless the manufacturers or dealers have done those steps themselves. You will find yourself spending little or no time when charging your lithium batteries with solar panels. That is only possible when you follow these steps correctly.

How Long Does It Take To Charge A Lithium Battery With A Solar Panel?

The answer to this question is inconclusive. This is because the number of hours it will take a lithium battery to fully charge when using a solar panel depend on the following factors;

How long does it take to charge a lithium battery with a solar panel

  • How many hours of sunlight is available per day.
  • Size of the solar array.
  • How much power remains in the battery.

For instance, a solar panel with an electrical capacity of 300 watts can charge a lithium battery of 100ah within 4 to 5 hours. The possibility of this also depends on atmospheric conditions and the availability of the sun. Cloudy, rainy, and shady skies can determine the rate at which a battery charges.

Let’s take a mathematical approach to help you understand this subject very well. Within a period of 4 hours, a 300 watts solar panel should charge a lithium battery of 12V 100ah. Below is the calculation.

12V × 100ah = 1200 watts


300 watts × 4 hours of sunlight = 1200 watts.

This simple arithmetic proves that 4 hours should be enough to charge a lithium battery of 100ah. However, this calculation depends on the ability of the solar panel to produce 1200 watts within 4 hours. The atmospheric condition is another thing to take into consideration. It might take up to 5 hours to charge a lithium battery during less favorable weather. If you intend to charge a lithium battery faster, you can use a big solar array. It’s a better option.

Do You Need A Special Charger For Lithium Batteries?

The PWM and MPPT solar charge controllers are other alternatives you can use to charge your lithium batteries. As explained in previous paragraphs, an MPPT solar charge controller gives better result.

Although MPPT solar charge controllers are more expensive, they can guarantee you a lot of electrical current from the array. Whenever it has to do with solar panels, all the concern is getting enough usage from inverters, batteries, and panels.

Can You Charge a Lithium Battery with a Solar Panel? Lithium batteries are quite big. This is one of the reasons an MPPT solar controller is perfect for them. On the other hand, the PWM charge controllers are more suitable for small batteries. There is a high amount of energy waste when using a PWM solar controller to charge a lithium battery. Hence, if you need a special charger to charge your lithium batteries, MPPT solar controllers can give you what you want.


Can you charge a lithium battery with a solar panel? Solar panel is a suitable device for charging lithium batteries. With quality sunlight and the right solar charge controller, you can generate sufficient energy to charge a lithium battery.

David Binion

Hi, I am David Binion, I am a technical assistant of a solar panel manufacturing company. I also have a solar panel selling and service providing shops beside my job. Because of my job & business, I have to face so many clients of the power tool users.

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