How to Replace Solar Light Batteries – Revive Solar Lights

Are your outdoor solar lights not as bright as they used to be? Are they discharging quickly? If yes, then you might want to know how to replace solar light batteries.

Solar lights are a cost-effective and hassle-free solution for your outdoor lighting. You don’t need to connect them to a socket instead they work on solar energy.

Solar lights consist of four components. The photovoltaic cell, rechargeable battery, led bulb, and charge controller. To work properly all these components, need to be in working condition.

If your solar light is not working, then there is a defective component that needs to be fixed. You need to check all components to find the problem.

If your light is dimmer, then most probably batteries are the culprit.

Why do Solar Lights Need Batteries?

Solar lights work on solar energy. You can use that energy directly to run the solar lights. But the problem is that we need solar lights at night time when there is no sunlight.

So solar lights store energy during the day time in their batteries which are then used at night to power the solar light.

Can You Change the Batteries in Solar Lights?

Yes, you can easily replace the batteries in your solar lights. Batteries in solar light typically last for 2 to 3 years. If the battery is dead, you don’t need to buy a new light.

Instead, you can replace your old batteries with new ones and your solar light will illuminate like new.

Common Signs that Indicate to Replace Your Solar Light Batteries

Solar Light is Dimmer than Usual

If you notice that your solar lights are getting dimmer and they are not as bright as usual. This could be the sign to replace your solar light batteries.

Solar lights can get dimmer due to a couple of reasons. This could happen if their globe is not clean or they are not getting enough sunlight or their batteries are dead.

Clean your solar lights. Check if they are getting enough sunlight, and change their position. If they are still dim, then you need to change the batteries.

Batteries are Discharging Very Fast

If your solar light is not lasting enough after sunset and its batteries are discharging very fast. Then this could be the moment to change your solar light batteries.

Before replacing the old batteries charge them and install them in your other solar light and see if they are working fine. If not, then replace your light batteries.

Different Types of Batteries

There are many types of batteries available in the market. As time is passing technology is improving so are rechargeable batteries and their abilities. Rechargeable batteries are getting cheaper and better.

There are mainly three types of batteries used in solar lights.

Nickel Cadmium (NiCad)

Nickel-cadmium batteries use metallic cadmium and nickel oxide hydroxide as electrodes. They contain harmful material and need proper disposal when replaced. If not disposed of properly they can affect the environment badly.

That’s why they are been replaced by nickel metal hydrides NiMH which are an eco-friendly option. You are probably going to find nickel metal hydride batteries in your solar lights.

Nickel Metal Hydride (NiMH)

Nickel metal hydride batteries are the safest and eco-friendly option. They are the most commonly used batteries in solar lights. NiMH batteries hold a much higher electric charge than alkaline batteries.

We should choose nickel metal hydride and avoid cadmium batteries to preserve nature.

Lithium-ion or Li-ion Batteries

Lithium-ion batteries are more expensive than other batteries. They are better than nickel-based batteries and can hold more charge.

They charge faster, have low maintenance, have a low self-discharge rate, and last longer than nickel batteries. Lithium batteries are commonly found in our laptops and smartphones.

Steps to Replace Solar Light Batteries

orange colored battery placed on the table.

1. Safety Precautions

Turn off your solar light before replacing your batteries if it has the option. Always take necessary safety precautions. See the user manual of your garden solar light to disassemble it safely.

Wear hand gloves before replacing the batteries. They will protect your hands in case your old batteries are leaking.

2. Disassembling the Solar Light

Disassemble the solar light and locate the battery housing. In most outdoor solar lights, it is placed at the upper part of the light, just below the solar panel. You can refer to the user manual to locate the batteries.

3. Identifying the Type of Solar Light Battery

After opening the battery housing identify the type of batteries used in your solar light. You can verify by seeing the old batteries in your light. See their capacity and battery size. Also, check the battery type in your light.

Your solar light might be using Nickel Metal Hydride NiMH or Nickel Cadmium NiCad batteries.

Don’t mix different types of batteries in your solar light. For example, if your solar light has 2 Nickel-cadmium batteries and only one needs replacement then use nickel cadmium, don’t buy nickel metal hydride. If you want to use nickel hydride then replace both batteries. Don’t mix them.

4. Removing the Old Batteries

Now safely remove the old batteries from your solar light and keep them in a plastic bag to dispose of. I will talk about that later in the article.

5. Cleaning the Solar Light

As you have already disassembled the solar light it’s the right time to clean it. Check for the corrosion in battery housing (which is like white sand) and clean it properly.

Clean the internal and external parts of your solar light. You can check this article that I wrote on cleaning solar lights.

6. Installing the New Batteries

Insert the new batteries in your solar light. Make sure you place them in the right direction.

7. Reassembling the Solar Light

After installing new batteries reassemble the solar light. Make sure to fix everything at its right position.

8. Testing the Solar Light

Test the solar light after replacing its batteries. New batteries are usually pre charged so your solar light should work. If it doesn’t work, then your battery might be flat.

Keep your solar light under direct sunlight for a few hours to charge its batteries. After charging it should work fine.

Tips for Maintaining Solar Lights Batteries

You can increase the lifespan of your solar light batteries by maintaining them. Check the batteries for any damage. Check for corrosion and clean it to avoid further damage.

Remove the batteries of your solar lights to protect them from corrosion If you don’t want to use them for a long time.

Disposing of Old Batteries

After replacing the old batteries don’t throw them in the dustbin. Specially nickel-cadmium batteries. This could lead to a landfill site and harmful cadmium can leak into the environment and cause pollution.

Take the batteries to the nearest recycling center. You can also take them to the local electronic and hardware store which has recycling points. Dispose of the old batteries to save the environment.


Solar lights are a great cost-effective solution for your garden, pathway, or backyard lighting. But sometimes they need to have their batteries replaced.

If your solar lights are dimmer than usual or discharging very quickly, then it may be time to change the batteries.

Frequently Asked Questions – (FAQs)

Why do my solar light batteries wear out?

Solar light panel converts solar energy to electric power and stores it in a battery. As time passes the batteries start wearing out. This could be the reason your garden solar lights are not working.

How long will batteries last in my solar lights?

Generally, the batteries in outdoor solar lights may last for 2 to 3 years. After that, you need to replace them.

Why my solar battery is draining fast?

If your battery is discharging too fast, it may be a sign that your battery is weak or its life has ended.

How long it will take to charge solar light?

Solar lights can take 4 to 8 hours to be fully charged. This depends on the exposure to sunlight and the type of outdoor solar light. If solar light gets full exposure to the sun it will charge relatively fast.

Can I replace my solar light batteries with a different mah rating?

Yes, you can replace your solar light batteries with a different mah but the other specs should be the same.

You should not replace your outdoor solar light batteries with much higher mah. Because the manufacturer installs the original batteries by testing their timing and it’s enough for a full night.

Should I put regular AA batteries in solar lights?

No, for solar light regular alkaline-based batteries are not a good option because they are built for one-time use only.

What are the components of solar lights?

Solar lights consist of four components battery, photovoltaic cell, led bulb, and charge controller.

Can I replace NiCad batteries with NiMH?

Yes, you can replace NiCad batteries with NiMH but other specifications should be the same and your solar light will work fine.

Can I mix NiCad and NiMH batteries in the same solar light?

No, you should not mix NiCad and NiMH batteries in the same solar light. If you want to switch to the other type, then replace all batteries in a solar light.

Hyder Ali is a writer from Pakistan who writes well researched articles on different topics. He has been writing on Medium and other platforms for a long time. He tries his best to write correct information and help his readers solve their problems.

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