Solar Lights are a great way to keep the outdoors lit without racking up your energy bill. But there are still ongoing maintenance costs, like swapping out the rechargeable battery. Luckily, learning how to replace batteries in outdoor solar lights isn’t a tall order.
Though the details vary depending on the type of solar light, the process remains the same. The should be a removeable battery cover on the backside of the solar light. You can often remove it by sliding it off. You may need a Phillips head screwdriver to remove one to two screws first. After you remove the cover, remove the old batteries and replace them with the new batteries.
This process looks a bit different from solar garden lights compared to solar spotlights for your trees. We put together a comprehensive guide to walk you through these nuances and show you exactly how to to replace batteries in solar lights.
How To Replace Rechargeable Batteries In Solar Lights
There are several different types of outdoor solar lights. So we should first identify the type of solar light you have. For example, you could have string lights, solar path lights, or solar flood lights. Then we can go into how to replace the rechargeable batteries in solar lights of that type.
Step One – Identify The Type Of Solar Light
Use the table below to help figure out which category of outdoor solar light you have.
| Solar Light Category | Solar Light Type |
|---|---|
| Solar garden light | > Solar deck lights > Solar post lights > Solar fence lights > Solar candles > Solar pond lights > Solar walkway lights > Solar step lights > Solar path lights |
| Solar flood light | > Solar wall lights > Solar tree lights > Solar house lights > Solar spot lights > Solar garage lights > Solar emergency lights |
| Solar string light | > Solar Christmas lights > Solar string lights > Solar bush lights > Solar fairy lights > Solar umbrella lights |
| Portable solar light | > Solar lanterns > Solar flashlights > Solar hanging tree lights > Solar candles > Solar bug zappers |
| Solar street light | > Solar parking lot lights > Solar street lights > Solar traffic lights > Solar signage lights > Solar lamp post lights |
After you have found your solar light and its respective solar light category, move on to step two.
Step Two – Locate The Solar Rechargeable Batteries
Solar garden lights have the largest variety, but will often use two to four rechargeable AA batteries. Those can be found in a battery compartment on the other side of the solar panel or the light. Most can be removed by popping it off with a flathead screwdriver.
Solar flood lights fall into two categories: attached to a wall or staked into the ground. The wall mounted solar flood light should store the batteries under the light. If you cannot find it there, you will have to remove the solar light from the wall to access the rechargeable batteries. The staked solar flood lights will store batteries behind the flood light. It may require a Phillips head screwdriver to remove a screw or two first.
Solar string lights will have a battery box at one of the ends of the string lights. They often contain four AA or AAA rechargeable batteries. Since they are easy to access, most manufacturers require you to remove a screw with a Phillips head screwdriver. This protects against children getting access to the batteries.
Portable solar lights will have a battery compartment under the entire fixture, whether that is a lantern or a hanging solar light. This is either popped off with your thumb or will need a screwdriver to remove a screw.
Solar street lights will have a larger battery box to store a battery that is more sized like a car battery. Since these batteries are larger, it may be protected with a small lock. In that case, you will need to have access to the key.
Step Three – Identify What Kind Of Rechargeable Battery Your Solar Light Needs
There are two factors to consider when identifying the type of rechargeable battery your solar light needs. First, you need to know the type of battery. If you get the wrong battery type, it either won’t fit or won’t provide the right current and voltage for the light. This could lead to the light either not turning on or short circuiting.
Secondly, you should understand the capacity of the battery. This is measured in milliamps-hours and it is responsible for how much electricity a battery can store. So, a larger capacity means the battery can power a solar light for a longer period of time. Your solar light might require rechargeable AA batteries, but there is a range of battery capacities that you can buy.
We put together a great rechargeable battery buying guide that helps you get the best bang for your buck. It reviews each battery type, capacity, price, and customer feedback to bubble up the best battery options for each category.
Since you have already located the old batteries you can find the type of battery somewhere on the battery label. If the label is worn off, here’s a quick reference table that can help you identify the typical battery type.
| Solar Light Category | Battery Type | Battery Chemistry |
|---|---|---|
| Solar garden lights | AA or AAA | Nickel Metal Hydride (NiMH) |
| Solar flood lights | AA | Lithium Ion (Li-ion) |
| Solar string lights | AAA or CR2032 | Nickel Metal Hydride (NiMH) Lithium Ion (Li-ion) |
| Portable solar lights | AA | Nickel Metal Hydride (NiMH) |
| Solar street lights | Deep Cycle Gel | Lead acid |
It’s important to note that the chemistry for each battery in the table above is the recommended battery chemistry. Your current batteries could be using a cheaper chemistry that has a shorter life span and smaller capacity.
Step Four – Order The Rechargeable Replacement Batteries
Now that you know what type of battery you need, you can order that online. The chemical makeup of the battery doesn’t impact whether the battery will work or not for your solar light. However, it does impact the lifespan of the rechargeable batteries that you order.
Read through the best solar light battery reviews to help you make the most informed decision
Different chemical makeups will impact how many battery cycle counts the battery has before it starts degrading. For example, a lithium ion battery might have 2,000 cycles before it reaches 80% of its original capacity. Below is a graph that demonstrates how a battery loses some of its capacity every time it is discharged.
Step Four – Replace Batteries In Solar Lights
Your batteries finally arrived and you’re ready to put them in. Make sure your solar lights are turned off. Since you already know where the battery compartment is located, use the appropriate tools to open it up. Double check that the lights are turned off.
Remove the old batteries and install the new rechargeable batteries. Replace the battery cover and test the lights to make sure they work. If they don’t come charged, read our section on how to test solar light batteries to finish the test.
You’re not done yet! The old batteries need to be disposed of properly. If it was lead and cadmium battery, it contains toxic waste and can’t be thrown away. If it was a different type of rechargeable battery, it can be recycled instead of thrown away.
Small sealed lead-acid (SSLA) nickel-cadmium (Ni-Cd) rechargeable batteries have been coined universal waste by the Environmental Protection Agency. There are federal regulations on how to properly dispose of those batteries. By law, there should be a label explaining how to get rid of that battery type.
All other rechargeable batteries can be recycled so that the materials can be reused in more batteries. Call2Recycle is a free program that helps you recycle those batteries.
How To Test Solar Light Batteries
Now you know how to replace batteries in outdoor solar lights, but you may not need to replace them yet. Knowing how to test the rechargeable batteries in your solar lights will help you determine if you need new batteries. It will also help you make sure that the new batteries work.
The first test takes longer, but is the easiest testing method. You will need to place the solar panel in direct sunlight for at least 4 hours. Remember to keep the solar light component turned off. This will give even the older solar panels enough time to generate a sufficient amount of electricity for the batteries. Now turn the switch to the on position to see if the light comes on. If the light comes on, make sure it stays on for at least an hour.
The second way to test solar light batteries is the quicker option. But it requires you to have spare batteries laying around. Make sure the switch is turned to the off position and remove the old batteries. Block the solar panel from receiving any direct sunlight. Replace the old batteries with the same type of battery, though it does not need to be rechargeable. If the lights come on when you flip the switch, it means your old rechargeable batteries should be replaced.
When To Replace Your Solar Light Batteries
Rechargeable batteries typically begin degrading in total capacity after the first 100 battery cycle counts. Depending on the chemical makeup of the battery, there will be a 20% drop in capacity around the year and a half mark. Replacing the battery will depend on how long you need it to stay on. If you need the solar light for 8-10 hours every night, you may want to consider replacing the rechargeable battery every two years.
Of course, you may need to change the batteries much earlier if they don’t work. To better understand if the battery works, review the How To Test Solar Batteries section of this post.
How Long Do Solar Light Batteries Last?
A solar light rechargeable battery will last anywhere from two to ten years. This depends on the type of battery, capacity, and how it is being used. We put together a small table that helps you better understand the typical life of a rechargeable battery for a normal solar light condition.
| 100% Capacity | 90% Capacity | 80% Capacity | 70% Capacity | 50% Capacity |
| 0-6 months | 6-18 months | 18-24 months | 24-42 months | 60-120 months |
Learn more about the best solar batteries in the market.
Solar Rechargeable Batteries FAQ
How Do You Charge Solar Light Batteries?
You can charge solar light batteries one of three ways:
- Place the solar panel in direct sunlight for at least 4 hours
- Place the solar panel under an artificial light for at least 6 hours
- Charge the batteries in a wall outlet battery charger
Do All Solar Lights Use Rechargeable Batteries
All solar lights must use rechargeable batteries. The electricity generated from the solar panel is not consistent enough to power the light on its own. The solar panel also does not product the correct voltage required by the solar light. The battery is used to smooth out the transmission of electricity from the solar panel to the light.
Lastly, the rechargeable battery is used to store energy when the sun is not shining. Typically, solar lights are used in dark environments. They simply would not work if they did not store energy from the sun to be used at a later time.
How To Clean Battery Contacts On Solar Lights?
Remove the battery, as detailed in Step Two of the tutorial above. Make sure the solar light is turned off. Use a damp rag to clean the connectors that touch both sides of the rechargeable battery. Dirt and soot can get in between the contacts and the rechargeable battery, interrupting electricity flow between the battery and the solar light. When you’re finished, replace the batteries and turn the solar light back on.
Can I Recycle My Old Rechargeable Batteries?
It depends on the chemical makeup of the battery. In all cases, you should safely dispose of your batteries according to federal regulation.
Most rechargeable batteries, like the lithium ion battery, can be recycled at a local battery store. Your local recycling center should also have a battery disposal section. Lastly, you could use Call2Recycle to recycle your lithium ion batteries for free.
Some lead based batteries are considered universal waste and should be disposed of at a licensed waste center. You can find your local waste center through the Environmental Protection Agency website.
Can I Use Regular Batteries With My Solar Lights?
You cannot use regular batteries with your solar lights. The batteries will need to be recharged by the solar panel for later use by the solar light. However, you can use regular batteries to test the solar light. You can also use this technique to validate that the rechargeable batteries are not working.
Do Solar Powered Garden Lights Need Batteries?
All solar powered garden lights need rechargeable batteries. Though these may be small, they are included in any solar light application. So, without these batteries, the lights will not turn on. Even in direct sunlight, the batteries are needed to pass the electricity onto the solar light. If you accidentally use regular batteries, you could damage the solar panel and batteries.
Do Outdoor Solar Lights Need Rechargeable Batteries?
Outdoor solar lights will require functional rechargeable batteries in order to be recharged through the solar panel. Without the rechargeable batteries, the electricity created by the solar panel will not make it to the solar light. Using regular batteries could damage the solar panel and the batteries.