How Long Do Solar Lights Take to Charge?

By Matthew Joseph Nandirio •  Updated: 01/06/23 •  7 min read

The amount of time it takes for solar lights to charge depends on several factors, including the type of solar panel and battery used, the amount of sunlight available, and the age of the solar light.

On average solar lights can fully charge themselves within 4 – 6 hours by direct sunlight to their maximum capacity.

here is a table showing charging time for different solar light types.

Type of Solar LightAverage Charging Time
Solar garden lights6-8 hours
Solar flood lights8-10 hours
Solar string lights6-8 hours
Solar street lights10-12 hours
Solar motion sensor lights6-8 hours
Solar deck lights6-8 hours

By the way, I have done several tests with three different solar lights to make sure the time is taken to charge them.

my 6 different solar lights and their solar panel placements

The above photograph has my new and old solar lights. I have discharged all of them and collected them to test the time taken to charge them.

different types of solar lights top view

This is the top view of all the solar lights and their respective solar panels.

my two garden solar lights charging under the sun

These two solar garden lights are new ones. So I added them under direct sunlight and started measuring the time to fully charge them.

It took only 4 hours to fully charge them.

garden solar light in action after fully charged under the sun

The above photograph shows how the LED in the garden light goes on when I artificially simulate the nighttime.

These garden lamps are pretty cheap. so their light intensity is kinda low.

New Garden solar light charging status check after they have been charged under the sun for 4 hours

The above video shows the new garden solar lights are in action after charging for 4 hours.

my two portable solar lights charging under the sun

Similarly, I added these two portable solar lamps to charge under the sunlight as well.

But these lamps are not easy to charge with solar light. Since their solar panels are small the time taken to charge is higher.

Further, these solar lights employ lead-acid batteries. They take a lot of time as well. You can find more details below sections as well.

By the way, you can watch this video to see how these portable solar lights are charging. Their charge indicator is lighting up under sunlight and goes off once I cover the solar panels.

These portable solar lamps took 7-8 hours to charge to a considerable amount of light intensity.

portable solar lights charging under the direct sunlight and the charging process check

Same way, I recorded the time took to charge my wall-mount motion-activated solar lamp charging time as well. They took around 6 hours to fully charge.

You can watch this video to see the light intensity after the charge.

old wall mounting solar lamp fully charged after 4 hours fo charging

How long do new solar lights take to charge?

You’re a new user of solar lighting systems. You are finding out how long it takes to charge the solar lighting system.

The photovoltaic effect is responsible for solar lighting systems. Due to this, maximum sunlight hours are necessary to recharge solar lights in your lighting system.

solar light charging mechanism

Experts say new solar lighting can recharge using direct sunlight within 4 to 6 hours.

However, it is recommended, you should charge the batteries for at least 8 hours under direct sunlight to improve their capacity.

Remember to do that before using them for the first time.

Now you know how long it takes for your solar lights to charge. Let’s examine what factors can affect your solar lights’ charging time. 

How to Charge Solar Lights for the First Time?

Charging solar lights for the first time is a simple process.

All you need to do is place the lights in an area with direct sunlight and allow them to charge for the recommended amount of time.

You can follow these steps to charge your solar lights for the first time:

  1. Place the solar lights in an area with direct sunlight: Solar lights need to be placed in an area where they will receive direct sunlight in order to charge effectively. This may be on a near windowsill, on a tabletop, or in a garden bed.
  2. Then allow the solar lights to charge for the recommended amount of time: Generally, solar lights should be allowed to charge for at least 6-8 hours for the first time.
  3. Test the solar lights to ensure they are working properly: Once the solar lights have charged for the recommended amount of time, you can turn them on and test the light brightness.
  4. Continue to charge the solar lights as needed: Solar lights will typically need to be charged regularly in order to continue functioning properly.

What factors affect the solar lights charging time?

1. Type of the battery in solar lighting system

The Lead acid battery has an assumed 85 % efficiency and is not efficient in electricity storage.

But in contrast, Lithium Ion (Li-ion) batteries have a higher efficiency rate, such as 99 % charging efficiency. And it also has minor discharge loss.

The Lithium Iron Phosphate (LiFePO4) battery recorded an average efficiency rate of 92%.

solar battery types

The traditional solar street lighting systems worked with lead acid batteries, but nowadays, novel lighting systems are facilitated with lithium-ion or LiFePO4 batteries.

So depending on these battery types, the charging time will differ.

2. Number of batteries in your solar lights 

The charging efficiency will affect the number of batteries included in the solar lights. 

Your solar lights take too much time to recharge, meaning they could have more than one battery inside them.

Usually, this happens to large-scale solar lights.

Because the more batteries included need to charge each of them individually, a higher number of batteries means higher efficiency and a higher charging time in solar lights.

3. The type of the solar panel

The panel type is another consideration for improving the charging rate of your solar lights.

Typically, major 3 categories of solar panels are available in the market: monocrystalline, polycrystalline, and thin-film solar panels.

solar panel types

According to that, monocrystalline panels have higher efficiency and give you a higher battery charging rate rather than polycrystalline panels.

However, they do cost higher than the others.

So polycrystalline panels can be seen in many common low-cost solar lights.

But the efficiency is limited hence it takes a longer time to charge the solar lights.

4. The size of the solar panel

The larger panel size can absorb a high amount of solar radiation and generate higher electrical power.

That means the larger solar panel can faster recharge your solar lights more than smaller solar panels.

different size of solar panels

5. Orientation of your solar panel

The other factor that can affect the charging rate of solar light is the intensity of sunlight strike on the solar panel surface. Otherwise, the sitting and tilt angle of the panel affect its charging speed.

That means if your solar panel is located in a shady place, it will not absorb maximum sunlight for power generation and will take a long time to recharge the batteries.

Your solar panel should be installed south facing can trap more sunlight during the daytime. And also, the tilt angle should be varied from season to season.

solar panel tilt angle

6. Weather conditions

Weather is also another primary consideration you want to take into account in installing your solar panel as well as solar lights. 

Because the cloudy or rain weather in your area will reduce the power generation from your solar panel and take too much time to recharge the batteries in solar lights.

different weather conditions

For that, always ensure before installing your solar lights that you can obtain maximum solar radiation for maximum recharge efficiency.

Some solar lights are specially designed to work with cloudy or rainy weather. But some of them are not compatible with these harsh weather conditions.

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