How to Charge Solar Lights Without Sun? Time-Saving Tips!

Can you charge solar powered lights indoors? In the absence of sunlight during winter, how can you make your solar lights work more efficiently? Here’re practical ways you can do.

decorative small solar light after charging without sun

Outdoor solar lights enhance the beauty of your landscape. They are independent from the grid, making them eco-friendly solutions for reducing our carbon footprint. What’s more is you can eliminate electric bills for lighting your patio, lawn, garden, exterior and street with these outdoor solar lights.

Now, it is a challenge to keep solar lights burning during strong winter months when usually the sun stays hidden. Thankfully, decorative solar garden lights are lightweight and easy to handle, so you can easily bring some of them indoors to charge.

In this article, we’ll review some strategies for charging solar powered lights indoors and outdoors.


How Long Should Solar Lights Be Charged?
Can I Charge Solar Lights Without the Sun?
Can I Charge Solar Lights Indoors?
Will Solar Lights Charge On A Cloudy Day?
How To Charge Solar Lights Without Sunlight
How to Charge Solar Lights in Winter More Effectively

How Long Should Solar Lights Be Charged?

If you want to know how long is enough to charge your solar light with indirect sunlight, you must first know how it works and what it needs.

Here’s a video on how solar lights work:

Solar lamps work by photovoltaic energy conversion. They have photovoltaic cells (usually the black panel on top of the lamps) that convert the light from the sun to DC current. The current is then stored in the battery to power up the lamp at night.

For solar lighting devices to work best, they needed to receive direct sunlight for 4 to 10 hours. Take note that the solar panel should be away from shadows to get the most out of the sunlight’s rays. When the batteries are fully charged, your outdoor light can stay all night long.

For more robust outdoor solar lights such as solar street lights, charging would only take 6 to 8 hours. A fully charged solar street light battery can usually provide lighting for 5 to 7 sunlight-less days.

Hence, manually charging your solar lights with artificial lighting will definitely take longer time, say 8 to 12 hours.

Can I Charge Solar Lights Without the Sun?

Yes, you can definitely charge them even without the sun, although it will be less efficient to do so.

Since solar lights are sun-powered, you’d think they are only practical for sun-kissed areas like in Mexico. This is a common misconception.

If you live somewhere that rarely sees the sun, you can still install these solar lighting systems. Solar lights can even work better in winter. However, some of them may need to be charged with indirect sunlight when they don’t get enough solar energy to last for many days.

Note that this applies to smaller solar lighting system units that are usually used for lawns, patios, and pathways.

But if you have an AC Hybrid or a Wind Solar Lighting Solution, these solar systems can alternatively get energy from the grid or from the wind power during extreme emergencies when the sun is not available.

solar street light charging without sun on cloudy day
Off-Grid Solar and Wind Hybrid LED Street Light with Lithium Battery

For the context of this article, we’ll assume that you are using small-sized solar landscape lights that are topped with a solar panel and have simple design configuration.

Can I Charge Solar Lights Indoors?

For lightweight solar lights, you can definitely bring them indoors to charge. You can use regular light bulbs, or by placing them near windows. You can even charge them using your laptop or solar power banks if they are built with a USB charger. We’ll discuss these methods below.

Will Solar Lights Charge On A Cloudy Day?

When solar powered lights don’t get enough sunlight to fully charge, this doesn’t mean they are rendered useless on cloudy or winter days.

Take note that solar panels are designed to optimize energy harness during the day, so you need not to worry each time the sun doesn’t show up. The only downside you would face is there would be less energy stored in the battery. This means you can only use them for less than 6 days.

Hence, if you’re looking forward to running a grand garden event, and your solar string lights would deem you failure on these shadowy, cloudy days, perhaps you need to charge them first.

How To Charge Solar Lights Without Sunlight

Here are some of the easiest ways you can effectively and practically charge your solar lights without the sun.

1. Make Use of the Little Light During Winter/Cloudy Weathers

solar light charge indoors during rainy season
Photo credits from 12 Power Outage Hacks That Will Help You Brave the Next Winter Storm

You might think it uncanny to charge grid-free solar lights during gloomy, grey weathers, but did you know that solar panels charge more effectively in cold temperatures?

Although winters, rainy seasons and cloudy days may seem bad timing to charge solar powered lights because there’s no direct sunlight available, this is just a myth.

During these days, there’s still a small beam of light hitting the receptors of the PV cells of your solar lights.

These receptors receive, store and convert energy regardless of the distance and amount of heat generated in the environment.

Couple this with the good, cold temperature, the electrons inside the solar panels won’t have excessive electron movements.

And thus, it will render higher voltage difference giving more energy production.

Hence, even when the sun stays hidden behind the clouds, your solar panel lights will still get charged.

2. Make Use of Incandescent Light

charging solar panel light with incandescent bulb
Photo credit: How to Boost Solar panel Output

You can use incandescent bulbs to charge your solar panel lights. We know it’s kind of absurd to use energy from a hard-wired light to charge a supposed-to-be energy saving light.

But the point here is, some people do use outdoor solar lights as emergency equipment indoors in preparation for power outages. It’s like using rechargeable flashlights when power is going to be out.

Hence, if you need a substitute for direct sunlight, strong artificial lighting can do the job. This is because solar cells respond to both types of light as they run at similar wavelengths and spectrum.

This means that incandescent bulbs can charge any solar powered object you have such as solar watches, calculator or solar flashlights, the same way they charge through sunlight.

However, note that it takes longer to charge when you use artificial lighting, about 2 to 5 hours more.

To do this, just position the incandescent a few inches away from the face of the panel. The solar light can be charged for about 6 to 12 hours, depending on the wattage of the bulb. You can use a 40W to 100W to yield the best results.

3. Make Use of an LED Light Source

charge solar panel light with LED light
Photo credit: Ebay

You can also use an LED light to charge your solar lights. Doing so may render the same result, but because LED light covers a larger range of spectrum, it can be more beneficial than incandescent.

4. Use An Alternative Charging Method

Some solar LED lights can have an alternative charging method through a USB charger, allowing you to plug it to wall sockets or power banks. Although this option might cost you more than the previous options, you can use this opportunity if it’s more convenient for you.

How to Charge Solar Lights in Winter More Effectively

Here are some tips you can follow so that your solar lights can work more effectively during those chilly snow storms in the winter.

1. Remove Snow or Dust From the Solar Panel’s Surface

wipe solar panel light with cloth to charge efficiently
Photo credit: Quick & Easy Way to Clean, Renew & Restore Solar Pathway Lights

Snow accumulates on the surface of the panels, making it difficult for it to harness energy from the sun. To help it charge more efficiently during winter, remove the snow on the surface as much as you can.

For best results,

  • Wipe the solar panel surface with a microfiber cloth soaked with clean water.
  • Do not use detergents if it isn’t necessary as it may cause streaking.

Here’s how to properly clean solar pathway lights:

2. Reposition the Angle of the Solar Light to Receive More Light

repositioning the solar light to receive more sun
Photo credit: Wikihow

Make sure that the angle of the solar panels face the direction of the sun, especially during winter months as there’s less sunlight on these days. You may also want to reposition them somewhere that can receive more sunlight.

For best results,

  • Let them be charged for 8 to 10 hours under full sunlight.
  • Do not place them near shadows or under tall trees.

3. Make Use of a Mirror to Redirect Light to Your Solar Light

charge solar panel light indirectly with mirrors
Photo Credit: Researchgate

Using mirrors to reflect more sunlight to your solar lights is also an efficient way to get the most out of the sun rays during winter.

This is a labor-intensive method as you need to keep repositioning the mirrors throughout the day.

But at least you wouldn’t need artificial light to energize your solar lights.

Tips on using mirrors:

  • Look for mirrors that are bigger than the solar panels so they can receive more sunlight that’s possible.
  • Let the mirror stand in a diagonal position from the ground so you wouldn’t have to place it above the solar panel.

4. Switch Off Your Solar Light and Let It Charge For 72 hours

This is called deep charging the battery and you can do this once or twice a month so as to keep your solar batteries running more efficiently.


There you go! You see, there are many alternatives to charging your solar lights without direct sunlight. You can charge them indoors or outdoors.

We hope these simple hacks can solve your issue of charging solar lights. You can even apply these for other solar equipment and devices that have solar panels.

Want more solar lighting ideas and hacks? We have tons of solar energy articles, buying guides, and reviews at

5 thoughts on “How to Charge Solar Lights Without Sun? Time-Saving Tips!”

  1. Thanks for the article! The information are useful for me!
    It is not difficult to realize that solar technology actually does not have to rely entirely on the sun, we can rely on artificial lights on cloudy days, long winter or no direct sunlight.

  2. Can I detach the solar battery from spotlight and move the battery to a sunny position on my roof and extend the wire lead down to the light?

    1. yes, you can. In that case, recommend using the separate led head with the solar power system, the led light distance between solar power system maximum can be 5meters.

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