How to Charge Solar Lights Without Sun

Our forefathers must have fantasized about having the ability to store the Sun’s energy for use during the nighttime hours. Fortunately for us, this dream is not only a reality, but it has also come to be accepted as the norm by humans all over the world. Solar panels have revolutionized lighting technology and, in some cases, have literally lifted us out of the darkness.

Solar lights are a straightforward solution for the majority of homeowners. It’s simple to place them in a location with plenty of sunlight and wait for the battery to be fully recharged. However, depending on your geographic location, the season, and the weather, the amount of sunlight you receive may differ. In this case, you may have to be a little creative when it comes to charging your lights.

In this article, we’ll look at how to charge your solar lights without the use of sunlight, so that you can get the most out of your investment. There are three main approaches to the problem: using electricity, artificial light, or indirect sunlight are the three main approaches.

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How do Solar Lights work?

To understand how solar lights work and how to charge them without the use of the Sun, it is first necessary to understand how they work. A solar light is made up of three main components: a photovoltaic cell, a battery, and a light that are all permanently attached to each other. In the process of harvesting energy, converting it, and then emitting it for use in a garden, emergency situation, or pathway, there are several steps involved.

  • Step 1: Light enters the photovoltaic cell, and energy is collected in the mini solar panel by the wiring that surrounds it. This electricity is then used to charge the battery of the solar light.
  • Step 2:It is stored as chemical energy in the battery during the daytime by the battery. As soon as the battery is no longer receiving direct sunlight charging, it will begin to provide power to the light source.
  • Step 3: The system lights up the LED bulbs which draw energy from the battery until it’s exhausted or daylight hours resume. LED is an obvious choice for solar lights due to their ultra-low energy usage.

The Basics of Solar Cells

Photovoltaic cells and amorphous cells, both of which are used in solar panels, are capable of converting solar radiation into electricity. Specific types of visible light can only be converted into electrical energy by these cells, and they are only effective at doing so. For example, infrared and ultraviolet (UV) light do not contribute significantly to the generation of electricity.

In terms of energy production, the most efficient form of visible light is found in the range of violet to red, or in the wavelengths of 380nm (violet) to 750nm (red), respectively (Red). You can either harvest this light naturally (by utilizing the Sun) or artificially (by using artificial lighting) (using other electric lights).


This is frequently the simplest option because many solar lights are already equipped with a power plug or USB connector. You can charge the battery by simply plugging the light into a wall outlet or an external power source, completely avoiding the need for solar panels. Thus, the solar light performs in the same manner as a conventional wired or battery-powered lamp.

Camping solar lights are frequently equipped with a DC car charger adapter as well. Having this on hand when you’re out in the wilderness and don’t have access to a mainframe electrical system can be extremely useful in an emergency. If, on the other hand, you intend to use solar lights while hiking or camping, make sure to fully charge them beforehand. It only takes one hike that takes longer than expected or one time that you place the light in a shady spot to completely drain your battery.


Specifically designed to capture sunlight, solar panels are becoming increasingly popular. Other forms of visible light, such as sunlight, can still be used to charge the panels. There are many different types of artificial light, but on average, it is far less intense and effective when compared to naturally occurring sunlight.

While it may seem counterintuitive to charge an electric light with another electric light, there are some situations in which doing so may be beneficial in certain circumstances. In order to save energy, you can do things like charge your solar lights inside your home while you go about your daily routine. Once the sun has set, you can simply return them to their original location. As an alternative, if you do not have access to an electrical outlet or the Sun, you could charge your lights in a well-lit public area.

When it comes to everyday household lighting, incandescent bulbs emit wavelengths that are the most similar to those emitted by sunlight. Unfortunately, incandescent lights are becoming increasingly rare as more and more homeowners opt for more energy-efficient LED bulbs to replace them. Try to position your solar panel as close as possible to an incandescent light fixture in your home if you have one in your home.

The Importance of Lumens

Lumens are the units used to measure brightness. Choose an artificial light source with the highest number of lumens possible when charging a solar panel because it will be the most intense when charging the solar panel. Intensity like this will “mimic” the power of the Sun, assisting in charging your solar panel in the most efficient and timely manner possible.

The wattage of a household light bulb can be used to make a rough estimate of how many lumens it produces. Basically, a higher wattage corresponds to a greater number of lumens. As a point of reference, sunlight on a summer day produces approximately 10,000 lumens per square foot of surface area. This number is important because the closer you can get to it, the faster your solar lights will charge when exposed to artificial light.

Incandescent bulbs Fluorescent bulbs LED bulbs
Lumens Watts Watts Watts
250 25 4-9 3
450 40 9-13 4-5
800 60 13-15 6-8
1,100 75 18-25 9-13
1,600 100 23-30 16-20
2,000 125 28-40 20-25
2,600 150 30-55 25-28
LED’s are amazingly energy efficient close to 1/10 the watt usage of Incandescent

3. Indirect Sunlight

When you learn that solar lights don’t actually require direct sunlight to charge, you may be a little surprised. Even if you use your solar panels as an indirect source, they can still provide some level of charge. A bright but shaded location can be used in the event that direct sunlight is not an option due to weather conditions.

One way to increase the efficiency of your solar panels when exposed to indirect sunlight is to surround them with reflective surfaces or mirrors. Without having to physically move your panels, these will assist you in directing more sunlight into your solar panels. A mirror is the most effective option, but any large, flat, and white object will suffice.

To maximize the effectiveness of your solar panels, choose mirrors that are at least twice the size of your solar panels. This will ensure that the panel receives the maximum amount of sunlight possible. It is also recommended that you reposition the mirrors throughout the day to take advantage of the changing light.

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Charging your Solar Lights in Cloudy Weather

Isn’t it true that it’s a cloudy and miserable day, and there’s no way any sunlight will reach your solar panels? No, not in the traditional sense. A significant amount of sunlight can still manage to reach the Earth’s surface, no matter how bad the weather conditions are.

You can still get a decent or full charge for your solar lights even when it is cloudy outside, depending on the size of your solar lights. During a particularly overcast day, solar panels are only about 20% of their maximum efficiency compared to days when the sun is shining. However, this is based on the assumption that there are no cloud breaks during the day, which is extremely unlikely.

When dealing with inclement weather, it is recommended that you dry your solar panels on a regular basis with a soft cloth. Depending on how well your panels are sealed, precipitation can have an impact on how much light they receive and even cause damage to them.

In addition, you should position your solar lights so that they are directly facing the sun, as this will maximize their charging capabilities.

We have conducted extensive research and testing on the best outdoor solar lights. In this section, we’ll go over which outdoor solar lights rank highest in various categories, and which numbers 2 and 4 perform the best on cloudy days, among other things.

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3 Ways to Make Sure you are Getting as Much Charge as Possible

In order to get the most out of your solar panels when operating in less-than-optimal conditions, such as cloudy weather or under artificial light, you must make certain that you are harvesting every last ounce of available energy. After all, if you’re worried about whether or not you’ll have light tonight, it’s best to do everything you can to increase your chances of getting a good charge.

1. Angle your lights

Orienting your solar lights directly toward the sun or an artificial light source may provide you with that extra boost in charge to maximize your charge. You may not always have the option of moving fixed solar lights that are mounted to a wall or installed on a fence post, but you should try to be as creative as possible when it comes to lighting your home.

It is important to remember that the sun is at its most intense during the middle of the day. Keep this in mind when moving your solar panels because it can have a significant impact on the amount of charge your battery receives. It is important to remember to reposition your panels throughout the day, even if you put them out in the morning.

2. Keep your Lights at an Ambient Temperature

Another factor that has an impact on the efficiency of photovoltaic cells is the temperature. Extremely high temperatures should be avoided at all costs because they have the potential to damage or reduce the efficiency of your solar panels.

Anything above 87 degrees Fahrenheit will result in a reduction in the amount of electricity that can be produced. Keep solar lights away from dark surfaces when installing them because this will cause the lights to become hotter during the day. Do not place the solar panel too close to the bulb of an indoor electric light if you are charging your panels with one. This will cause the solar panel to become too hot and possibly cause a fire.

3. Keep your Solar Panels Clean

Keeping your panels free of dirt and dust will help to ensure that light does not become obstructed. When it comes to keeping your solar lights in good working order, a simple wipe with a mild soap, window cleaner, or even just some water will go a long way.

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Can you charge a solar light with a flashlight?

No problem – artificial light (for example, a flashlight) is capable of charging your solar powered devices. The brightness of the flashlight determines the rate at which it charges the solar light and vice versa.

Because an average flashlight emits 100 lumens, charging your solar light will take much longer than it would if you were outside charging your phone. If we compare the average flashlight to a cloudy day, it is 6.7 percent as powerful and 0.1 percent as powerful as a sunny day (measured in lumens), respectively.

So while sunlight is not required for solar lights, it is definitely beneficial.

Specifically, according to Philips (you’re probably familiar with the lightbulb manufacturers):

When it comes to indoor lighting, the average is 300-500 lumens, whereas outdoor lighting can range anywhere from 1500 lumens on a cloudy day to 100,000 lumens on a sunny day.

Can You Charge A Solar Panel With A UV Light?

In theory, a small portion of the ultraviolet A (UVA) spectrum of light could be used to charge a solar panel.

Because the UVA (315-400 nm) band of ultraviolet light falls just within the Red visible light spectrum, it is possible that a small portion of that light could be used to charge solar panels, but the process would be extremely inefficient and ineffective. Because they do not have a dark blue filter like other blacklight bulbs, UV-A blacklight bulbs with no filters are the only ones that should be used instead.

The wavelengths of the vast majority of ultraviolet light fall below the range of wavelengths used by solar panels today. The ultraviolet spectrum has wavelengths ranging from 100 to 400 nm, and as we have discussed in other sections of this article, the most efficient form of visible light for power generation is within the spectrum of violet to red, or the wavelengths ranging from 380nm (violet) to 750nm (red) (Red).