As Earth's resources deplete and energy costs rise, safety and pollution concerns grow. Solar energy, a safe and eco-friendly renewable source, gains attention. With advances in solar technology, solar lighting products become popular due to their environmental and energy-saving benefits. Solar-powered streetlights, garden lights, and lawn lights are increasingly common, and solar energy's role in street lighting improves. In this article, we'll discuss solar LED lights.

What are Solar LED Lights?

Solar LED lights use solar energy as their power source, charging during the day and lighting up at night without the need for complex and expensive wiring. The layout of the lights can be easily adjusted, making them safe, energy-efficient, and pollution-free. They require no manual operation and are stable and reliable, saving on electricity costs and maintenance. Solar LED lights are mainly composed of solar panels (including brackets), LED lamp heads, control boxes (containing controllers and batteries), and lamp posts.The parameters of common solar LED lights are as follows:

The working principle of solar energy 

Solar lighting operates by converting solar energy into electricity through the use of solar cells. During daylight hours, energy is stored in batteries and then used by the controller to power the electric light source at night, providing functional lighting.

What are the common types of solar lights?

The common types of solar lights include:

Important factors to consider before purchasing LED solar lights

Function and Voltage 

Regulation of LED Lights The function of LED lights is similar to that of voltage regulating diodes. Their working voltage varies around 0.1V, while the working current changes around 20mA. To ensure safe usage, LED lights typically use serial limiting resistors, which prevent significant energy loss despite changes in the light's brightness due to voltage fluctuations. By designing automatic boosting circuits or constant-current circuits, LED lights can regulate their power and avoid damaging the LED bulbs. 

Electrical Characteristics and Temperature Control of LED Lights 

The peak current of LED lights is around 50-100mA, and the reverse voltage is around 6V. It is essential not to exceed these ranges to avoid damage to the LED bulbs. When connected in reverse or when the peak voltage is too high, such as in the case of a battery running low, LED lights can easily surpass these limits. Temperature control is also critical since LED lights are not very tolerant of high temperatures. Even a 5℃ increase in temperature can reduce the light's brightness by 3%, so special attention is needed in the summer. 

Limitations of Parallel Connections and Optical Design of Ultra-Bright LED Lights

The working voltage of LED lights varies significantly, even for the same type and batch. Therefore, it is best not to connect them in parallel. If parallel connections are necessary, it is crucial to ensure equal current distribution. For ultra-bright LED lights, the light penetration is weaker due to their high color temperature range of 6400k-30000k. As such, special arrangements are necessary for their light arrangement. Static electricity can also significantly affect ultra-bright LED lights, so installation should include anti-static devices, and workers should wear anti-static wristbands. 

Design of Photovoltaic Energy Storage Capacitors 

The lifespan of solar panels can exceed 25 years, while that of ordinary batteries is only 2-3 years. Therefore, it is essential to include energy storage capacitors to ensure optimal energy storage and supply to the LED lights. The lifespan of energy storage capacitors can exceed 10 years, and their control circuits are relatively simple. However, they are more expensive, and their application is still limited by technological constraints. 

Design of Light Sensor Circuits

Light sensor circuits are necessary for controlling solar-powered lights automatically. While many people use photoresistors for this purpose, solar panels themselves are excellent light sensors. Therefore, it is better to use them as light-sensitive switches instead of photoresistors.

The Pitfalls of Solar Lanterns

• False advertising and low-quality components: Unscrupulous manufacturers falsely label parameters like power and reduce pole thickness, which are hard for customers to detect. This allows them to lower prices and disrupt the market.

• Chip brand and quality: LED chips directly affect the performance and price of lights. Some dishonest sellers use low-quality chips, counterfeit brand-name chips, or lower-grade chips to deceive customers into buying inferior products at high prices.

• Sacrificing scientific lighting system design to cut costs: Unscrupulous manufacturers may alter or even remove lighting systems to reduce costs, leading to issues like uneven brightness, "zebra stripes," or yellow rings. These problems are difficult to detect without professional testing.

• Poor heat dissipation design: The lifespan of LED chips decreases significantly as the PN junction temperature increases. Proper heat dissipation is crucial for ensuring the longevity and quality of LED lights. Unscrupulous manufacturers often cut corners in this area, leading to problems that may only become apparent after some time of use.

• Power supply quality: The price and quality of power supplies are closely related to their design and internal electrical components. Merely having a functioning light is not enough. Many products on the market use substandard power supplies.

• Excessive harmful substances in light sources: LED blackening is a common issue faced by many LED companies, mainly caused by the presence of harmful substances in the light components that negatively affect the light source's lifespan.

• Misleading concepts: Solar LED lights can typically have adjustable power usage. However, some manufacturers take advantage of customers' lack of knowledge by only mentioning illumination time, rather than power usage, to deceive consumers.