The trick when buying super cheap solar lights

Trên các trang mạng thương mại điện tử được bày bán nhiều mẫu đèn năng lượng mặt trời có giá bán khá rẻ so với các mẫu mã tương tự do các công ty, cửa hàng phân phối uy tín cung cấp. Chẳng hạn, một mẫu đèn 30W giá 120.000 – 150.000 đồng, đèn 100W giá khoảng 400.000 – 600.000 đồng hay các mẫu đèn 200W giá chưa tới 1 triệu đồng. Trong khi đó, sản phẩm có công suất tương đương của các công ty phân phối uy tín giá cao hơn gấp 3 – 5 lần. Ví dụ, đèn 24W – 50W do đơn vị phân phối SumoSolar cung cấp có giá 600.000 – 900.000 đồng, 100W do Givasolar phân phối có giá 1 – 2 triệu đồng. Các mẫu trên 200W giá đều từ 1,5 triệu đồng trở lên.

Các sản phẩm giá rẻ này được quảng cáo là chống nước, “siêu sáng" với thời gian từ 10 đến 12 tiếng, tuổi thọ đèn trên 50.000 giờ. Đèn có kèm điều khiển từ xa. Một số mẫu tích hợp cảm biến ánh sáng để tự động bật/tắt khi trời tối, hoặc cảm biến phát hiện chuyển động đi qua. Chúng có điểm chung là không có tên thương hiệu, chỉ ghi chung chung, không có thông số kỹ thuật chi tiết hoặc được  “thổi phồng lên", gọi chung là “Solar Light" hoặc “Solar Lighting".
>> Pin năng lượng mặt trời

The structure of the lamp includes a solar panel that collects solar energy - absorbs light and converts them into electricity; LED lights with the number of bulbs depending on the capacity, such as 270 LEDs (100W), 143 LEDs (60W), 110 LEDs (40W), 72 LEDs (25W) and a Li-ion battery or a battery to store electricity.

Among them, the solar cell is the most important part. The quality of today's panels is mainly based on photovoltaic cells (solar cells), which are divided into four types A, B, C, D with 24 levels. Class A includes levels 1 - 8 with the best quality and highest power generation efficiency, followed by B from 9 to 16 and class C with 17 - 24. Panels outside of level 24 in category D have poor quality and ineffective.

Mr. Binh, a technician of a solar lamp trading company in Ho Chi Minh City, said that some factories in China often buy waste battery models of type D by "kg" from many different sources. , then filter usable photovoltaic cells to combine into panels and sell them on the market at a very cheap price. “Sunlight models cost less than 200,000 VND, but are integrated with many features and advertised that lighting time of more than 5 hours is impossible. These types can use type D batteries, "said Binh.

According to Mr. Binh, the panels must go through quality inspection steps before being sold on the market. However, some places will skip these stages to save costs, so the selling price will be much cheaper.

Using cheap batteries has many potential risks. According to Mr. Binh, panels assembled from discarded photovoltaic cells will quickly age and rapidly reduce their efficiency of generating electricity. Since the photovoltaic cells are coupled in series, failure of one cell will damage the entire panel. Damaged panels will cause pollution when discharged into the environment.

Thu Ngô, một chuyên gia về điện mặt trời, cho rằng pin là yếu tố quan trọng trên các loại đèn năng lượng này, do chất lượng pin sẽ ảnh hưởng đến thời gian chiếu sáng của đèn vào ban đêm.

Đối với đèn năng lượng mặt trời dân dụng, bộ lưu điện thường là pin Li-ion với dung lượng 2.000 đến 10.000 mAh. “Tương tự pin cho các thiết bị điện tử khác, pin Li-ion cho đèn năng lượng mặt trời có nhiều loại với chất lượng khác nhau tùy theo nguồn gốc sản xuất", anh Thu nói. “Pin là bộ phận dễ xuống cấp nhất. Ngoài thời gian chiếu sáng thấp, xuống cấp nhanh, người dùng có thể gặp phải nguy cơ cháy nổ, nếu pin không đạt chất lượng".Many people who buy cheap solar lights have to throw them away because they do not meet expectations. “I bought a solar light for 150,000 VND, with a capacity of 45W, advertised as being able to light up for 8 hours continuously. But after about 2 to 3 hours, the light turned off by itself. After using for a month, the lights flicker, sometimes bright, sometimes dim, very annoying", account Dat Nguyen commented in a group about this type of light on Facebook. “I bought a 100W lamp for 400,000 VND, advertised as waterproof. But after a rain, the lights don't come on anymore. When I removed the inside, I saw that the components were full of water," Hoang Nguyen account said.

In all cases of buying electronics in general and solar lights in particular, users should choose branded products on the international market or those with representatives and agents in Vietnam.

With solar lights, Thu noted that in addition to the panels, users need to pay attention to the device's water resistance because these lights are usually used outdoors, rarely shielded. “If the water resistance is poor or there is no waterproof feature. When it rains, the lights may short circuit or even burn," Thu warned.

+ Don't think of a high wattage light as a better, brighter light, but Truth: The luminous flux (instead of wattage) of an LED bulb represents the total amount of light emitted by the bulb. The higher the luminous flux value, the brighter the bulb.

+ The 3 most important parts of the lamp are the led light, the battery plate and the storage battery. So when buying a lamp, you need to compare all three of these parameters, but don't focus on the power of the lamp, just think high power is ok. The battery with a large capacity, the faster the ability to collect energy, the more. The larger the battery storage capacity, the longer the lighting time. All three must balance each other to create a good lamp.

It must be affirmed, hitting on the cheap mentality, Chinese manufacturers have created LED products that defy all physical limits, super large capacity, 12 hours of continuous light as advertised. The images of the lights above, you can meet anywhere on e-commerce websites. And we also affirm that the types of lamps that can be overridden with wattage account for 99% of the popular market. Or maybe they are using a storage technology in outer space, beyond the understanding of 21st century science in the field of Storage Batteries as shown below.

Thus, a storage battery of 100W x12h = 1200Wh is required, equivalent to a 3.2V375ah or 12V100AH ​​battery block.

But the vast majority, the above seamless lamp models only have a battery capacity of 3 to 5 tablets of 32650 3.2V4.5Ah-5Ah, ie the total capacity is 3.2V15ah- 3.2V30Ah, which is less than 1/10 of the total capacity. with the information on the label. And the included solar panel has a capacity of only 20W-30W
The lamp is recorded at 120W, but the storage battery is only 3.2V15ah, which means the actual led power is only 4w, so it can run for 12 hours continuously.

And of course, they are still bright and bright because the power of the leds of these lights is only 5W - only suitable for very low criteria in lighting.

By hitting the low price mentality, it must be recognized that the above products have been equally successful in Vietnam, but the lifespan of these devices is only very very average and has a lifespan of no more than 1-1.5 years of use. use

But LED systems, independent monitoring and lighting projects are always built with very high parameter criteria and are precise in terms of power.

+ Compare lamp materials; lamp aluminum shell, or plastic shell

+ 1 more factor why you should buy lights from reputable units, because you can rest assured that if the lights have any problems, they will be returned and guaranteed.

The eternal saying is still true "You get what you pay for", so don't be greedy and make the wrong choice.