Generally speaking, there are three charging methods for outdoor power staion: mains power, vehicle charger, and solar panel charging. In the outdoors, if we want to charge the outdoor power source, the solar panel is undoubtedly indispensable! 

Solar panels are devices that directly achieve photovoltaic conversion through the photoelectric effect or photochemical effect. Under conditions of abundant sunlight, they can continuously convert light energy into electrical energy and continuously supply power to outdoor power sources. For example, the StorBit A1000 outdoor power bank adopts MPPT technology and supports a solar input of 240W, and can fully charge 80% of the battery in the shortest 3.5 hours. 

Currently, thin-film solar panels that operate based on the photoelectric effect have become the mainstream in the market. The solar panels available on the market are divided into amorphous silicon and crystalline silicon. Among them, crystalline silicon can be further classified into polycrystalline silicon and monocrystalline silicon. The surface of monocrystalline silicon is dark blue, almost black, and the four corners of its battery cells are in a rounded shape, with no patterns on the surface; while the color of polycrystalline silicon is sky blue, more vibrant, and the four corners of its battery cells are square, with patterns similar to ice flowers on the surface. 

The order of photoelectric conversion efficiency for these three materials is as follows: monocrystalline silicon (up to 23%) > polycrystalline silicon (12-15%) > amorphous silicon (about 5%). Monocrystalline silicon and polycrystalline silicon basically do not generate current under low light conditions, while amorphous silicon performs better under low light due to its inherently low energy in such conditions. In summary, when choosing solar panels, monocrystalline silicon materials should be.

The most important factor in choosing solar panels is the power of the panels. Generally speaking, the power of the solar panels is directly proportional to the area of the solar cells. The larger the area, the greater the power. However, in reality, a balance needs to be found between the power of the solar panels and the portability of the solar charger. Usually, we believe that the minimum power of the solar charger should not be lower than 0.75W. The secondary power solar panels can generate 140mA of current under standard strong light conditions. If the charging current is lower than the secondary power, the solar panel will basically have no significant effect. 

So, how should we choose the most suitable solar panel based on the existing outdoor power supply? 
First of all, we need to know the maximum solar input power that the outdoor power supply can support, and then select a matching solar panel with the same power. Secondly, we also need to pay attention to whether the rated maximum current and voltage of the solar panel are within the range specified by the outdoor power supply.If the current or voltage is too high, there is a risk of damaging the outdoor power supply. Under the same power output, is it better to choose a solar panel with a larger surface area? 

This is not necessarily the case. The area of the solar panel chips is not exactly the same as the area of the solar encapsulation panel. Because some solar panels, although they have a large area, have a relatively sparse arrangement of solar chips with wide gaps. As a result, the power of the solar panel may not be high, but the weight increases, making it inconvenient to carry, and it actually doesn't offer enough benefits. 

There are numerous types of solar panels available on the market. By keeping the above points in mind, you can basically select the appropriate solar panel for your outdoor power station! For more related knowledge about outdoor power supplies, we will continue to share in the next episode.