By the market. Since neither the current national standard solar charger lack industry standards, resulting in significant differences between the market price, the quality varies greatly. I have found that even with the market down more than 40 solar charger in the sales block, and also known as 'the candle, light, bright can charge.' So in the end what kind of solar charger, solar charger it be considered good? Solar charger is required to achieve the criteria for what kind of easy to use it? I would like to engage in solar photovoltaic products based on their own (including the solar charger) more than ten years of experience, to express their my humble opinion.
Before discussing this topic, it is necessary to review what we learned in junior high school's 'law of conservation of energy': energy will not only destroy, not creation, it only from one form into other forms, or from a object to another object, while in the process of transformation and transfer, the total energy remains unchanged.
With this knowledge reserve, we now have the basic common sense, and so he can be unscrupulous merchants of the so-called 'candle light, bright light can be as long as the charge' argument as a humorous joke or heard.
Evaluation of a solar charger or whether it is practical is a good product mainly depends on three aspects:
Currently the market is divided into amorphous silicon solar cells and crystal silicon. Which can be divided into poly-Si and silicon. Material from the photoelectric conversion efficiency of three terms are: silicon (up to 17%)> poly (12 ~ 15%)> amorphous silicon (5%). However, crystalline silicon (silicon and polysilicon) is basically in low light will not have currents, amorphous silicon-based low-light good (in low light energy of the already small). Therefore, comprehensive view, it is appropriate to single crystal silicon or polycrystalline silicon for solar cell materials.
Next we want to focus the power of solar panels is, in general, solar panels with solar power is proportional to chip area (the area of solar cell chip is not exactly the same area of solar panel package, as some solar While panels, but solar energy gap is very wide array chip, this is not necessarily high-power solar panels. such as the VSC-03 Although our solar panels is not, but the chip closely arranged, in the relatively small size also realized 0.75w power). In general, solar panel power is the better, so that large currents produced by the sun, can quickly be built-in battery is full. But in reality, the need for solar panels and solar power portable charger, find a balance. In general, we believe that solar power charger can not be less than the minimum 0.75w, (the power of solar panels in standard light intensity under 140mA of current. Arising under the sun in the general current of 100mA or so) if less than the power charge current is too small, basically no significant effect.
If solar panels are charger front-end part, responsible for collecting solar energy and solar energy into electricity, then the control circuit is the hub of the entire product. It is mainly responsible for two functions: First, to produce the current front-end storage to the built-in battery which as far as possible eliminate or reduce the waste to a minimum; second is when the charger for charging mobile phones and other devices, as many as possible will be within The battery in the power output to the mobile phone and other devices, but as little as possible power consumption will be online on the road. Unfortunately, due to cognitive or technical problems, domestic manufacturers of solar charger control circuit design optimization did not arouse enough attention, resulting in production out of less practical solar charger: front-end can not store the current generated to the battery; built-in rechargeable battery for mobile phones and other devices when a large part of the current waste line the road, unable to enter the charging device.
So consumers are choosing solar charger, you need to pay more attention to what these two indicators: Second conversion rate (front-end generated electricity stored in battery efficiency) and discharge efficiency (built-in battery in the electrical input to the need to charge the device efficiency). The two efficiency is better. In general, secondary storage efficiency can now do a very good 95%, discharge efficiency is 83% or more. Produced by the standard solar chargers is designed for.
Control circuit to measure good or bad is another important criterion: whether to do a variety of control circuit protection. In general, a good solar charger, control circuit should have: over-current protection (when the current is too high can automatically limit, will not produce damage on the charge device), overshoot protection (when the battery reaches the set the limit, will automatically stop charging the battery, so as to prevent battery damage or even the possibility of an explosion), over-discharge protection (mainly to protect the battery, to avoid deep discharge and damage with batteries), temperature protection (when the temperature control circuit more than set temperature, the charger will automatically stop working to protect the battery). If the control circuit on the protection of not doing or not doing much, it would be to shift the risk of quality solar charger needs charging digital devices such as mobile phones, it is likely losses to consumers. SunTech as we develop one's own solar charger, the first thought is how to guarantee security. In this regard, we a lot of effort.
As the solar charger with the ordinary use of the environment of electronic products are different, solar battery charger on the built-in demand is highest. But this is just easy to forget where the consumer is also a lack of social responsibility of the manufacturers of some easy tricks place. In the market, a similar capacity battery prices may differ several times, so some of the cottage manufacturers to aim at the piece of the profits, many very low-cost chargers are used in secondary batteries refurbished battery, good point is the use of battery products in the B, C batteries products. Such a short battery life is not that consumers are likely to risk the personal security.
Solar battery charger built-in lithium polymer battery should be better, compared to normal most common lithium battery (lithium ion), lithium-ion polymer batteries fitted into the gel, the level of activity is much smaller than liquid lithium-ion battery will not explode. And for the application of solar chargers use of the environment, the best high temperature processing polymer battery to improve battery temperature limit.
Finally, note that the shell surface and its accessories. The solar charger on the market common plastic shell-based, surface treatment are mainly light oil, rubber, paint, UV. Light oil prices were relatively cheap, while the surface prone to scratches. Rubber paint feel very comfortable, but with increased use of time would be Paint Falling off. UV generally only in high-end brand mobile phone use is very expensive.
If the solar charger with DC adapter, DC adapter and more concerned about quality is necessary. After all, this relates to the product and personal safety.