When away from home and power outlets during a camping trip or another long journey, a solar battery pack is a great solution to ensure that all portable devices - from cellphones to laptops to Android tablets - stay fully charged. This type of battery charger uses solar energy instead of electricity to stay charged, and typically offer at least double the power needed for a smartphone. This single portable device makes camping trips much safer, and the portable nature of many banks means that you won't have to sacrifice very much space in your backpack.
What Is a Solar Power Bank?
Just as the name suggests, a solar power bank is a battery power storage unit that gets its energy from sunlight. These kinds of banks are especially useful during camping trips when there are no electricity sockets to be found, but keeping charged equipment for emergencies is necessary. When deciding to purchase a solar power bank, make sure that you’ll have plenty of sunlight to charge it, and that when you’re not outside you’ve got a way to charge it from an outlet. While many of the banks on this list can be fully recharged with sunlight, it’s often advertised as more of an emergency option and not the intended primary source of power.
For many, the most time efficient way to get full charge is to let the bank power up while connected to a wall outlet in the home. Still, solar power banks are an invaluable investment for anyone who spends lots of time away from electricity while still needing plenty of electronic devices.
How to Choose the Best Portable Charger?
When choosing a portable charger there are two important attributes you need to keep an eye on:
Power capacity is the total battery capacity of the power bank. A power bank with high power capacity can give your phone multiple charges. The higher the power capacity, the more charges it can give your device. Power capacity is specified in mAh or milliampere hour.
Output amperage is the 'strength' of the port(s) of the power bank. High amperage means it's strong enough to charge large devices like tablets. The output amperage of the power bank needs to be at least 2A (ampere) to charge tablets and even stronger for laptops. For smartphones, 1A will do the job just fine. But the higher the amperage, the faster it charges. Power banks with multiple outputs usually have varying amperages, so pay close attention to this when choosing one.
Solar Panel: Currently solar batteries on the market are classified into amorphous and crystalline silicon (polysilicon and monocrystalline silicon). According to research and analysis, monocrystalline silicon has the best photoelectric conversion rate. (up to 17%), and follows by polysilicon(12-15%), at last amorphous silicon. In comprehensive view, it is appropriate to use monocrystalline silicon or polysilicon for solar cell materials. The power of solar panels is proportional to the area of solar chips, and in general, the bigger the power of solar panels the better, so the current generated under the sunlight is large and can quickly fill its built-in battery. But in practical applications, a balance point needs to be find between power and portability. We believe that the minimum power of solar charger can not be less than 0.75w, 140mA can be generated with this generator under standard light intensity. Current generated under general sunlight is about 100mA, if less the charging current may be too weak to achieve the expected effect.
Battery: As the use of solar energy charger differs a lot from that of ordinary electronic products, the requirements of the built-in battery is also high. It's recommended to adopt lithium polymer battery, compared to common lithium battery. Polymer lithium battery into the colloid, the degree of activity is much smaller than the liquid lithium-ion battery, it will not produce an explosion. And in order to adapt to different environment, lithium polymer battery must be high temperature treated to improve the battery temperature limitation.
Circuit: It is mainly responsible for two aspects of the functions: 1.Store the current generated by solar panel to reduce waste as mush as possible; 2. When supplying power to devices, transfer as much as possible the power to mobile phones etc, and waste as little as possible on the circuit. So the above two indicators must be taken into consideration when choosing solar power charger. The secondary conversion rate (the efficiency of the electrical storage generated by the solar panel to the battery) and the discharge efficiency (the efficiency of the electrical input in the built-in battery to the charging device required) these two indicators are the higher the better. In general,The secondary storage efficiency can reach 95%, discharge efficiency can reach more than 83%. Another important criterion for measuring the quality of the control circuit is whether the control circuit has made various protections. A good solar charger, its control circuit should have: Overcurrent protection (when the current is too high can automatically limit the current, will not damage the charging device).
Overshoot protection (when the battery reaches the set limit, it will automatically stop the battery charge, so as to eliminate the battery damage or even explosion - fried possible), over-discharge protection (mainly used to protect the battery, to avoid the depth of discharge and Battery damage), temperature protection (when the control circuit temperature exceeds the set temperature, the charger will automatically stop working to protect the battery).