Functions of different components
Solar panel: Converts sun light into electric current. Usually, solar panels in gadgets range from 0.2 Watts to 2 Watts. It is very difficult for a common man to know what the panel size is of the gadget by looking at the panel. Most of the gadgets are rated in terms of daily load power in hours. This is the best way to rate the gadgets.
Batteries: Usually, NiCD or NiMH batteries are used in gadgets. These batteries are lighter in weight and are more stable in terms of voltage. Also, these batteries are generally commonly available and therefore can be easily replaced.
Note: Solar gadgets do not need controllers as the size of the solar panel is very small. Usually, if the panel size exceeds 10W, then it is beneficial to connect a controller.
Reliability: Due to minimalist design of the gadgets using only the components of long life, gadgets usually are quite reliable. In case of failures, then just by replacing batteries, you can usually revive the gadget back into working condition.
Viability: Solar panel takes up a large share of the system cost. And, it is the solar panel which makes the electricity. All the gadgets are very competitively priced and are always good to have for emergency needs.
*Components are of energy saver types. Apex has a ready stock of most of these components.
