Development of Portable Solar Device for Charging of Li-Ion Battery of Mobile Phone
As mobile phone became necessary thing in contemporary life there is a need to enable fast and easy charging of Li-Ion battery of 3.7 V in every place. Today most mobile phones have USB port by which mobile phone battery is charged. It is because of the reason that all computers have USB port. In that way it enables that user does not need to bring a charger with self to charge mobile phone battery. It is enough that user has computer beside self. USB port has 4 pins: 2 pins are dedicated for transfer of digital data and 2 pins are dedicated for power supply of 5 V. Battery of mobile phone is Li-Ion battery and its nominal voltage is 3.7 V. Because of that, power supply of 5 V from USB port is quite enough for charging of mobile phone battery. In this paper is presented portable solar charger for devices with Li-Ion battery of 3.7 V. Portable solar charger enables charging of Li-Ion battery in the places where there does not exist electric power source. Device has 2 rechargeable NiMH batteries type AA which can be charged by solar panel or by USB port. Portable solar charger has electronics which raise voltage from these 2 batteries to voltage of 5 V which is needed for charging Li-Ion battery.