Due to the development of informationiza-tion, the electronic products are widely being used, such as cellphone, digital cameras and MP3 players. Nowadays, there are hundreds of different cellphone batteries for varied brands. This research is aimed at designing a low-cost charger which can also be applied in various types of betteries by using an installation of rotatable knob to adjust the chager in different voltages. The versatile chargers will replace different types of chargers in order to save money for buying various chargers. Finally, it will bring lots of benefits to people who will no longer carry the complexity of electro wires and chargers.