Yesa Technology Co., Ltd.

Our power battery group is composed of Battery BU in Darfon Electronics Corp., Keyseg Aone Technology Corp. (Taiwan area) and Yesa technology Co., Ltd. (Shenzhen). - Darfon Electronics Corp. ( is a public company in Taiwan area and established the Battery BU in 2009. We're the manufacturers of batteries for power tools and laptops and undertake OEM for the world-wide brand names - Keyseg Aone Technology Corp. (Taiwan area) is the R&D center of our group, working for lithium phosphate battery solutions and battery solutions recommended by A123 Systems. A123 Systems is the world first lithium phosphate battery supplier, while Keyseg is the designer and center of A123 battery solutions and prototypes. - Yesa technology Co., Ltd. ( is for sales promotion and offers battery solution in Shenzhen and provides prototype support for battery projects.