This work describes the analysis and design of a 170W LCC converter for Lithium-ion (Li-ion) battery charger applications implemented with Gallium Nitride (GaN) technology. The solution uses an integrated System-in-Package (SiP) with two 650V enhancement mode GaN High Electron Mobility Transistors (HEMT) in Half Bridge (HB) configuration, the dedicated gate drivers and all the required protections. The LCC converter is designed to charge both 12V and 18V Li-ion batteries in CC/CV mode.