This paper discusses and presents the implementation of a boost converter as power electronic interface to be used with the thermoelectric generator (TEG). The common application for such system is the battery charger. The boundary conditions for battery chargers include the charging current and battery voltage limits which have to be respected throughout the charging process, while the maximization of the power generated from the TEG is a global target that is desired to be met as much as possible. Coordinated control algorithm that collectively combines these constraints is the main focus of this work. Novel global control algorithm is proposed and verified in this paper with detailed analysis that shows the effectiveness of the proposed algorithm. Dual control loops for the voltage and current of the boost converter will be designed and analyzed to satisfy the source and load demands. Maximum power point tracking (MPPT) mode, power matching mode and voltage stabilization mode will be integrated in the control algorithm of the battery charger. This paper puts a schematic design for a system that harvests energy from a thermoelectric generator bank of a TEG1-12611-6.0 TEG modules in order to charge a battery bank of Samsung ICR18650 Batteries using constant current (CC) and constant voltage (CV) charging profiles.