To prolong the service life of Li-battery, a traditional charging profile including a constant current (CC) charging first and then constant voltage (CV) charging is widely used. However, current CC/CV conversion methods face several challenges, including precise battery state monitoring, reliable wireless communication, or unavoidable cross-coupling issues. To address these issues, this paper proposes a novel wireless charger topology that enables a smooth transition from CC to CV mode without additional components addition or closed-loop control. A primary CLC compensation network is used to ensure the primary receiving current to be constant. Two parallel loops charge the battery together initially and CC output is realized. As the charging progresses, one branch will be cut off owing to the conduction characteristics of diode and constant voltage output can be realized for CV mode. Finally, an experimental platform with 2.6A/105V is established to validate the feasibility of the proposed topology.
Zhu et al. (Thu,) studied this question.