The WS4518D-6/TR is a single cell battery management IC made by Will Semiconductor. It is packaged in a WDFN-6-EP(2x2) RoHS compliant package. The IC provides various functionalities such as Over-Charge, Over-Discharge, Charge/Discharge and Charge Timer. It also has monitoring circuit for gas gauge and temperature monitor output. It supports Li-ion, LiFeP, LiPo, and Ni-MH/Ni-Cd battery types. The IC has a low quiescent current (1µA) and the operating supply voltage range is 2.7V to 6.0V. The IC is also equipped with a programmable I2C interface, making it suitable for various devices.