Method and Apparatus for Fast Charging Li Based Rechargable Batteries

A method and system for charging a rechargeable battery, such as a Lithium based battery, by applying a voltage charge signal, and monitoring a battery charging current and a varying internal resistance of the battery and the changes in open circuit voltage of the battery. The voltage charge signal is dynamically established as a function of the determined varying internal resistance of the battery during charging and the changes in open circuit voltage of the battery. The voltage charge signal is a function of a state of charge (SOC) of the battery.