A method and apparatus for fast charging a battery with optimal charging. In an arrangement, a system includes a battery charger for applying a voltage to a rechargeable battery; and a controller coupled to the battery charger and monitoring at least one of a battery voltage, a battery temperature, and the current flowing into the battery; wherein the system is configured to apply a charging current from the battery charger by calculating an open cell anode voltage and an anode resistance of the battery, and determining the charging current. In additional arrangements, lithium ion plating is prevented by the charging current. Additional methods and arrangements are disclosed.