The Li-Ion Charge Cycle

摘要

Li-Ion batteries require a specialized charge cycle for safe charging and to maximize the lifetime of the cell. The battery is charged in two stages: constant current (CC), and constant voltage (CV). When the battery is below the full charge voltage, the current is regulated into the battery. In CC mode, the current is regulated to one of two values. If the battery voltage is very low, the charge current is reduced to a pre-charge level to condition the cell and prevent cell damage. This threshold differs with chemistry and is typically determined by the cell manufacturer. Once the cell voltage rises above the pre-charge threshold, the charge increases to the fast charge current level. The maximum suggested fast charge current for typical cells is IC (C = current it takes to drain the battery in one hour), but this current is also determined by the battery cell manufacturer. The typical charge current is -0.8C in order to maximize the lifetime of the cell.