CSPL - CCCV Chargers For Lithium Ion Batteries

A CCCV (Constant Current, Constant Voltage) is ideal for small batteries. Initially, the battery is charged at Constant Current. When the battery is nearly full, its voltage reaches the Constant Voltage setting of the charger, and the current decays exponentially as the battery gets a finishing charge. In a small battery, the charger voltage is divided pretty much equally among the cells within it. For example, when charging a car battery, the Constant Voltage of 13.5 V is applied to the 12 V battery, each of the 6 cells within it getting about 2.25 V. If any cell is more charged, its voltage will be a bit higher, taking away some voltage from the other cells: for example, if one cell is at 2.5 V, the other cells will be, on the average, at 2.20 V.