The full detection is arround 1/10th of the charging current. When the voltage is reached it will stay on 4.2v per cell and the balancer will do his job to steer the charging current through the right cells to get them equal. Meanwhile the charging goes on but the current will drop.

Charging balanced will be automaticly stopped when all cells are at 4.2v and the charging current is dropped to 1/10th of the programmed charging current.