Abstract: A charging apparatus includes a power requirement unit and a power supply unit. The power requirement unit has a first sensing module and a first control module. The first sensing module senses an electric parameter value of a load. The first control module receives the electric parameter value. The power supply unit has a second control module and a power switching module. The second control module receives the electric parameter value to switch the power switching module according to an accumulated difference value produced by the electric parameter value and a target electric parameter value, thereby controlling the electric parameter value to be equal to the target electric parameter value.