Capacitor leakage current refers to the current leaking out from the circuit when the rated DC voltage related to capacity is applied. Capacitor leakage current is the current leaked out from the capacitor after applying the rated DC voltage. Its main sources come from electrolyte medium and conduction performance of components in the capacitor. With the increase of time, leakage current will reach a stable value. It is related to temperature, size of capacitor and characteristic of dielectric medium.