Various embodiments are described herein for a dual-voltage charging system for electrified vehicles. In one example embodiment, the dual-voltage charging system comprises an integrated active filter auxiliary power module (AFAPM), the integrated AFAPM is applied as an active power filter (APF) to compensate low frequency harmonics in a high voltage (HV) battery charger when the HV battery is charging, and applied as a low voltage (LV) battery charger auxiliary power module (APM) when the HV battery stops the charging and starts to charge the LV battery.