A system for charging an electrically powered vehicle comprises a DC battery; and a current exchange controller. The current exchange controller is configured for receiving a supply current from an off-board power source and determining a desired current exchange characteristic. The current exchange controller is also configured for determining a modulation scheme for providing an exchange current that exhibits the desired current exchange characteristic; and modulating the exchange current in accordance with the modulation scheme so as to deliver an exchange current exhibiting the desired current exchange characteristic. The modulation scheme is configured to meet one or more criteria based on annoyance.