Methods and apparatus are provided for charging a high-voltage battery of a hybrid electric vehicle. The high-voltage battery charging apparatus comprises a battery charger configured to provide electrical energy, a battery module configured to store the electrical energy provided by the battery charger, and a high-voltage bus coupled to the battery charger and the battery module, which is configured to transmit the electrical energy from the battery charger and battery module to the electrical system of the hybrid electric vehicle. In addition, the high-voltage battery charging apparatus comprises a bus contactor interposed between the high-voltage bus and the battery charger, which is bus contactor configured to provide a first substantial electrical isolation between the battery charger and the high-voltage bus during a charging period of the battery module. Furthermore, the high-voltage battery charging apparatus comprises an isolation mechanism interposed between the battery charger and the high-voltage bus and also interposed between battery charger and the battery module, which is configured to provide a second substantial electrical isolation between the battery charger, the battery module, and the high voltage bus during a non-charging period of the battery module.