components when opened and connect the vehicle traction battery 24 to other components when closed the power electronics module 26 is also electrically connected to the electric machines 14 and provides the ability to bi directionally transfer energy between the vehicle traction battery 24 and the electric machines 14 for example a typical vehicle traction battery 24 may provide a dc voltage while the electric machines 14 may require a three phase ac current to function the power electronics module 26 may convert the dc voltage to a three phase ac current as required by the electric machines 14 in a regenerative mode the power electronics module 26 may convert the three phase ac current from the electric machines 14 acting as generators to the dc voltage required by the vehicle traction battery 24 the description herein is equally applicable to a pure electric vehicle for a pure electric vehicle the hybrid transmission 16 may be a gear box connected to an electric machine 14 and the engine 18 may not be present in addition to providing energy for propulsion the vehicle traction battery 24 may provide energy for other vehicle electrical systems a typical system may include a dc dc converter module 28 that converts the high voltage dc output of the vehicle traction battery 24 to a low voltage dc supply that is compatible with other vehicle loads other high voltage loads such as compressors and electric heaters may be connected directly to the high voltage without the use of a dc dc converter module 28 the low voltage systems may be electrically connected to an auxiliary battery 30 e g 12v battery the vehicle 12 may be any vehicle with.