The present disclosure relates to a vehicle power system. In some examples, the vehicle power system can include a plurality of redundant low-power buses coupled to respective low-power batteries. The low-power buses can be powered by a vehicle battery having a higher voltage than the voltage of the low-power batteries by way of a DCDC converter, for example. In some examples, the DCDC converter can be coupled to the low-power buses via a plurality of switches included in an Auxiliary Voltage Controller (AVC). The DCDC converter and the AVC can be housed in a common package to reduce the size, weight, and complexity of the power system while also improving the power system's durability.