Abstract: A power control system for a vehicle is disclosed. The power control system includes a first low voltage power supply, a second low voltage power supply, and an isolation switch. The first and second low voltage power supplies are capable of providing power to a plurality of subsystems. The isolation switch receives inputs from the first and second low voltage power supplies and selectively outputs power from either of the first and second low voltage power supplies to the plurality of subsystems on at least one power rail. The first low voltage power supply can be a 12-volt direct current-to-direct current (DC-DC) converter and the second low voltage power supply can be a rechargeable 12-volt battery. In case of a power failure to either of the DC-DC converter or rechargeable 12-volt battery, the isolation switch can isolate the failed power supply in the power control system and switch connection to the non-failed power supply to provide power to the subsystems.