VEHICLE POWER DEVICES, SYSTEMS, AND METHODS FOR FAIL OPERATIONAL ELECTRONIC CONTROL UNIT POWER MANAGEMENT

A power supply device for a vehicle that includes two or more independent power sources, a simple low-power voltage monitor connected to a fast switch device, an electronic control unit (ECU), and a dedicated standby monitor element. Each power source has a separate path to connect to the load(s). That is to say, a primary path connects the primary power source to the one or more loads, and a backup path connects the backup power source to the one or more loads. Furthermore, each path includes a back-to-back blocking element, which prevents a direct connection between the primary power source and the backup power source. At standby, both or all paths are blocked except the standby monitor, ensuring extremely low quiescent current. When the system is ON, the voltage level of the power system is monitored; if the voltage level drops below a threshold level, then the paths are switched.