Aspects of an efficient, wide voltage range, power converter system are described. In one example, a power converter system includes a first power converter, a second power converter, and a controller for the power converter. An input of the first power converter and an input of the second power converter are connected in series across an input voltage for the power converter system, and an output of the first power converter and an output of the second power converter are connected in parallel at an output of the power converter system. The controller is configured to regulate the second power converter and to determine whether or not to regulate the first power converter based on the input voltage for the power converter system and an output voltage of the power converter system, among other factors, for greater efficiency of the power converter system over wider input and output voltage ranges.