A method for operating a buck converter as a power source for electronics of a battery system, includes: operating the buck converter in a first mode in which the buck converter provides a first output voltage; receiving a first control signal; and in response to receiving the first control signal, operating the buck converter in a second mode in which the buck converter provides a second output voltage for a System Basis Chip of the battery system. The first output voltage has a first value in a range of a to b, and the second output voltage has a second value in the range of c to d, wherein b is less than c.