A vehicle power supply system has a first battery connected to a generator, a second battery connected to an electric load and a series regulator between the first battery and the second battery. Herein, additional encoding is performed on mobile service data, which are then transmitted, thereby providing robustness in the processed mobile service data, so that the mobile service data can respond more strongly against fast and frequent channel changes. 9% by weight of a melt-spinnable PAN and about 0.