Patent ID: 7279805
Filing Date: 2007-10-09
Classification: H02J

Abstract:
1. A vehicle power supply system comprising: a first battery connected to a generator driven by an engine of a vehicle; a second battery connected to an electric load and having an open circuit voltage lower than that of the first battery; a series regulator connecting the first battery and the second battery; detection means which detect a temperature of the series regulator, an output voltage of the series regulator and a load amount of the electric load; and a control unit which controls an input voltage of the series regulator and the output voltage of the series regulator on the basis of detection values of the detection means, wherein the control unit controls an input upper limit voltage value of the input voltage of the series regulator to change an allowable value of a voltage difference between input and output of the series regulator, and wherein the input upper limit voltage value of the series regulator is calculated by a maximum allowable power of a component part of the series regulator, a detection value of a temperature of the component part, a detection value of the output voltage of the series regulator and a detection value of the load amount of the electric load.