Patent ID: 7812570

Claim:
A current detection apparatus for a car power source comprising: a car driving battery; a current detection section that detects a charging current and a discharging current of the car driving battery; a level-shift circuit connected to an output-side of the current detection section, the level-shift circuit being configured to shift both charging current and discharging current output signals of the current detection section; and an A/D converter connected to an output-side of the level-shill circuit, wherein the level-shift circuit shifts the current detection section charging current and discharging current output signals to unbalance a maximum discharging current and a maximum charging current to be detected so that a range of the charging current is narrower than a range of the discharging current received by the A/D converter, wherein the level-shift circuit is configured to shift both charging current and discharging current output signals of the current detection section so that a shifted-line of charging/discharging current-to-voltage is parallel to an original line and the shifted-line and the original line have the same slope.