To provide a vehicle battery current detection apparatus capable of preventing the delay of timing when engine rotation is raised and stabilizing engine rotation at the time of controlling a load response.

The battery detection apparatus 6 includes a driver 70 for acquiring a power generation rate showing an operation state of a vehicle power generator, a communication controller 72, a shunt resistor 50 for detecting charging/discharging current of the battery, an amplifier 52, a power generation rate transmission part 84 for informing ECU 1 controlling output of an engine loaded on a vehicle of the power generation rate, and a microcomputer 64 setting the power generation rate larger than an actually acquired power generation rate when the battery is judged to be in an electric discharge state.