Patent ID: 6975095

Claim:
A remaining battery capacity computation system comprising a remaining capacity computation apparatus being connected to an electrical equipment unit via a one line communication circuit, in which current flowing in the battery is detected by the connected electrical equipment unit, the detected current is transmitted to the remaining capacity computation apparatus via the communication circuit, the remaining capacity computation apparatus operates on the detected current transmitted via the communication circuit to compute remaining battery capacity, and the computed remaining capacity is transmitted to the connected electrical equipment unit via the communication circuit; the connected electrical equipment unit having a current detection section which detects current flowing in the battery and outputs a detected current signal at a fixed transmission period to the communication circuit to transmit the detected current signal to the remaining capacity computation apparatus, and a remaining capacity receiving section which receives a remaining capacity signal input from the remaining capacity computation apparatus; the remaining capacity computation apparatus having a remaining capacity computation section which operates on the detected current signal input from the connected electrical equipment unit via the communication circuit and computes remaining battery capacity, and a communication processing section which outputs the remaining capacity signal indicating the remaining battery capacity computed by the remaining capacity computation section to the communication circuit with prescribed timing to transmit the remaining capacity signal to the connected electrical equipment unit; and the communication processing section provided in the remaining capacity computation apparatus outputting the remaining capacity signal to the communication circuit, timed after completion of the output of one detected current signal and until commencement of the output of the next detected current signal from the connected electrical equipment unit to the communication circuit, for transmission of the remaining capacity signal to the connected electrical equipment unit.