Patent ID: 8054045

Claim:
A status detector used for a power supply which provides electricity accumulating means and measuring means for measuring at least current, voltage, and temperature of the electricity accumulating means, comprising: memory means for storing characteristic information of said electricity accumulating means; and processing means for executing calculation for detecting state of charge of said electricity accumulating means by using information including the measured information obtained from the output of the measuring means and the characteristic information which is stored in said memory means; wherein said processing means comprises: a first state of charge detecting means for obtaining a first state of charge of said electricity accumulating means by using information including an open circuit voltage of said electricity accumulating means, and said open circuit voltage is obtained by using information including the measured information and the characteristic information; a second state of charge detecting means for obtaining a second state of charge of said electricity accumulating means by using information including the current information of said electricity accumulating means obtained from the output of said measuring means; an error detecting means for obtaining a product of a current of said electricity accumulating means obtained from the output of said measuring means, and an internal DC resistance of said electricity accumulating means; weight deciding means for obtaining first and second weights which weight to said first state of charge and said second state of charge by using the product of the current and the internal DC resistance obtained by said error detecting means; and means for obtaining the state of charge of said electricity accumulating means by combining a state of charge which is obtained by weighting the first weight to said first state of charge and a state of charge which is obtained by weighting the second weight to said second state of charge.