Patent ID: 6920341

Claim:
A secondary-battery control circuit comprising: a first path supplying a first load current from one or more secondary batteries connected in series or parallel, to a system, and including a first cutoff switch; a second path supplying a second load current from said one or more secondary batteries to the system, wherein said first cutoff switch is turned off if a voltage of said one or more secondary batteries is lower than a first predetermined voltage, or if the first load current is greater than a predetermined current, thereby cutting off the first load current to the system; a first standard-voltage generating circuit generating a first standard voltage; a secondary-battery voltage detecting circuit detecting the voltage of said one or more secondary batteries; a first comparing circuit comparing said first standard voltage with the voltage of said one or more secondary batteries, to detect whether said one or more secondary batteries are over-discharged; a second standard-voltage generating circuit generating a second standard voltage; a first voltage detecting circuit detecting a voltage corresponding to a current flowing through said one or more secondary batteries while said one or more secondary batteries are being discharged; and a second comparing circuit comparing said second standard voltage with the voltage detected by said first voltage detecting circuit, to detect whether an excess current flows through said one or more secondary batteries, wherein said first cutoff switch is controlled based on outputs of said first comparing circuit and said second comparing circuit.