Patent ID: 7649340
Filing Date: 2010-01-19
Classification: H01M,H02H,H02J,Y02E

Abstract:
1. A battery pack having a secondary battery therein, comprising: one or more voltage converters; a discharge control FET to permit or shut off a discharge of said secondary battery in accordance with a first signal which is supplied to a gate terminal of said discharge control FET; a charge control FET to permit or shutoff a charge of said secondary battery in accordance with a second signal which is supplied to a gate terminal of said charge control FET; a protecting circuit to permit output of the first signal that permits the discharge to said gate terminal of said discharge control FET when a battery voltage of said secondary battery is equal to or more than a lower limit value in a rated voltage range of said secondary battery or to permit output of the second signal that permits the discharge to said gate terminal of said charge control FET when the voltage of said secondary battery is equal to or less than an upper limit value in the rated voltage range of said secondary battery; an output terminal of said voltage converter connected to at least either the gate terminal of said discharge control FET or the gate terminal of said charge control FET; a first switch for the discharge control FET connected between the output terminal of said voltage converter and the gate terminal of said discharge control FET; a second switch for the charge control FET connected between the output terminal of said voltage converter and the gate terminal of said charge control FET; a first resistor connected between an output terminal of said protecting circuit from which the signal to permit said discharge is outputted and the gate terminal of said discharge control FET; a first diode anode connected to the output terminal of said voltage converter; a first diode cathode connected to one terminal of said first switch for the discharge control FET; a second resistor connected between the output terminal of said protecting circuit from which the signal to permit said charge is outputted and the gate terminal of said charge control FET; a second diode anode connected to the output terminal of said voltage converter; and a second diode cathode connected to one terminal of said second switch for the charge control FET.