Patent ID: 7598701

Claim:
A battery pack for use in electronic equipment, comprising: a battery block; a charge/discharge circuit which provides a charge/discharge path for the battery block; a non-volatile memory readable and writable by the battery pack; a voltage measurement circuit which measures an output voltage of the battery block; a processor which stops a power supply through the charge/discharge circuit when the output voltage is less than an extinction voltage, resets and stops operating when the output voltage is at and below a reset voltage that is less than the extinction voltage, stores the output voltage measurement in the non-volatile memory on a regular cycle when the output voltage of the battery block is less than the extinction voltage and greater than the reset voltage, and permanently disables functions of the charge/discharge circuit after the processor resets if an amount of change in the output voltage measurement stored in the non-volatile memory per unit time exceeds a predetermined voltage change value.