Patent ID: 8558509

Claim:
A system for preventing battery damage by internal battery abnormalities during charging or discharging states of the battery, comprising: a first circuit for automatically determining when the battery is in a charging state and when the battery is in a discharging state; a second circuit for sampling a voltage of the battery at sequential time points; a third circuit for measuring a decline of the voltage; a fourth circuit for counting T dec , which is a time during which the voltage is in decline, and for counting T rise , which is a time during which the voltage increases after a period of decline, wherein the count of T dec is reset to zero when T rise lasts longer than a preset time delay, and wherein the count of T dec is resumed when the voltage resumes its decline after a period of increase and T rise of the period of increase is shorter than the preset time delay; a fifth circuit for measuring a rate of the decrease of the voltage; and a sixth circuit for producing an indicator of internal battery abnormality under the following conditions: when the battery is in the discharging state and the rate of the decrease of the voltage exceeds a predetermined decline rate; when the battery is in the charging state and T dec exceeds a predetermined time; and when the battery is in the charging state and the decrease of the voltage exceeds a predetermined voltage.