Patent ID: 7626361

Claim:
A lithium battery pack, comprising: a battery set composed of two or more lithium battery cells connected in series; a first protection circuit including a first voltage detect part for detecting voltages of a first stage of the battery set having two or more battery cells of the battery set, and a first signal output part for issuing an output signal when a detect voltage of the two or more battery cells of the first stage detected by the first voltage detect part goes below a given over-discharge judgment voltage value; a second protection circuit including a second voltage detect part for detecting voltages of a second stage of the battery set, different from the first stage, having two or more battery cells, other than the two or more battery cells of the first stage, of the battery set, and a second signal output part for issuing an output signal when a detect voltage of the two or more battery cells of the second stage detected by the second voltage detect part goes below a given over-discharge judgment voltage value; and dead time means connected between the second signal output part of the second protection circuit for issuing an output not responding to a variation in an input signal occurring within a given time.