Patent ID: 8258756

Claim:
A current breaking method of rechargeable battery, the method comprising: (a) measuring a current value when a current flows through a high current path of a rechargeable battery; (b) measuring a duration time of the current flowing through the high current path; (c) setting a permission time for which the current is permitted to flow according to a magnitude of the measured current value; and (d) interrupting the current flowing through the high current path when the duration time of the current exceeds the permission time, wherein the permission time is determined according to a first function defined as: Y=a *exp (b*t) where Y is the current value, a and b are constants, t is the permission time, and exp is an exponential function, or wherein the permission time is determined according to an n-th degree equation defined as: Y=a*t n +bt n−1 . . . +c where Y is the current value, a, b and c are constants, and t is the permission time, n is a degree.