Patent ID: 7332913

Claim:
In a system having a plurality of substantially identical rechargeable battery cells arranged in at least one string between a pair of busses, said at least one string having a plurality of serially connected battery cells to form a battery system, a method for determining across which battery cell in one of said at least one string a test instrument is connected, the method comprising the steps of: a) determining the average voltage of a battery cell in said one of said at least one string; b) measuring the voltage from one of said pair of busses to the side of said test instrument closest to the other of said pair of busses; c) setting n=1; d) multiplying the average voltage by (n+0.5) to obtain V HI ; e) multiplying the average voltage by (n−0.5) to obtain V LO ; f) determining whether the measured voltage is between V HI and V LO ; and g) if the measured voltage is not between V HI and V LO , setting n=n+1 and repeating steps d)-f) until it is determined that the measured voltage is between V HI and V LO ; wherein n is an integer, V HI is a calculated variable representing the high end of a voltage range, and V LO is a calculated variable representing the low end of a voltage range; whereby when it is determined that the measured voltage is between V HI and V LO , this indicates that the test instrument is connected across the n th battery cell counting from said one of said pair of busses.