Patent ID: 7408326

Claim:
A system for controlling at least one battery pack comprising: system electronics including a host processor; and at least one battery pack containing a battery; at least one interface for coupling said system electronics to said at least one battery pack, said interface including a mode control signal interface for communicating a mode control signal from said host processor to the respective battery pack wherein said mode control signal interface comprises a single wire interface; each of said at least one battery pack including selector switches for controlling the delivery of power from said battery to said system electronics, wherein each of selector switches has an on state in which the switch is closed and conducts current and an off state in which the switch is open and does not conduct current; said system electronics further including mode control circuitry responsive to control signals from said host control processor for generating said mode control signal, wherein said mode control signal has one of at least three mode control states specified by said host processor control signals and wherein said mode control signal for each of said at least three mode control states is an analog signal having a magnitude within a predetermined range that does not overlap the predetermined range for other mode signal states; said at least one battery pack being operative to establish the on/off states of the selector switches within the respective battery pack in response to receipt of said mode control signal.