Patent ID: 8264205

Claim:
A protective circuit for an energy-storage device, comprising: a charge protection circuit adapted to disable current flow into the energy-storage device and allow current to flow out of the energy-storage device while a voltage corresponding to an overcharge state of the energy-storage device is detected; a discharge protection circuit adapted to disable current flow out of the energy-storage device when a voltage corresponding to an overdischarged state of the energy-storage device is detected until a voltage corresponding to an operating range of the energy-storage device is detected and allow current to flow into the energy-storage device while a voltage corresponding to the overdischarged state of the energy-storage device is detected; a first connection terminal configured for direct connection to an external load, a charger, and/or a second energy storage device; a second connection terminal configured for direct connection to the external load, the charger, and/or a third energy storage device; and an anti-parallel diode coupled between and directly connected to the first connection terminal and the second connection terminal.