Patent ID: 8026695

Claim:
Method of operating a battery power management unit in an over-discharge situation, the power management unit being part of a system, comprising a battery and a safety circuit connected to the battery, the method comprising the steps of: charging the battery; detecting an off-state of a device powered by the battery, detecting a state of the power management unit, and determining a state of the safety circuit of the battery, wherein the state of the safety circuit is determined by stopping the charging of the battery while the device is turned off and subsequently loading the battery with a test current to obtain a battery voltage while the device is turned off and comparing the battery voltage to a test voltage while the device is turned off, and wherein an on/off control of the device is made inactive while the safety circuit remains active, wherein the on/off control of the device is maintained inactive such that the device cannot be turned on if the battery voltage is below the test voltage, and wherein the on/off control of the device is made active such that the device can be turned on if the battery voltage is above the test voltage.