US Patent 7679331 Power control circuits

Power control systems and methods are provided to control when and how power is removed from devices. A power control system includes a sensing module that detects an output voltage level of a battery pack. A shutoff module initiates a shutoff routine when the output voltage level decreases to a device shutoff voltage level. The device shutoff voltage level is greater than the battery pack shutoff voltage level. A bypass module prevents the initiation of the shutoff routine when the device performs one or more operations that are known to cause high battery current spikes that will resultant in significant voltage drops from the battery pack.