The AONE is an effective power solution proposal for complete one-cell lithium-iron/ lithium polymer battery protection. This device guards the system against temperature/noise variation by integrating high accuracy voltage circuits, and delay circuits. AONE integrates over charge, over discharge, over current, over charge current, and short circuit detections to guarantee charging safety and enhanced battery life span. Furthermore, the lower current consumption also improves the battery operation time. The AONE, which uses fewer and smaller external components, can easily fit into the limited space of a battery package. Intelligent protection mechanism and compact design makes AONE an economical solution for portable devices.