A power management system for a mobile electronic device, including a microprocessor for continually monitoring a voltage of a battery within a mobile electronic device, wherein the device can operate in either a standalone mode powered by the battery, or in an externally powered mode, and wherein the battery is charged when the device is in external power mode, and a power manager coupled with said voltage meter, for controlling operation of the device according to the following logic: if the monitored voltage falls below an upper turn-on threshold, UTOT, during operation of the device in standalone mode, but is above a lower turn-on threshold, LTOT, then automatically turning the device off, and enabling the device to be turned on in an emergency mode, wherein at least one emergency action is enabled, and if the monitored voltage falls below LTOT during operation of the device in standalone mode, then automatically turning the device off, and preventing the device from being turned on. A method is also described and claimed.