Abstract: This system provides a method for determining whether ordinary battery cells, a battery pack, and/or a charger unit are attached to a portable electronic device. The system provides a center contact in a battery shaft that contacts a battery pack or a point on an individual battery and allows the device regulation unit to measure the voltage at that point. If the voltage is below a particular threshold, then the system determines that a battery pack may be inserted in the battery shaft and the portable electronic unit enters a battery pack mode. If the voltage is above the threshold voltage, then the portable electronic device enters the battery operation mode. If a voltage transition is sensed on the DEVICE START line, the portable electronic device determines that the charger is installed and the portable electronic device enters the appropriate mode.

Abstract: This system provides a method for determining whether ordinary battery cells, a battery pack, and/or a charger unit are attached to a portable electronic device. The system provides a center contact in a battery shaft that contacts a battery pack or a point on an individual battery and allows the device regulation unit to measure the voltage at that point. If the voltage is below a particular threshold, then the system determines that a battery pack may be inserted in the battery shaft and the portable electronic unit enters a battery pack mode. If the voltage is above the threshold voltage, then the portable electronic device enters the battery operation mode. If a voltage transition is sensed on the DEVICE START line, the portable electronic device determines that the charger is installed and the portable electronic device enters the appropriate mode.