Abstract: An improved portable energy consuming device that uses an external power source to store kinetic energy in the device until a desired level is reached and then the external power source is disconnected from the device to form a portable device and an internal power source is automatically used to maintain the desired kinetic energy level. Thus, the external power source causes at least one device load to reach a desired operating level such as temperature and then, when the device is removed from a base on which it is mounted, the external power source is disconnected and an internal power source is automatically connected to the at least one device load to cause it to just maintain the desired operating level. A control circuit is coupled between the internal power source and its associated internal load to cause only sufficient power to be supplied to the load to maintain the desired operating level.