Abstract: A remote smart battery for supplying a cellular telephone comprises a series of electric energy storage cells, a set of supply contacts connected to the storage cells for supplying electric energy from the storage cells to the cellular telephone, a connector having a plurality of female contacts arranged to be respectively connected to the male contacts of an IC card connector already provided on the cellular telephone. The smart battery further comprises a magnetic stripe reading device, an IC card reading device, and a PCMCIA card reading device. Finally, a microcontroller interfaces the cellular telephone with the reading devices. The microcontroller provides the cellular telephone with a supplement of programming to enable use of the cellular telephone for at least one additional function. Use of the cellular telephone for at least one additional function will be authorized in response to information read on a card by the microcontroller through one of the reading devices.