Patent ID: 7531986
Filing Date: 2009-05-12
Classification: H01M,H02J,Y02E

Abstract:
1. An auxiliary power supply for use with a battery powered device including first electrical circuitry which presents a time varying electrical load and a first rechargeable battery which provides electrical energy to the first electrical circuitry, the auxiliary power supply comprising: a battery receiving region adapted to receive a second battery; second electrical circuitry, wherein the second electrical circuitry receives a signal from the battery powered device, which signal is indicative of the magnitude of the time varying electrical load, wherein the second electrical circuitry utilizes energy from the second battery to produce a power supply output ( a first electrical connector in operative communication with the second electrical circuitry and adapted to selectively electrically connect the power supply output to the battery powered device: wherein the signal includes a measured value of the time varying electrical load and wherein the measured value of the time varying electrical load includes a measured value of an electrical load current, and wherein the second electrical circuitry adjusts the power supply output current as a function of the first rechargeable battery voltage, the second battery voltage, and the measured value of the time varying electrical load current.