Patent ID: 8421416
Filing Date: 2013-04-16
Classification: H02J

Abstract:
1. A compensation circuit for a battery charger for charging a battery having one or more cells which are series connected to an output thereof and have a protective device and current sensing device in series with the battery, the compensation circuit comprising: a first circuit coupled across the protective device for measuring a voltage drop across the protective device; a second circuit coupled to the current sensing device for generating a voltage corresponding to current flow in the battery; an impedance tracking circuit coupled across at least one cell of the battery and generating a signal corresponding to a voltage drop across an internal impedance of the at least one cell of the battery during battery charging, wherein the impedance tracking circuit retrieves a previously computed impedance of the battery cells and calculates a voltage drop across the battery as a product of the internal impedance and the current flow in the battery; and a third circuit coupled to an output of the first, second and impedance tracking circuits for generating a compensation signal for the battery charger at an output thereof, for increasing output voltage of the battery charger so as to charge a battery independent of static impedances and a variable impedance of the battery.