Patent ID: 7049791
Filing Date: 2006-05-23
Classification: H02J

Abstract:
1. An energy balance circuit for a charger to evenly charge a battery set with a first battery and a second battery connected in series, comprising: a first current storage device, whose one end is coupled to the positive output terminal of the battery set; a voltage storage device, which is coupled to the first current storage device in series using one end; a second current storage device, which is coupled to the voltage storage device in series using one end and coupled to the negative output terminal of the battery set using the other end; a first switch, whose one end is coupled between the first current storage device and the voltage storage device and the other end coupled between the first battery and the second battery; and a second switch, whose one end is coupled between the second current storage device and the voltage storage device, and the other end coupled between the first battery and the second battery; wherein the switches are rapidly turned on and off in such a way that the switch corresponding to the battery with a higher terminal voltage is turned on and off at a high frequency so that the energy in the battery with the higher terminal voltage charges the corresponding current storage device and the energy stored in the voltage storage device charges the battery with the lower terminal voltage.