Patent ID: 9685797
Date: 2017-06-20
CPC Classifications: H02J

Claim:
1. A method for balancing energy stored in a plurality of cells of a battery having a first terminal and a second terminal, the method comprising: identifying a subset of the plurality of cells having a voltage below a preselected threshold; identifying remaining ones of the plurality of cells having a voltage equal to or greater than the preselected threshold repeatedly open and close a primary switch coupled between the first terminal of the battery and a transformer comprising a primary winding and a plurality of secondary windings, wherein each secondary winding is coupled to one of the plurality of cells via a secondary switch of a plurality of secondary switches and a rectifier circuit, wherein the primary winding is coupled between the first terminal and the second terminal of the battery, and wherein the rectifier circuit rectifies a signal received from a corresponding one of the secondary windings; and closing a subset of the plurality of secondary switches coupled to the identified subset of the plurality of cells and opening remaining ones of the plurality of secondary switches coupled to the identified remaining ones of the plurality of cells while the primary switch is being repeatedly opened and closed.