Patent ID: 7157881
Filing Date: 2007-01-02
Classification: H02J

Abstract:
1. A safety device for balancing a plurality of cells or groups of cells connected in series, or in parallel and in series, comprising: a. a controller assembly comprising an analog controller and a digital controller with the plurality of cells or groups of cells connected in series; b. a disconnect circuit, comprising a charge switch and a discharge switch connected in series, engaging the controller assembly and the plurality of cells or groups of cells connected in series; c. a pack sensing circuit comprising a member selected from the group consisting of a means for measuring temperature, a means for measuring current, and a means for measuring cell voltages; and wherein the pack sensing circuit connects to the controller assembly and the plurality of cells or groups of cells connected in series; d. a balancing circuit comprising a shunt resistor connected to a by-pass switch, wherein the balancing circuit connects between the plurality of cells or groups of cells connected in series and engages the controller assembly; and e. computer instructions for instructing the controller assembly within the safety device to control the disconnect circuit and the balancing circuit; and wherein the plurality of cells or groups of cells connected in series are balanced when operating in a charging phase, a discharging phase, a quiescent phase, and a storage phase.