Patent ID: 7902830
Filing Date: 2011-03-08
Classification: G01R

Abstract:
1. A system for measuring voltage of individual cells in a plurality of cells connected in series, said system comprising: a plurality of cell switches for electrical connection to the plurality of cells wherein each cell switch includes a first side and a second side with said first side of each cell switch electrically connectable to a positive terminal one of the cells; a first bus electrically connected to said second side of every other cell switch; a second bus electrically connected to said second side of each cell switch not connected to said first bus; a first bus positive switch having a first side and a second side wherein said first side is electrically connected to said first bus; a second bus positive switch having a first side and a second side wherein said first side is electrically connected to said second bus; a first bus negative switch having a first side and a second side wherein said first side is electrically connected to said first bus; a second bus negative switch having a first side and a second side wherein said first side is electrically connected to said second bus; a capacitor for storing a charge of at least one of the cells wherein said capacitor includes a positive terminal electrically connected to said second sides of said first bus positive switch and said second bus positive switch and a negative terminal electrically connected to said second sides of said first bus negative switch and said second bus negative switch; and an amplifier for amplifying the charge stored on said capacitor wherein said amplifier includes an inverting input electrically connected to said negative terminal of said capacitor, a non-inverting input electrically connected to said positive terminal of said capacitor, and an output; a ground switch having a first side and a second side wherein said first side is electrically connected to said negative terminal of said capacitor and said second side is electrically connected to ground wherein when the capacitor has a charge stored thereon, the cell switches, bus switches, ground switch and capacitor are configured to provide the charge on the capacitor to the amplifier and then to discharge the capacitor to ground; and a controller for using the output of the amplifier to measure the voltage of individual cells and to detect a disconnected cell or open circuit within the system.