Patent ID: 8058847

Claim:
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 of 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 capacitor for storing a charge of at least one of the cells wherein said capacitor includes a pair of terminals; a first bus switch electrically connected and positioned between said first bus and said capacitor for connecting at least one of the cells to said capacitor; a second bus switch electrically connected and positioned between said second bus and said capacitor for connecting at least one of the cells to said capacitor; a ground switch connected at one terminal to one of the terminals of the capacitor and at an other terminal to ground, said ground switch being configured to move between an open and a closed state under the control of a controller; and a first dedicated bus ground switch electrically connected between said first bus and ground, the first dedicated bus ground switch configured to reduce charge on the first bus independent of charge on the capacitor, and a second dedicated bus ground switch electrically connected between said second bus and ground, the second dedicated bus ground switch configured to reduce charge on the second bus independent of charge on the capacitor.