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BQ76940: Balancing at group boundary

Part Number: BQ76940

Hi,

I have a question respective to design consideration in slua749, section 4, figure 8:

Between each cell is a resistor RconnX placed parallely. The use of these is not clear to me. As the text above the figure states, one group can be balanced while another is measured. "At the cell boundary between groups, the adjacent cell may measure a voltage from the balance current in any common path." 

Are these resistors there to provide a clean measurement while balancing the nearest cell group? But why are they placed at each cell instead just at the borders to each group, e.g. between connection VC5 and VC5B like Rconn5? 

  • The Rcon is not an "active resistor", rather a lumped model to show the added resistance in layout. In brief, this resistance is series with the cell and pin and can add

    unwanted extra voltage and power losses. Suggest minimization of the I*R of the junction of the 3 paths.