of data points to average out at least some of the effects of measurement error n is equal to twelve in the embodiment of fig2 n however may vary depending on design etc and may be determined for example via testing simulation etc if no the controllers s 22 determine whether a wait time t2 has passed at operation 32 as explained above time averaging of the voltage measurements seeks to reduce the effects of measurement error the wait time t2 may therefore be selected so as to temporally space out the voltage measurements to maximize the benefits of time averaging in reducing the effects of measurement error a wait time t2 of 30 sec is used in the embodiment of fig2 this wait time however may vary depending on the type of cells 13 design configuration etc and may be determined for example via testing etc if no the controller s 22 return to operation 32 if yes the controller s 22 return to operation 28 returning to operation 30 if yes the controller s 22 determine an average voltage for each of the cells 13 at operation 34 the controllers s 22 for example may sum the voltage measurements for each of the cells 13 and divide the sums by n at operation 36 the controller s 22 determine a cell balancing discharge time for each of the cells 13 based on the voltage measurements determined at operation 30 as discussed below referring to fig1 2 and 3 each of the.