"input impedance of 1K5 " just means your meter draws a lot of current - in this 7.4V/1500 = 5mA, could use 4.7K.10K and cut that down to 0.5mA.
7.4 to 470, to 1K to gnd. Junction of 470/1K should be 5.03V if batteries were discharged and down at 3.7V. (7.4*1K)/(.47K + 1K)
Fresh batteries will be more like 8.4V tho, so 5.71V, dropping to ~5V when discharged.
Consider changing your R values to reflect that.