The multicell application example from the datasheet is included below:
Deciding the resistor value in the resistor divider depends on the number of cells connected in series. For example, for 3 cells in series, the corresponding value of n is 3. Setting resistor R, the one that is connected to ground to be 1M ohms, the other voltage divider resistor would be (3-1)(3-1)*1M=2M ohms. The current sensor resistor size depends on the largest charge and discharge current. The current sense resistor value is obtained by dividing the full scale of 51.2mV by the largest current. It is also important to take into consideration of the power consumption of the resistor itself. i.e The chosen resistor's rated maximum power consumption should be larger than the power consumption of the resistor under max current conditions. Precision should be 1% or higher but the higher the precision, the better.