I am looking for circuits used to measure or monitor the current charging of a battery (Li-Ion or NiMH), microchip has proposed the circuit of the following link
ww1.microchip.com/downloads/en/DeviceDoc/51641a.pdf
My concerne is about the circuit given in page 16/30 composed of C12, C15 R16 and R18, how does this circuit work to measure the charging current of the battery and What is the contribution of R16, C12 and R18