Monitoring Discharge Current
Discharge current from a battery is DETERMINED by load, not just "dependent". 

To control the discharge current you need to make a constant-current load, which is usually done with a powerful MOSFET, current-sensing resistor, and a feedback amplifier.

To "monitor" a discharge current, you need to insert a current monitor into discharge loop, usually a small-value shunt resistor connected to a specialized differential amplifier, like INA199 or ZXCT1109.