People use C Rate to define a discharge rate. Most Lipo batteries will say on its description something like “10C to 20C”. This means that 10C is the nominal discharge rate and 20C is the maximum discharge rate.
It’s common to use mah to define battery capacity. A battery with a 2000 mAh capacity can deliver 2 Ampere ( usually short for 2000 mA/2A, 2A=2000 ma) for 1 hour. to make it more clear, it can also send power in 200 mA for 10 hours. The battery capacity, together with the LiPo battery’s discharge rate will define its maximum current output (Ampere, A).
A 3S 2000 maH 10C LiPo pack will get you this: 2000 mAh x 10C = 20.000 mAh discharge rate 20.000 mAh / 1000 = 20 A constant discharge rate.So if your projects requires constant discharging rate higher then 20A, you will need to choose another battery pack, always check with the motor description or product description when you select the battery cells.