C: It is used to indicate the ratio of the battery charge and discharge current, that is, the magnification. Charge/discharge rate=charge/discharge current/rated capacity, such as 1200mAh battery, 0.2C means 240mA (0.2 times of 1200mAh), 1C means 1200mA (1 times of 1200mAh).
RC devices need high rate discharger battery, like 20C, 25C, 30C.
Our battery discharger battery are under 1C. all are low rate discharger batteries.