The capacity of the battery is divided into rated capacity and actual capacity. The rated capacity of the battery refers to the design and manufacture of the battery to stipulate or ensure that the battery under certain discharge conditions, should release the minimum amount of electricity. IEC standards specify the rated capacity of nickel-cadmium and nickel-metal hydride batteries at 20℃±5℃, charging at 0.1C for 16 hours and discharging at 0.2C to 1.0V. For lithium-ion batteries, it is stipulated that they should be charged for 3 h at room temperature, constant current (1C) -- constant voltage (4.2V) under the control of charging conditions, and then the rated capacity of the battery discharged from 0.2C to 2.75V, while the actual capacity of the battery refers to the actual power released by the battery under certain discharge conditions. It is mainly affected by discharge rate and temperature (so strictly speaking, the battery capacity should specify the charging and discharging conditions). The unit of battery capacity is Ah,mAh(1Ah=1000mAh).