Standard Charge Retention Test for Lithium Batteries

The national standard stipulates that the standard charge retention test for lithium batteries : (IEC has no relevant standards) the battery is placed at 0.2C to 3.0/piece. And then charged to 4.2V at a constant current and voltage of 1C, with a cut-off current of 10mA. After storing for 28 days at 20℃±5℃, discharge to 2.75V at 0.2C. Next, calculate the discharge capacity, and compare with the nominal capacity of the battery, it should not be less than 85% of the initial capacity.