Characteristic of echargeable lithium battery a. Environmental conditions Unless otherwise specified, all tests stated in this specification are conducted at temperature 23±3°and humidity under 65%. b. Measuring equipment (1) Amp-meter and volt-meter The amp-meter and volt-meter should have an accuracy of the grade 0.5mA and mV or higher. Slide caliper The slide caliper should have 0.01 mm scale. (3) Impedance meter The impedance meter with AC 1kHz should be used. c. Standard charge Charging the cell CCCV with charge current 0.5C, constant voltage 4.2V and 100mA cut-off in CV mode at 23℃for capacity. d. Standard discharge capacity Discharge current of 400mA (0.2C) with 2.5V cut-off at 23℃within 1hour after the standard charge.