1. Self discharge test. Generally, 24-hour self discharge is used to quickly test its charge retention ability. The battery is discharged at 0.2C to 3.0V, charged at constant current and voltage 1C to 4.2V, with a cut-off current of 10mA. After 15 minutes of storage, the discharge capacity C1 is measured at 1C to 3.0V, and then charged at constant current and voltage 1C to 4.2V, with a cut-off current of 100mA. After 24 hours of storage, the 1C capacity C2, C2/C1 are measured × 100% should be greater than 99%. 2. Internal resistance measurement. The internal resistance of a battery refers to the resistance experienced by the current flowing through the battery during operation. It is generally divided into AC internal resistance and DC internal resistance. Due to the small internal resistance of a rechargeable battery, when measuring the DC internal resistance, the electrode is prone to polarization, resulting in polarization internal resistance, so its true value cannot be measured; Measuring its AC internal resistance can eliminate the influence of polarization internal resistance and obtain the true internal value. The testing method is to use the characteristic that the battery is equivalent to an active resistor, give the battery a constant current of 1000HZ and 50mA, sample its voltage, rectify and filter it, and perform a series of processing to accurately measure its resistance value. 3. IEC standard cycle life testing. According to IEC regulations, the standard cycle life test for lithium batteries is as follows: after discharging at 0.2C to 3.0V/cell, the battery is charged at 1C constant current and voltage to 4.2V, with a cut-off current of 20MA. After being left for 1 hour, the battery is discharged at 0.2C to 3.0V for 500 cycles, and the capacity should be above 60% of the initial capacity. 4. Internal pressure test. The internal pressure test of lithium batteries is to simulate the battery at an altitude of 15240m and check whether the battery is leaking or bulging. Specific steps: Charge the battery 1C with constant current and voltage to 4.2V, cut-off current of 10mA, and then store it in a low-pressure box with a pressure of 11.6Kpa and a temperature of (20 ± 3 ℃) for 6 hours. The battery will not explode, catch fire, crack, or leak
Function of testing report:
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1. Telephone communication and confirmation of requirements
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