Method one, self-discharge test

The self-discharge test of nickel-cadmium and nickel-metal hydride batteries is: because the standard charge retention test time is too long, a 24-hour self-discharge is generally used to quickly test its charge retention capacity, and the battery is discharged at 0.2C to 1.0V. 1C charge 80 5 minutes, put it aside for 15 minutes, discharge at 1C to 10V, measure its discharge capacity C1, and then charge the battery at 1C for 80 minutes. After putting it aside for 24 hours, measure the 1C capacity C2, C2/C1×100% should be less than 15%

The self-discharge test of lithium battery is: generally use 24-hour self-discharge to quickly test its charge retention capacity, discharge the battery at 0.2C to 3.0V, charge at constant current and constant voltage to 4.2V, cut-off current: 10mA, leave it for 15 Minutes later, discharge the battery at 1C to 3.0V to measure its discharge capacity C1, then charge the battery at constant current and constant voltage 1C to 4.2V, cut-off current of 100mA, and leave it for 24 hours to measure 1C capacity C2, C2/C1×100% should be greater than 99 %.

Method two, internal resistance measurement

The internal resistance of a lithium battery refers to the resistance experienced by the current flowing through the battery when the battery is working. It is generally divided into AC internal resistance and DC internal resistance. Polarization produces polarization internal resistance, so its true value cannot be measured; and the measurement of its AC internal resistance can avoid the influence of polarization internal resistance and obtain the true internal value.

The AC internal resistance test method is: using the characteristics of a lithium battery equivalent to an active resistor, giving the battery a constant current of 1000HZ, 50mA, sampling the voltage, rectifying, and filtering a series of processes to accurately measure its resistance.

Method three, internal pressure test

The internal pressure test of the lithium battery is: (UL standard) simulates the battery at an altitude of 15240m (low pressure 11.6kPa) to check whether the lithium battery leaks or bulges.

Specific steps: Charge the battery with 1C constant current and constant voltage to 4.2V, cut-off current 10mA, and then store it in a low-pressure box with an air pressure of 11.6Kpa and a temperature of (20±3°C) for 6 hours, the battery will not explode , Fire, cracks, leakage.

Method four, impact test

After the lithium battery is fully charged, place a 15.8mm diameter hard rod on the battery and drop a 20-pound object from a height of 610mm on the hard rod. The battery should not explode, catch fire or leak.

Method 5: Lithium battery cycle life detection