Performance testing of lithium batteries has made many advancements over the years, leading to many different methods for testing lithium batteries. However, the accuracy and difficulty of these methods vary. So, what are some common lithium battery performance testing methods?
To quickly test the charge retention ability of lithium batteries, self-discharge is commonly used. The usual steps are: first, discharge the battery at 0.2C to 3.0V, then charge it at 1C constant current and constant voltage to 4.2V, with a cut-off current of 10mA. After that, let the lithium battery sit for a period of time, discharge it at 1C to 3.0V to measure the discharge capacity C1, charge the battery at 1C constant current and constant voltage to 4.2V, with a cut-off current of 100mA; finally, test the capacity of the lithium battery after a long period of sitting.
Testing the pressure inside the lithium battery is another method for testing the quality of lithium batteries. We need to simulate the battery at high altitude to check if there are any adverse reactions. The specific steps are as follows: charge the battery at 1C constant current and constant voltage to 4.2V, with a cut-off current of 10mA, then store it for up to 6 hours in a low-pressure box with a pressure of 11.6Kpa and a temperature of (20±3℃). If the battery does not have adverse reactions like explosion, fire, cracking, or liquid leakage, then it passes the test.
The cycle life testing method is used to test the capacity of lithium ion batteries from full capacity to a certain low percentage of capacity, and lithium ion test to see how many charge and discharge cycles they can endure. The specific steps are as follows:
1. The lithium ion battery should be discharged at a constant current of 0.2C to the specified termination voltage (generally 3.0V) at a temperature of (20±5)℃, and then charged at a constant current of 0.2C to the termination voltage (generally 4.2V) and then transferred to constant voltage charging (with a termination current of 0.02C).
2. The lithium battery should be discharged at a constant current of 0.2C to the specified termination voltage at a temperature of (20±5)℃.
3. The lithium ion battery should be cycled at a temperature of (20±5)℃, with no more than 1 hour of rest between charging and discharging or discharging and charging.
4. The lithium battery should be cycled through steps 1 and 2 until the discharge capacity drops below 70% of the rated capacity.
Self-discharge testing, internal pressure testing, and cycle life testing are some of the more common lithium battery performance testing methods. However, reading about these testing methods alone will not provide a complete understanding of the entire process. To fully understand lithium battery performance testing, it is necessary to not only understand some ongoing reliability test methods, but also have powerful testing equipment such as the battery testing system developed by Ourui Technology, which can be viewed in detail.