Lithium battery function test method analysis

Lithium battery is a product that requires high quality and high safety. Customers often don't know the function of the battery when using it. As a result, the working power of the battery is often not up to the aspirational target during use. Sometimes blind use can cause the occurrence of battery blasting incidents. , Life safety will also be compromised, so knowing the function of the battery is also crucial. Lithium battery function test mainly includes voltage, internal resistance, capacity, internal pressure, self-discharge rate, cycle life, sealing function, safety function, storage function, appearance, etc. Others include overcharge, overdischarge, solderability, and corrosion resistance. Sex and so on. Method 1: Self-discharge test The self-discharge test of lithium batteries is generally: 24-hour self-discharge is generally used to quickly test its charge persistence ability. The battery is discharged at 0.2C to 3.0V, and constant current and constant voltage is charged to 4.2V at 1C. Current: 10mA, after 15 minutes, discharge at 1C to 3.0V to measure the discharge capacity C1, then charge the battery with constant current and constant voltage 1C to 4.2V, cut-off current 100mA, and measure 1C capacity C2, C2/C1 after 24 hours ×100% should be greater than 99%. Method 2: Internal resistance measurement. The internal resistance of a lithium battery refers to the resistance encountered by the current flowing through the battery when the battery is working. It is generally divided into communication internal resistance and DC internal resistance, because the internal resistance of the rechargeable battery is very small, and the DC is measured. In the case of internal resistance, since the electrode is easily polarized and the polarization internal resistance occurs, its true value cannot be measured; and the measurement of the communication internal resistance can avoid the influence of the polarization internal resistance and obtain the true internal value. The communication internal resistance test method is: use the characteristics of a lithium battery equivalent to an active resistor, give the battery a constant current of 1000HZ, 50mA, sample its voltage, rectify, and filter a series of solutions, and then accurately measure its resistance. Method 3. Drop test. After being overcharged, the lithium battery pack is dropped from three different directions on a hard rubber plate at a height of 1m. Do this twice in each direction. The battery pack should function normally and the outer packaging should not be damaged. Method 4: After the impact test of the lithium battery is overcharged, a 15.8mm diameter hard rod is placed on the battery, and a 20-pound weight is dropped from a height of 610mm on the hard rod. The battery should not be blasted. Fire or leakage. Method 5: Puncture experiment After the lithium battery is overcharged, use a nail with a diameter of 2.0mm~25mm through the center of the battery and leave the nail in the battery. The battery should not burst into flames. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Under what circumstances can lithium iron phosphate batteries have the upper hand