How to measure the performance of lithium-ion batteries

　　Author ：Iflowpower – Portable Power Station Supplier

First, charge and discharge rate:, the higher, the better C is a dedicated symbol that describes the battery charge current size. 1c discharge represents the battery from full of electricity to an empty current size within 1 hour. The iPhone6 ​​battery capacity is 1810mAh, then the battery's 1C discharge current is 1.

81 amps; each battery capacity used in BYD E6 electric vehicles is 200AH, and the battery 1C discharge current is 200 amps. A battery is discharged with high magnification, and the energy that is usually discharged is less than the low level. Second, the number of charge and discharge cycles:, more than 500 times is the common value of lithium-ion batteries, basis The number of lithium ion batteries made from different materials from 300-3000 times.

The detailed meaning of this value may be slightly different, which can be roughly understood as: according to the charge and discharge rate specified by the manufacturer (such as 1C discharge, 0.3C charge; charge by 0% to 100% each time, this cycle) After 500 cycles, the battery capacity was originally 80%. The relationship between charge and discharge and use habits is too big, we will take a few examples.

1. The influence of charge and discharge intensity on the number of cycles is marked: each time it is charged to 100%, 1c put, 0.3C charge, 500 capacity attenuation to 80%, this is the most stringent detection cycle, also Can not be so strict, see if the loop of each electricity is 25% -75%, 1c put, 0.

3C charge, 2000 capacity attenuation to 80%, if the cycle of each power is 50% -100%, 1c put, 0.3 charge, 1800 capacity attenuation to 80% 2, shallow charge-free lying on life affects factory label: 1C, 1C, 0.3C charge, 500 times after 500 times To 80%, it is the most stringent detection cycle, or it can not be so strict.

Look at the loop of each power below 25% -75%, 1C, 0.3C charge, 2000 capacity attenuation to 80% each time The circulation of the electricity is 50% -100%, 1c, 0.3, 1800, capacity attenuation to more than 80%, two examples can be seen that the magnification of the charging is smaller, the more contribute to the life, and the shallow charge is also Good life.

Third, internal resistance:, the smaller, this parameter varies with load, temperature and other factors change, with the battery life, internal resistance is gradually increased. The smaller the internal resistance, the more high-magnification charge and discharge, the general battery of 18650 is about 50m, and the power type 18650 battery is about 15m. Want to know more about the internal resistance to measure the dedicated equipment, the general us do not work.

Fourth, battery consistency uses the same material, the same process, the battery, the higher the consistency, the better, the better the consistency on the charge and discharge curve. This is very important to make a large-scale component of the battery pack, the greater the size of the battery pack, the higher the consistency requirements.