Lithium ion battery voltage, capacity, the test steps

Source: 2020 - 04 - 12 20:53 hits: lithium-ion battery voltage, capacity, internal resistance and pulse test program in order to further understand the characteristics of lithium ion battery, this article selects the lithium iron phosphate batteries a series of experiments. Lithium iron phosphate batteries at present is considered to be the best lithium ion battery performance, wide range of applications. The experiment USES 3. 2 v / 12。 5 ah single lithium ion battery, specific parameters are shown in table 1. This type of lithium iron phosphate batteries to power battery, it is mainly used for power tools and energy storage power field. Because it can be used in the complex working conditions, is a representative of the lithium ion battery. Table 1 the name of the conventional battery indicator specifications battery power lithium ion battery rated capacity of 12. 5 o rated voltage 3. The weight of 353 g + / - 2 v 0. 5 v 2 c (maximum charging current Continuous) 4C ( 10s) Charging voltage: 3. 65v± 0. 5 v maximum discharge current 4 c ( Continuous) 6C ( 30s) Discharging termination voltage 2. 0 ~ 0 v charging temperature 45 ℃ - exhaust temperature 20 ~ 60℃; The characteristics of the composition of the lithium ion battery testing system is based on the battery test platform. Is the main purpose of the battery test on the battery performance have a more comprehensive understanding and quantification, establish data support to the research of battery characteristics and theoretical basis. Battery test platform is shown in figure 2. The use of equipment are: lithium iron phosphate batteries, Digatron automatic charging and discharging test devices and PC. Digatron automatic charging and discharging test equipment to the battery state of charge and discharge test. PC communicate with Digatron automatic charging and discharging test devices, set up the working state of the equipment, recording time, voltage, current, such as data, process and analysis of the collected data. In this paper, all the battery test are conducted at room temperature. Figure 2 battery test platform figure 2 battery test platform, in the process of charging and discharging the battery working electrical current charge and discharge ratios for commonly used, it is equal to the rated capacity battery on numerical multiples. Make sure the battery fully charged, charging system stipulated as follows: first rechargeable batteries constant current ( 1/3c) 3. In constant voltage 65 v, and then charge for 3. 65 v, until the current is less than 0. 033 degrees, and then in 10 minutes to stop charging, it stands for 1 h. In this paper, design of battery experiment with reference to the national industry standard QC/t743 - 2006 [ 5] 。 Specific experimental content is as follows: ability tests under different discharge rate in order to measure the actual capacity of li-ion battery, the control for testing the discharge rate of I = { 0. 2C,0. 5 c, 1。 0 c, 1。 5 c, 2。 0 c} 。 Each test shall be carried out in accordance with the following five steps: first step: to recharge the battery in the second step: stand for an hour in the third step: to I discharge for discharge rate. When the battery voltage to 2. Step 4:0 v to stop discharge stand for an hour at the end of the test, with 0. 02 c small current open circuit voltage characteristic test of the battery will be put to test the lithium ion battery in the discharge process and the residual capacity of different electromotive force in the process of charging, the test is divided into the discharge process and charging process. Discharge process test according to the following steps: first step: to recharge the battery in the second step: stand for an hour in step 3. In a third c constant discharge rate discharge 18 minutes; The battery voltage is lower than 2 within 18 minutes. 0 v, enter step 5; Otherwise, in step 4. Step 4. Let it rest for an hour, and then go back to step 3 at the end of the test, with 0. 02 c small current will release the electric charge in the battery test process is as follows: the first step: the second step: empty battery stand for an hour in step 3. For a third c discharge rate, 18 minutes continuous discharge the battery. If the battery voltage in the 18th min is higher than 3. Step 5 to 6 v,; Otherwise, in step 4. Step 4. Let it rest for an hour, and then go back to the third step 5. After the test, to recharge the battery