First analysis based on the first dimension of the tests. Battery product specifications usually provide basic parameters such as battery capacity, rated voltage, weight and size, energy density (power, volume), etc. In the appendix you will find charge and discharge curves at different rates and charge and discharge curves at different temperatures. .And the life curve at a precise pace. However, it is not enough to only use the information contained in the specifications to fully understand the battery characteristics and achieve comprehensive battery management. So what test items are needed? The BOL test is easy to understand. The first step is of course the BOL (Beginning of Life) test, which is a complete physical examination of the battery in the early stages of its life.
The tests to be carried out mainly include: the heading testacity, mixed pulse power performance test, flow performance test, self-discharge test, etc. Capacity testing requires the use of Static Capacity Testing (SCT) to measure available battery capacity (including energy) at different ambient temperatures. Different companies and standards have differences in SCT testing methods, but the general idea is similar. Example: Fully charge the battery using the method specified by the battery manufacturer at room temperature (25°C), then discharge it to the cut-off voltage (2.5V) at a rate of 1C after have left it completely in the environment under test, and record the capacity released (energy). In real experiments, the test can be repeated three times in a row to take the average value to improve the accuracy. Capacity test Output: relationship table between temperature and capacity (energy). Prenote time T as the X axis and voltage V as the Y axis. The point on the X axis where the 1C discharge ends at different temperatures is the relationship between capacitance and temperature. The ratio between the area formed by each discharge curve and the X and Y axes is the ratio of the energy available at different temperatures. As shown in the figure below: the S zone of the gray part of the available battery energy at -20°C. It can be seen that SOE can express the remaining energy more accurately than SOC, thus evaluating the remaining mileage more accurately.
What properties are mainly tested in the cycle performance test of lithium battery
Take 3C lithium battery as an example:
1. Continuous charging: Fully charged Core 20 battery plus or minus 5C. According to manufacturer regulations, it will not catch fire, explode or leak when charged for 28 dayscutives.
2. Standard vibration test: fully charged battery cell 20 plus or minus 5C, amplitude 0.8MM, 1Hz/min, between 10-55Hz, three mutually perpendicular directions, each axis tested for 90 minutes. No fire, no explosion, no leak.
3. Temperature cycle: Fully charged cells are placed in a battery test box and the cells are subjected to the following cycle tests. A.) 75+2C4 hours B.) 20+5C2 hours C. )-202C2 hours D) 205C2 hours E. ) Repeat A to D 4 times. F) After 5 cycles, store for 7 days before testing.
4. External short circuit: If the fully charged battery core is 20+5C and 55+2C, short circuit with a resistor with a total resistance less than 100 milliohms, it will not will not catch fire or explode. .
5. Free fall: Fully charged 20+5C battery cell, fall from a height of 1 meter onto the concrete floor in anyte which direction to obtain an impact, 3 times in a row, without fire or explosion.
6. Mechanical vibration: fully charged battery cell 20+5C, maximum acceleration 125-175gn, 3 vibrations of the same intensity in 3 mutually perpendicular directions. No fire, no explosion, no leak.
7. High temperature: A fully charged battery core will not catch fire or explode if placed in an environment of 130 + 2 C for 10 minutes!
8. Battery core pressure: 20+5C, Use a force of about 13Kn on two planes to compress the fully charged battery core so that the longitudinal axis of the battery core is parallel to the plane. Once maximum pressure is reached, release it immediately. No fire, no explosion.
9. Low voltage: a fully charged battery cell maintains 20+5C, 11.6Kpa for 6 hours, no fire, no explosion, no de leak. 10. Overload: 20+5C, discharged battery cell is equal to 10V in heavy rain, charging current is equal to lrec, time is 2.13CZ/rec, rec is equal to current constant recommended by the manufacturer for charging. The unit is the Ampere. No fire, no explosion!
11. Forced discharge: 20+5C, the discharged battery core is discharged with a constant current of 1ItA for 90 minutes. No fire, no explosion!
The above standards are common for 3C lithium batteries in different testing environments. Stable current transmission is required during testing, and high-current shrapnel microneedle modules are used to maintain current conduction and signal. Transmission, playing a stable connection role.
Does the lithium battery need to be inspected after being put into the case?
Take 3C lithium battery as an example:
The test of3C lithium battery performance is one of the items that should be carried out in the first test, including service life, rate, high and low temperature discharge, safety testing, etc.
1. Lifespan
The cycle count of a 3C lithium battery reflects the number of times the battery can be repeatedly charged and discharged. Depending on the environment in which 3C lithium batteries are used, the service life can test the battery life at low temperature, normal temperature and high temperature.
2. Rate
In today's busy life, the requirements for fast charging of 3C lithium batteries are also higher and higher. Therefore, the performance of 3C lithium batteries needs to be tested.
3. High and low temperature discharge test
In the high and low temperature test environment, the lithium batterym 3C is charged and discharged once the charge and discharge cycle is complete. the curve and the data are preserved. Compare it with the curve and data at normal temperature to see if it meets what is stated in the specifications.
4. Safety Test
The safety test of 3C lithium batteries includes overcharge, overdischarge, short circuit, dropping, heating, vibration, extrusion, acupuncture, etc. Foreign objects actively damage the battery to test battery safety.
Lithium 3CThe battery test requires significant currents. The maximum overcurrent of the shrapnel microneedle module can reach 50A. The current transmission is very stable in the range of 1-50A and maintains a good connection.
Battery safety performance test report, UN38.3 test
Yes, lithium batteries need to be inspected after being placed in thehousing.
The reasons are as follows:
1. Ensure battery performance: After the lithium battery is placed in the case, due to the reinforcement and sealing of the case, it may impact the internal performance of the battery, such as pressure changes, l insulation effect between the battery and the case, etc. Therefore, it is necessary to check the battery after inserting it into the case to ensure its normal performance.
2. Prevent battery leakage: If there are defects or problems inside the battery, the battery may leak after being inserted into the case. This will not only damage the battery itself, but also may cause environmental pollution and safety hazards. Therefore, the battery should be inspected after being inserted into the case to ensure that there is no risk of leakage inside.
3. Guarantee product quality: Lithium batteries, after being placed in the shell, are usually sold as components of other electronic products, such as mobile phones, laptops, etc. If there is a problem with the battery after it is inserted into the case, it will impact the quality and performance of the entire product. Therefore, inspecting the battery after being placed in the case can ensure the quality and performance of the final product.
For the inspection of lithium batteries after putting them into the case, the following methods can be adopted:
1. Appearance inspection: Check for warping, cracks and other problems. the battery case, as well as the space between the battery and the case. Is the insulation effect normal?
2. Performance test: test the battery using special test instruments pto check whether its voltage, current, capacity and other performance parameters are normal.
3. Pressure Test: Perform a pressure test on the battery after it is installed in the case to ensure that there is no chance of abnormal pressure inside the battery.
In short, for the inspection of lithium batteries after installation in the case, factors such as performance, safety and final product quality of the battery itself should be taken into account. account comprehensively to ensure its normal operation. during use.
Report, UN38.3 is the battery safety performance test report, UN38.3 is used during air transportation and daily normal use and storage. The UN38.3 battery test (battery safety performance test) has become a test report that must be submitted when transporting lithium batteries. She performse also a complete set of safety performance tests on different types of batteries in accordance with various domestic and foreign standards to ensure product quality and safety for each battery manufacturer, comply with various standards and improve the ability to earn foreign exchange through exports.
Steps to apply for UN38.3:
Step 1: Request an application
1. Determine the client information: a.In which city the will product be exported by air? b. Whether customer's product will be shipped alone or packaged with other products
2. Complete the UN38.3 request form
3. .Provide battery specifications
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3. Provide 30 samples
Step 2: Quotation
Determine the test duration and corresponding costs based on the information provided
Step 3: Pay
After the requester confirms the quotation, signz the application form and service agreement and pay the project fee.
Step 4: Testing
The laboratory performs a comprehensive set of tests on the applied product in accordance with relevant testing standards
Step 5: The test is passed and the report is completed
Step 6: The project is completed and the DGM certificate is issued