How to test and repair lithium batteries

1) The customer intuitively judges that the battery does not run far, but the capacity is actually reduced (the protection board is not ruled out, and the protection board test method will be specifically analyzed later). At this time, the battery pack should be charged and discharged to test the capacity and determine the battery discharge time. Of course, pay attention to the protection board parameters when setting the charge and discharge voltage and current. The protection board itself is used for overcharge and overdischarge (the protection board test can be bypassed). It is recommended to use a charging and discharging integrated machine for testing the entire set of lithium batteries, which is not only convenient for testing, accurate data, and flexible control of the charging current. How to judge the charge and discharge cut-off voltage? First of all, it is necessary to know what material cells are used in the battery pack, how many strings are in parallel, and how many cells are in each string. Usually the charge cut-off voltage of the ternary battery is 4.2V, and the discharge cut-off voltage is 2.75V; the charge cut-off voltage of the iron-lithium battery is 3.65V, and the discharge cut-off voltage is 2.5V. So how to calculate the battery pack charging cut-off voltage is very simple, just remember a formula: the number of single strings * battery cell charging cut-off voltage and discharge cut-off voltage calculation method is the same. The maximum charge and discharge current is 0.5c, which is half of the nominal capacity. The current can be reduced according to the situation. It is not recommended to exceed 0.5c. (2) When testing a single string battery, the discharge time of the battery pack is shortened. It must be a problem with some cells of the battery pack, but how to judge which cell it is? It is very simple. For each series of battery pack charge and discharge test, it is recommended to use an instrument that can be used for isolation test without unpacking. Judge the capacity and voltage by charging and discharging a single string, determine which string has the problem, and then disassemble the string of batteries and pull out the string of batteries. Dekang Multi-function Lithium Battery Charge and Discharge Capacity Test Sub-Capacity Aging Equalizer DT50W-16, using 16 channels, each channel is an independent operation motherboard, equipped with 5V10A, the battery pack can be isolated and detected without unpacking, simple and easy to operate Get started, the industry is cost-effective, five-star technical command, life-long after-sales service, technology exchange and learning platform. For more product details, you can search for Dekang DT50W on Taobao or Alibaba, follow the Hangzhou Dekang Company's self-operated store, Hangzhou Dekang Headquarters Factory Store, or scan the QR code at the end of the article. (3) Test the battery cell. Disassemble all the problematic series of batteries, test the batteries on a tester, and judge which battery is the instigator by charging and discharging the batteries, and find out the tumor. By judging the capacity and internal resistance, it is basically possible. The verdict is good or bad. Pick out the bad batteries and re-solder the selected batteries. Then according to the reverse order, the single string is charged and discharged equally, the welding is completed, the charge and discharge test of the entire battery pack, the discharge time is judged, the basic repair process is over, the lithium battery pack can be replaced again, and the battery pack is restored to the best state , And you're done. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What is the principle of lithium titanate battery