What are the common problems with lithium batteries?

1. The voltage is inconsistent, and some are low. Large self-discharge causes low voltage. The self-discharge of the cell is large, and its voltage drops faster than others. Low voltage can be eliminated by checking the voltage after storage. 2. Uneven charging causes low voltage. When the battery is charged after detection, the battery cells are charged unevenly due to inconsistent contact resistance or inconsistent charging currents in the detection cabinet. The measured voltage difference is small during short-term storage (12 hours), but the voltage difference is large during long-term storage. This low voltage has no quality problems and can be solved by charging. Stored for more than 24 hours to measure the voltage after being charged during processing. 2. The internal resistance is too large. If the detection accuracy is not enough or the contact group cannot be eliminated due to the difference of the detection equipment, the internal resistance of the display will be too large. The principle of AC bridge method should be used to test the internal resistance. 2. Long storage time Lithium battery storage is too long, resulting in excessive capacity loss, internal passivation, and large internal resistance, which can be solved by charging and discharging activation. 3. Abnormal heating causes large internal resistance. The battery is being produced abnormally (spot welding, ultrasonic, etc.), causing the diaphragm to heat up, and the internal resistance is seriously increased. 3. Lithium battery expansion 1. Expansion of Lithium Batteries When Lithium Batteries are charged, Lithium batteries will naturally swell, but generally no more than 0.1mm, but overcharging will cause the electrolyte to decompose, increase the internal pressure, and expand the lithium battery. 2. Expansion during production is generally caused by abnormal production (such as short circuit, overheating, etc.) that causes the internal heating to be too large, and the electrolyte decomposes and the lithium battery expands. 3. When the expanded battery is cycled, the thickness will increase as the number of cycles increases, but it will not increase after more than 50 weeks. Generally, the normal increase is 0.3~0.6mm, and the aluminum shell is more serious. This phenomenon It is caused by normal battery reaction. However, if the thickness of the shell is increased or the internal materials are reduced, the expansion phenomenon can be appropriately reduced. 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 post: How to identify the quality of rechargeable batteries?