Li-ion battery charging principle: the selection method of charging voltage and current

Li-ion battery charging principle: the selection method of charging voltage and current 1. What is the best current for charging a lithium-ion battery? A lithium-ion battery must be charged with a constant current first, that is, the current must be charged, and the battery voltage and the charging process gradually increase, when the battery The voltage is 4.2V, reaching 4.1V), constant voltage charging, not the voltage must be current and constant current charging based on the full range of the battery, according to the charging process is continuously reduced, when it is reduced to 0.01 degrees Celsius, the charging is considered to be suspended. (C is a method of indicating the rated capacity of the battery based on the current. For example, if the battery capacity is 1000mAh, then 1C is the charging current 1000mA. Note that this is mA instead of Ah. Why do you think that 0.01C is the end point of charging: This is the country The provisions of the standard GB/t18287-2000 are also comments. In the past, what we completed was 20mA. The industry standard YD/t998-1999 of the Ministry of Posts and Telecommunications is the same rule, that is, no matter how large the battery capacity is, the stop current is 20mA. The national standard stipulates 0.01C helps to charge more fully, which is an advantage after confirmation by the manufacturer. In addition, the national standard stipulates that the charging time should not exceed 8 hours, that is, even if it does not reach 0.01C, it is considered that the charging has been completed for 8 hours. (There is no problem with the quality of the battery. It should reach 0.01 degrees Celsius within 8 hours. It is not a good quality battery, and it is meaningless to wait) The best charge rate of lithium ion or lithium polymer battery is 1C, which means a 1000 mAh battery with a fast charging current of 1000 mAh Yes, at this rate, the charge can be completed in the shortest time without reducing battery performance and shortening the service life. Regarding the battery pack with increasing capacity, in order to achieve this satisfactory charging rate, the increase in the charging current value is inevitable 2. What is the best voltage for charging lithium-ion batteries? The nominal voltage of lithium-ion batteries is 3.7v (3.6v), and the charging cut-off voltage is 4.2v (4.1v, according to the battery brand, there are different designs). How to distinguish the battery is 4.1 v or 4.2v: Consumers can’t distinguish, it depends on the battery manufacturer’s product specifications. Some brands of batteries are 4.1v and 4.2v in general, such as Au0026TB (Toshiba), domestic manufacturers are basically 4.2v. If you put What happens when a 4.1v battery is charged to 4.2v: It will increase the battery capacity and it is very convenient to use. Assume from 500 to 300. Similarly, if the 4.2v battery is overcharged, the life will be shortened. Lithium-ion battery Very fragile. If the battery already has a protective plate, can we stabilize it? No, because the cut-off parameter of the protective plate is 4.35v (still possible, but the difference is 4.4v and 4.5v), so the protective plate is required For intermediate frequency. If the battery is overcharged every time, the battery will age quickly. 3. What is the battery capacity of Apple iPhone? The battery specification of Apple iPhone is 3.7v nominal voltage, 4.2v charging cut-off voltage, and battery capacity 1400mAh According to the above, the optimal charging rate is 1C. The current required to reach 1400mA to start charging, the voltage is 3.7v. 4. What is the voltage and current of the usb interface and charger? The usb interface current is 500mA, and the voltage is + 5V. If you turn on HWinfo during charging, you can also see the external power supply. The 500mA charger is designed for iPhone. In summary, when using USB to charge, the voltage is +5V and the current is only 500mA. We understand the answers to question 1 and question 2, This method will increase the battery capacity, which is very cool to use, but will reduce the battery life. When using a charger to charge, we may ask, didn’t you say that the best speed is 1C? It is correct to think that the iPhone should be charged with 1400mA charging current, yes, but the country also has regulations. The low charging rate specified by gb is 0.2 c (regulated charging system), also take the 1400mAh capacity battery of the iPhone as an example, which is 280mA. In theory, the smaller the battery is, the more beneficial it is. But you can't wait three days for a battery charge. (Capacity mAhu003dCurrent mA×Time h) So Apple chose 0.7c. Most batteries are between 0.5c and 0.8c. You can choose 5! Obviously, some people use USB to charge, which feels longer, but this is Dedicated battery life value statement: Some pictures and content of articles published on this site are from the Internet, if there is any infringement, please contact to delete