Analyze the correct charging method for lithium iron phosphate battery packs

The charging method of lithium iron phosphate battery pack is proposed to use CCCV charging method, that is, first constant current and then constant voltage. Constant current proposes 0.3C. Constant voltage proposal 3.65. That is, 0.3C current charge in the constant current process, when the battery voltage reaches 3.65V, use 3.65V voltage constant voltage charge, when the charging current is lower than 0.1C (or 0.05C), stop charging, that is, the battery is already Overflowing. When you charge with a constant voltage power supply, you also need to look at the charging current. It is recommended not to charge with a too high voltage. After adjusting the voltage, ensure that the charging current is below 0.5C, which is good for the battery. Generally, the upper limit voltage of lithium iron phosphate battery charge is 3.7~4V, and the lower limit voltage of discharge is 2~2.5V. Considering the five aspects of discharge capacity, median discharge voltage, charging time, constant current capacity percentage, and safety, constant current and constant voltage are adopted. For lithium iron phosphate battery packs, it is reasonable to set the charging limit voltage at 3.55～3.70V, the recommended value is 3.60～3.65V, and the lower limit voltage of discharge is 2.2V～2.5V. The charger of the lithium iron phosphate battery pack is different from the general lithium battery. The highest termination charging voltage for lithium batteries is 4.2 volts; the lithium iron phosphate battery pack is 3.65 volts. When charging the lithium iron phosphate battery pack, it is connected to the balance charging board. Generally, it is charged directly in series from both ends. The voltage of the charger is greater than the voltage of the battery pack. The cable test of the voltage of each single cell is equivalent to connecting a zener tube in parallel. The charging voltage of the single cell will not exceed the voltage stabilization value, while the other single cells are continuously charged and charged through the zener tube bypass. Because the power of each cell is almost overflowing at this time, it is just balancing each cell, so the charging current is small, and each cell is overflowing to complement the balance. The charger can only protect the terminal voltage of the entire battery pack. The balance charging board ensures that each cell is overcharged and each cell is overflowing, and the entire lithium battery pack cannot be stopped because of one battery cell overflowing. 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: What are the key points to pay attention to when mixing lithium battery raw materials?