What are the charging and discharging requirements for Fe-Li-ion battery packs?
Charging and discharging requirements of iron lithium ion battery pack 1. Charging of lithium ion battery pack: According to the structural characteristics of lithium ion battery pack, the highest charge termination voltage should be 4.2V, and it cannot be overcharged, otherwise it will take too much lithium ion from the positive electrode. More, and the battery is scrapped. The charging and discharging requirements are relatively high, and a dedicated constant current and constant voltage charger can be used for charging. Normally, the constant current charge to 4.2V/cell and then the constant voltage charge. When the constant voltage charge current drops to less than 100mA, the charging should be stopped. Charging current (mA)u003d0.1～1.5 times battery capacity (such as 1350mAh battery, its charging current can be controlled between 135～2025mA). The normal charging current can be selected at about 0.5 times the battery capacity, and the charging time is about 2 to 3 hours. 2. Discharge of lithium-ion battery: due to the internal structure of the iron-lithium-ion battery pack, all lithium ions cannot move to the positive electrode during discharge, and some lithium ions must be retained in the negative electrode to ensure that lithium ions can be inserted smoothly during the next charge. aisle. Otherwise, the battery life will be shortened accordingly. In order to ensure that some lithium ions remain in the graphite layer after discharge, it is necessary to strictly limit the minimum discharge termination voltage, which means that the lithium ion battery cannot be over-discharged. Lithium-ion battery pack chargers require charging voltage and charging current. Li-ion battery chargers are specially designed to charge lithium-ion batteries. Lithium-ion batteries have higher requirements for chargers and need to protect circuits. Therefore, lithium-ion battery chargers usually have higher control precision and can charge lithium-ion batteries at a constant current and voltage. The basic requirement of a lithium-ion battery pack charger is a specific charging current and charging voltage, so as to ensure the safe charging of the battery. Other charging auxiliary functions are added to improve battery life and simplify the operation of the charger, including trickle charging for over-discharged batteries, battery voltage test, input current limit, turn off the charger after charging is complete, and after the battery is partially discharged Automatically start charging, etc. The charging method of the lithium iron phosphate battery pack is voltage-limiting and constant-current, which is controlled by the IC chip. The typical charging method is: first test the voltage of the battery to be charged, if the voltage is lower than 3V, pre-charge and charge The current is 1/10 of the set current, and after the voltage rises to 3V, it enters the standard charging process. The standard charging process is: constant current charging with the set current, when the battery voltage rises to 4.20V, change to constant voltage charging, and keep the charging voltage at 4.20V. At this time, the charging current gradually decreases, and when the current drops to 1/10 of the set charging current, charging ends.