Calculation of charging time and discharging time of 18650 lithium battery

The charging process of lithium batteries can be divided into four stages: trickle charging (low-voltage pre-charging), constant current charging, constant voltage charging and charging stop. The basic requirement of a lithium battery charger is a specific charging current and voltage, and then to ensure the safe charging of the battery. The purpose of adding other charging auxiliary functions is to improve the battery life and simplify the operation of the charger, including over-discharged battery charging, battery voltage detection input current limit, and partial discharge of the battery after charging after the charger is turned off. The first stage: trickle charge. Trickle charge is used to pre-charge (recycle charge) fully discharged battery cells. When the battery voltage is lower than about 3V, trickle charging is used. The trickle charging current is one-tenth of the constant charging current, that is, 0.1c (taking a stable charging current of 1A as an example, and a trickle charging current of 100mA). The second stage: constant current charging. When the battery voltage is higher than the trickle charging threshold, the charging current of constant current charging increases. The constant current charging current is between 0.2c and 1.0c. The battery voltage gradually increases with the constant current charging process. In general, the voltage of a single battery is set to 3.0-4.2v. The third stage: constant voltage charging. When the battery voltage rises to 4.2v, the constant current charging is completed and the constant voltage charging stage begins. According to the fullness of the battery, as the charging process continues, the charging current gradually decreases from the maximum value. When the temperature drops to 0.01°C, it is considered that the charging has stopped. (C is a way to display the nominal capacity of the battery to the current. If the battery capacity is 1000mAh, then 1C is the charging current of 1000mA.) Phase 4: Charging stop-There are two typical charging stops: a minimum charging current check Or a timer (possibly a combination of the two). The minimum current method monitors the charging current in the constant voltage charging stage, and stops charging when the charging current drops to 0.02~0.07c. The second method starts from the constant voltage charging stage and stops charging after 2 hours of continuous charging. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.