How to charge a lithium-ion battery

Choosing the appropriate charging method can improve the charging efficiency and prolong the service life. The commonly used charging methods for lithium-ion batteries include constant current charging, constant voltage charging, constant current / constant pressure charging, variable current charging, Pulse charging, and intermittent charging.

1. Constant voltage charging method

The constant voltage charging method refers to charging a lithium-ion battery at a constant voltage during the charging process. In this process, the charged current satisfies the formula: I =(U -- E) / R(I in the formula is the charged current, U is the charged voltage, E is the battery voltage, and R is the charging circuit resistor).

In the initial stage of charging, due to the relatively low battery potential, the charging current is relatively large. As the charging process progresses, the battery potential gradually increases and the charging current gradually decreases. The constant voltage control system has a simple structure, and the charging current is relatively close to the acceptable charging current, which has a certain degree of adaptability. However, the current is relatively large at the initial stage of charging, which may cause the battery temperature to rise too fast and adversely affect the battery.

2. Constant current charging method

The constant current charging method refers to charging with a constant constant current throughout the charging process. The charging acceptable current of lithium-ion batteries decreases exponentially with the charging time, and the charging current remains unchanged. If the charging current is large, the charging current may exceed the acceptable current during the charging period of the constant current, causing the battery electrolyte to undergo a gas precipitation reaction. However, if the charging current is too small, it will prolong the charging time and reduce the charging efficiency.

Both of these methods are relatively simple and have many shortcomings. The initial current of constant voltage charging is too large and the current of constant current charging is too large. Therefore, the charging method of constant current after constant pressure can be used to overcome the disadvantages of these two methods in these two stages.

The page contains the contents of the machine translation.