The charging of lithium battery needs constant current charging. When the battery voltage reaches a certain value, it enters the constant voltage charging mode. Why do we need constant current and constant pressure? In fact, no matter constant pressure or constant current, its principle is to "activate". The constant current charging mode can make the reaction proceed with a stable and large current. As the reaction proceeds to a certain extent, a layer of film will be formed on the surface of the electrode. At this time, the internal resistance will increase, and the polarization of the internal resistance will increase, resulting in the deviation of the potential of the electrode. At this time, it is necessary to enter constant voltage charging. As the charging proceeds further, the reverse electromotive force begins to increase, the total electromotive force of the whole circuit decreases, the circuit current decreases gradually, and the polarization voltage weakens until the precise control of charging terminates.

Lithium battery charging process

The design of lithium battery charger is fully in line with the demand of lithium battery charging. Can constant voltage and current power supply be used instead of lithium battery charger?

Constant voltage and constant current power supply is a kind of switching power supply. The difference between constant voltage and constant current power supply is that there are two kinds of circuits inside the constant voltage and constant current power supply. The output voltage and current can be continuously adjusted from 0 to rated value. The working mode of constant voltage and constant current will automatically switch in practical work. Lithium battery charger is also a constant voltage and current power supply in essence. The output current is constant, does not change with the grid voltage and load, and most of them have circuit to continuously monitor the battery voltage, which can effectively prevent overcharge.

The difference between lithium battery charger and constant voltage and current power supply is that lithium battery charger has the function of monitoring battery voltage, while constant voltage and current power supply can not be monitored. Therefore, if constant voltage and current power supply is selected to charge lithium battery, lithium battery must have a protective board.

It is possible to replace lithium battery charger with constant voltage and constant current power supply to lithium battery. Its main advantage lies in the centralized charging of lithium batteries, such as the unified charging of multiple lithium batteries in series or in parallel, which is convenient, fast and saves time.