Do you know Lithium Battery Charging Technology?

We follow the Lithium Iron Phosphate Battery Rack Manufacturer to understand the theoretical basis of lithium battery charging technology: In 1972, the American scientist James proposed that the battery has the best charging curve during charging: I = I0e-αt, where: I0 is the initial charge of the battery Current; α is the charge acceptance rate; t is the charging time. The values of I0 and α are related to the battery type, structure and degree of old and new.

The current research on battery charging methods is mainly based on the best charging curve. As shown in Figure 1, if the charging current exceeds this optimal charging curve, it will not only increase the charging rate but also increase the outgassing of the battery; if it is less than this optimal charging curve, although it will not cause damage to the battery, it will prolong Charging time reduces charging efficiency.

How does a Multifunctional Battery System allow charging? There are many ways to charge lithium batteries, which can be divided into conventional charging and fast charging according to charging efficiency. Among them, the conventional charging methods include constant current charging, constant voltage charging, stage charging, and intermittent charging, while fast charging includes pulse charging and Reflex charging, and finally intelligent charging can be performed.

Lithium Iron Phosphate Battery Rack

1. Constant current charging According to the size of the charging current, constant current charging can be divided into fast charging, standard charging and trickle charging. During the entire charging process, the charging voltage of the power supply or the resistance value connected in series with the battery is generally adjusted to maintain the constant charging current of the battery. This method has the advantage of simple control and is suitable for charging a battery pack in which multiple batteries are connected in series. The disadvantage is that the lithium battery's acceptable charging capacity will gradually decrease as the charging progresses. Excessive charging current in the later stage of charging will cause air bubbles inside the battery and cause damage to the battery. Therefore, constant current charging is often used as a link in stage charging.

2. Constant voltage charging means that the charging voltage remains constant during the entire charging process, and the size of the charging current is automatically adjusted as the state of the battery changes. As charging progresses, the charging current gradually decreases. Compared with constant current charging, the charging process is closer to the optimal charging curve, with simple control and low cost. The disadvantage is that the charging time is longer, and the battery charging current is too large in the early stage of charging, which directly affects the life and quality of the lithium battery. Therefore, the constant voltage charging method is rarely used alone, only when the charging power supply voltage is low and the current is large.

3. Intermittent charging method Lithium battery intermittent charging method includes variable current intermittent charging method and variable voltage intermittent charging method. The variable current intermittent charging method was proposed by Professor Chen Tiemiao of Xiamen University. It is characterized by changing the constant current charging to a limited voltage variable current intermittent charging. The first stage (also the main stage) of the variable current intermittent charging method, first uses a larger current value to charge the battery, then enters the constant voltage charging stage, and charges the battery at a constant voltage until the charging current decreases to the lower limit, and the charging ends. In the main charging stage of the variable current intermittent charging method, under a condition of the limited charging voltage, an intermittent method in which the current is gradually reduced is used to increase the charging current, that is, to speed up the charging process and shorten the charging time. However, this charging mode circuit is relatively complicated and costly. Generally, it is only considered for high-power fast charging.

Do you know its charging technology? We are also a supplier of UPS Lithium-Ion Battery Systems, please contact us if you are interested.