Are lithium-ion battery pack equalization protection boards good? What is the equalization principle of lithium-ion battery protection boards? Many lithium-ion battery protection board manufacturers mention the equalization function when explaining their products. Lithium-ion battery protection boards, which play a crucial role in battery systems, are increasingly valued as an effective means of extending battery life. Among these, the equalization system of lithium-ion battery protection boards, which plays a key role, has also attracted widespread attention.
Are lithium-ion battery pack equalization protection boards any good?
Currently, there are two main types of balanced multi-series lithium-ion battery systems on the market: traditional passive balancing and active balancing. There is some debate regarding whether lithium-ion battery pack protection boards should include balancing functionality. Below is a perspective from a lithium-ion battery manufacturer.
1. Situations where balancing is necessary: When lithium-ion battery packs are manufactured and stored for a long time, the voltage of each string of batteries in the entire battery pack becomes inconsistent due to the different static power consumption of each circuit of the protection board and the different self-discharge rates of each cell. This results in a significant voltage difference. However, while ensuring consistent capacity, balancing can balance the voltage of the lithium-ion battery pack, thereby achieving the effect of full charging and full discharging of the battery pack and maximizing its performance.
2. The balancing function is not effective: Many people believe that balancing is useful in the middle and later stages of lithium-ion battery pack use. In fact, in the middle and later stages of battery pack use, due to the different capacity loss of each cell, a capacity difference is caused. The balancing function of the protection board cannot make up for the cell capacity. Therefore, we should understand that the lithium-ion battery protection board balances voltage, but cannot make up for the capacity.
For lithium-ion battery packs with 13 or fewer cells, it is recommended to omit the balancing function. However, strict control over battery matching is essential to ensure consistency in cell capacity and internal resistance. Lithium-ion batteries are susceptible to damage during storage, but not during use! Individual lithium-ion batteries are better stored than entire packs. Once a battery pack is assembled, it should be tested and delivered to the consumer as soon as possible.
When charging a series of lithium-ion batteries, it is essential to ensure that each cell is charged evenly; otherwise, the performance and lifespan of the entire battery pack will be affected during use. Commonly used equalization charging techniques include constant shunt resistor equalization charging, on-off shunt resistor equalization charging, uniform battery voltage equalization charging, switched capacitor equalization charging, buck converter equalization charging, and inductor equalization charging.
Lithium-ion battery protection board equalization principle
During the charging process, each lithium-ion battery has an equalization circuit. The equalization circuit of the lithium-ion battery protection board controls the voltage of each battery during charging, so that each string of batteries maintains the same state, ensuring the performance and lifespan of the lithium-ion battery.
The single-cell lithium-ion battery protection chip in the equalization principle control circuit of the lithium-ion battery protection board can be selected based on the voltage level and protection delay time of the single lithium-ion battery to be protected. The shunt discharge branch resistor can be implemented using a power resistor or a resistor network.
The lithium-ion battery protection board's equalization principle protection chip subsystem model primarily uses logic operation modules, symbolic function modules, one-dimensional lookup table modules, integration modules, delay modules, switching modules, and mathematical operation modules to simulate the timing and logic of protection actions. Because the simulation environment differs somewhat from the actual circuit, filtering and strong/weak current isolation should be avoided during simulation, and unnecessary modules can easily lead to lengthy simulation times.
The equalization principle of lithium-ion battery protection boards, based on the requirements of use, can achieve protection and equalization of power lithium-ion battery packs of any structure and voltage level by changing the protection chip model and series connection number, and the power level of switching devices and energy-consuming components in the circuit.
In summary, lithium-ion battery protection boards protect the battery from overcharging. Balancing functions balance the voltage of the lithium-ion battery pack, enabling it to fully charge and discharge, maximizing the pack's efficiency.
