What are the precautions for lithium-ion battery balancing

October 10, 2020

What are the precautions for lithium-ion battery balancing

 

Precautions for balancing lithium-ion batteries It takes a long time to balance lithium-ion batteries during discharge. Since the discharge speed is related to the resistance of the load resistance, the efficiency of balancing during system operation is low. If you want to balance during the discharge and the balance time is short, you need to connect a power transistor with a small on-resistance. This type of transistor is very common, such as MOSFET or FET.


If you want to quickly equalize during discharge, you must connect a low-resistance resistor in series with the power transistor to reduce the power consumption of the power transistor. Without this current-limiting resistor, the transistor will quickly consume the lithium-ion battery power.


Measuring the voltage of a lithium-ion battery during charging is not accurate and can cause premature lithium-ion battery equalization. Therefore, charging must be stopped periodically in order to measure the battery voltage. Equalizing during charging requires an external power transistor with low on-resistance to achieve battery equalization, which will have the same limitations as equalizing during discharge.


Balance management process design is very important in any kind of lithium ion battery system. Now balance management, whether it is an electric forklift lithium ion battery system or a new energy vehicle lithium ion battery system, is inseparable from balance management, and internal balance management of battery assembly Among them, whether it is a traditional lead-acid battery or the current popular lithium-ion battery, the performance is not the performance of a single cell, but more depends on the balance management performance of the overall lithium-ion battery pack.