How to keep Battery Balance
In the process of battery use,usually we’ll have BMS with passive or active balance,but also we can do something for maintaining battery balance,it requires starting from multiple aspects such as charge and discharge management,temperature control,and regular maintenance,the following are specific methods:
1.Charge and discharge management
Using compatible charging and discharging equipment: Different batteries have different charging and discharging requirements,and compatible charging and discharging equipment can provide appropriate voltage,current,and charging algorithms based on the characteristics of the battery,ensuring that each battery in the battery pack can be charged and discharged under suitable conditions,reducing performance differences caused by improper charging and discharging.
Avoid extreme charging and discharging situations: do not charge or discharge,and stop charging in a timely manner when the battery is fully charged or close to full charge;when the battery level drops to a lower level but is not fully depleted,it is charged. Generally speaking,there are strict regulations on the charging cut-off voltage and discharging cut-off voltage of lithium batteries,for example,the common ternary lithium battery has a charging cut-off voltage of around 4.2V and a discharging cut-off voltage of around 2.75V,these standards should be strictly followed during use.
Control charging and discharging current: High current charging and discharging may cause uneven chemical reactions inside the battery, affecting battery balance,charging and discharging should be carried out within the rated current range allowed by the battery as much as possible,for some lithium batteries with a capacity of 2Ah,a charging and discharging current of around 0.5C (i.e. 1A) is more appropriate to avoid using excessive fast charging current or strong discharging load.
2.Temperature control
Maintain an appropriate temperature for battery usage: Control the temperature of the battery usage environment within a suitable range,generally speaking,the optimal usage temperature for lithium batteries is around 25 ℃,and try to avoid long-term use of the battery in high temperature (such as exceeding 45 ℃) or low temperature (such as below 0 ℃) environments,in high temperature environments,the battery can be placed in a well ventilated area;in low-temperature environments,appropriate insulation measures can be taken, such as wrapping the battery with insulation materials.
Installation of temperature management system: For some battery packs with high temperature requirements, specialized temperature management systems can be installed,such as liquid cooling systems,air cooling systems,etc,the liquid cooling system takes away the heat generated by the battery through circulating coolant,while the air cooling system uses a fan to force air flow to dissipate heat, ensuring uniform temperature of each battery in the battery pack.
3.Regular maintenance
Regular balanced charging: Every certain usage cycle (such as every 100 complete charge and discharge cycles),the battery pack is balanced once,and the power of each battery in the battery pack is made consistent through a balancing circuit or specialized balancing equipment.
Conduct performance testing: Regularly check the voltage, internal resistance,capacity and other performance parameters of the battery,establish a battery usage record,and record the data from each test. By analyzing the data,changes in battery performance and consistency issues can be detected in a timely manner,if it is found that the internal resistance of a certain battery has significantly increased or the capacity has significantly decreased, it should be dealt with in a timely manner.
Check battery connections: Regularly check the connections between the batteries in the battery pack for looseness and good contact,ensuring stable and reliable electrical connections between the batteries,and avoiding uneven charging and discharging of the batteries due to connection problems,which may affect battery balance.