Why do lithium batteries need a BMS battery management system?

There is a danger of explosion when the lithium battery is in a severely overcharged state, which causes damage to the lithium battery pack and also poses a threat to the life safety of the user. Therefore, it is necessary to equip the lithium battery pack with a set of targeted lithium battery management system BMS to effectively monitor, protect, energy balance and fault alarm on the battery pack, thereby improving the working efficiency and service life of the entire lithium battery.

 

 

(1) Security

 

 

Lithium batteries have poor safety and have defects such as explosions from time to time. In particular, lithium batteries with lithium cobalt oxide as the cathode material cannot be discharged at a large current, and their safety is poor. In addition, overcharging or over-discharging almost all kinds of lithium batteries can cause irreversible damage to the cells. Lithium batteries are also extremely sensitive to temperature: if they are used at too high a temperature, they may cause the electrolyte to decompose, burn or even explode; if the temperature is too low, the performance of the lithium battery will deteriorate significantly and affect the normal use of the device.

 

 

Due to the limitations of the battery manufacturing process, the internal resistance and capacity of each battery cell will vary. When multiple battery cells are used in series, the charging and discharging rate of each battery cell will be inconsistent, which leads to low utilization of battery capacity. In view of this, the lithium battery usually needs a special protection system to monitor the health of the battery in the actual use process, so as to manage the use process of the lithium battery.

 

 

(2) Maintainability

 

 

The capacity decay and power consumption of lithium batteries cannot be accurately predicted at low temperatures, which makes the maintainability of the equipment poor. Long-term online meters need to replace batteries regularly, and remote monitoring equipment has scattered work sites and long distances between sites. Therefore, the workload of battery replacement is huge and the cost is high.

 

 

In order to reduce the workload of maintenance and reduce maintenance costs, it is necessary for the lithium battery BMS management system to have an accurate state of charge estimation function to accurately grasp the state of charge of the battery, and to perform battery replacement work more purposefully; at the same time, the battery management system is also required to have better Low power consumption to reduce maintenance frequency and extend battery life. Therefore, for the long-term continuous power supply remote monitoring instrument, the reasonable design of the lithium battery BMS management system is of great significance to the maintenance of the equipment.