Which Is Better, Large-capacity Single Lithium Cell Or Small-capacity Single Lithium Cell?

Small-capacity single lithium cell emphasizes the failure of instantaneous consistency. In the battery group application, the consistency of the factory battery and the matching group is emphasized. The data that ignores the consistency is only the instantaneous consistency of many test elements on the time coordinate. As the time and the number of charge and discharge changes, the non-uniform divergence rate is gradually expanding as a function of time, and because the power management system cannot control the characteristics of the single cells in the parallel battery pack, it will eventually lead to a small capacity single lithium battery. A battery failure causes a group of modules to fail. This is an important and fundamental reason why electric vehicles have failed several months after the application of small-capacity single lithium batteries to load electric vehicles.

Large-capacity single lithium batteries reduce the assembly process of power batteries, which is more convenient for large-scale production, and fundamentally solve the shortcoming of short-term failure of small-capacity batteries when large-capacity power is required for operation.

Advantages of large-capacity single lithium battery:

1. Small internal resistance and good safety

When a large-capacity single lithium battery replaces an energy module that requires many small-capacity batteries in parallel, it has good consistency, and the data collected by the module through the BMS is credible. A battery that fails due to a short circuit of a single circuit of many batteries in parallel will quickly exhaust the power in other batteries and cause a fire. Therefore, the above drawbacks can only be avoided by using a single large-capacity battery. At the same time, since the internal self-reflow phenomenon of parallel batteries will not occur, under the same conditions, the larger the battery capacity, the smaller the internal resistance, and the lower the operating temperature. Compared with the parallel battery modules of the same capacity, the load capacity will be increased and the operating life will be extended.

2. Fewer connection points, lower failure rate

The fewer the power system connection points of the large-capacity single lithium battery, the lower the probability of accidents. At present, the industry is equipped with pure electric buses. If the power modules of 480V500Ah are connected in series with 10Ah, there are as many as 7,500 batteries. There are as many as 15,000 positive and negative connection points. However, only 150 single 500Ah batteries are used in series, which greatly reduces the probability of accidents.

3. The single-chip large capacitor of large-capacity single lithium battery, the power management system is controllable. Many battery packs caused by parallel connection can only reflect the data of one of the highest electromotive force batteries in the power management system. This blind spot of untestable monitoring is caused by Single large-capacity batteries are replaced and eliminated.

4. Solid polymer design, low temperature resistance and safer. The single large-capacity power battery manufactured by Shenzhou Giant Electric uses solid polymer structure to improve the low-temperature working ability, overcomes the liquid battery seepage, flammability and can only be placed vertically The limitation of the battery is that the battery can be placed horizontally and randomly, which expands the design space of pure electric vehicles and reduces battery damage caused by vehicle bumps.

5. Convenient for large-scale production and standard operations. Automated assembly lines can be used to uniformly carry out operations such as series operation and module boxing to meet the requirements of automotive-grade industrial accessories, achieve large-scale production of power modules at the lowest cost, and greatly reduce application costs.