The Process of Battery Assembly
Have you ever wondered how a Lithium Battery is assembled? If you do, then read carefully this article. This passage talks about the process of battery assembly and the detailed information that enables better battery quality. In short, there are six steps to assemble a battery.
1: Capacity Testing
The first step is capacity testing. After shipped, the battery cells are usually tagged with parameters such as voltage, capacity, resistance and so on. At the beginning of battery assembly, the cells are sampled to check the accuracy of the parameters tagged in order to pack the cells with similar parameters in the next step. A pack with similar cells can work more stable and is likely to have a longer life.
Before packing, the voltage of the cells is tested again. The large difference in the voltages is likely to have a negative impact on the life of the battery pack or cause other cells inside the pack to over-charge.
The second step is packing. Battery cells are divided into groups according to the difference of the parameters. The cells in the same group should possess similar parameters to form a pack. To reconfirm that the cells ready to be packed have close parameters, the voltage of the cells is tested again before packing. Because a large difference of voltages would have a negative impact on the life of the battery pack or cause other cells inside the same pack to over-charge. During the process, insulation is important. Each cell needs to be insulated from one another by fishpaper. Each battery pack should be isolated from other packs by epoxy board.
The third step is welding. The purpose of welding is to connect the battery cells in series or in parallel in order to obtain the voltage or the capacity required. As known to all, the series connection rises the total voltage of the pack while the parallel connection increases the total capacity.
4: installing the BMS
The forth step is installing the BMS, namely Battery Management System, which prevents the battery from overcharge, controls the discharging current and balances the voltage of the cells. First, the BMS should be fixed inside the battery case. In the meanwhile, a wiring harness is added to the battery pack. And then, link the red positive cable of the BMS with the positive pole of the battery and connect the black negative one with the negative pole. Finally, test the screen to check whether the state of the battery can be shown through the screen. The battery can switch to communication mode after having installed the BMS. With the 485 communication cable, the detailed information of the battery can be shown on a computer or through an inverter.
5: Aging Test
The purpose of this step is to stabilize the performance of the battery. The aging test is to charge and discharge the battery pack, imitating the actual use of battery and testing the capacity of the battery pack.
Packaging is the final process of the battery assembly. When the aging test is done, the battery is added to a cover plate and then loaded cautiously into a packaging box with accessories such as brackets, 485 communication cables, screws, and so on. Eventually, the battery is now ready to be sold.
In conclusion, there are six steps in total to assemble a battery. Capacity testing, packing, welding, installing the BMS, aging test, and packaging. During all these processes, the quality of the battery is strictly assessed by several tests. Now all the secrets of battery assembly have been revealed.