Cylindrical battery pack machine
Demonstrate shows how to assemble a cylindrical battery pack, explaining the assembly steps and the main equipment required.
Step 1: cell capacity grading. This is done using a cell grading machine. After purchasing cells from a cell supplier, we need to group cells of different capacities and assemble cells of equal or similar capacity into a battery pack. This ensures balanced capacity and maximizes efficiency across the entire pack. The function of a capacity grading machine is to perform a complete charge and discharge cycle on the cells, measure their capacity, and then group them. Since the cell must be fully charged and discharged, the entire process will take several hours.
Step 2: sticking highland barley paper. This is done using an automatic cell sticking machine. This machine applies highland barley insulating paper to the positive electrode of the battery cell, preventing short circuits between the positive and negative poles and increasing battery pack safety.
Step 3: cell sorting. This is done using a cell sorting machine. The cell sorting machine is equipped with a voltage and internal resistance tester. It first measures the cell voltage and internal resistance. Then, based on the settings, cells with the same or similar voltage and internal resistance are pushed into the same channel. Cells from the same channel are then assembled into a battery pack, ensuring a more balanced pack and achieving optimal charging and discharging performance.
Step 4: CCD visual polarity inspection, using a CCD cell polarity inspection machine. First, the cells are loaded into the holder. This step is usually done manually. In this case, the positive and negative polarity of the cells may be incorrectly installed. The CCD polarity inspection machine is designed to detect such errors. Equipped with a high-definition CCD, it takes a photo of the battery pack and compares it to a template stored in the computer. If the alignment is inconsistent with the template, an alarm is issued, notifying the operator to make corrections.
Step 5: spot welding, using a battery resistance spot welder. This is the most critical step in the entire battery pack assembly process. First, the nickel strip, cells, and holder are loaded into the spot welding jig, which is then placed into the spot welding machine. The spot welder will call the pre-set program to automatically complete the welding. In this way, all individual battery cells are connected through the nickel strip.
Step 6: BMS testing. The equipment used is a BMS tester. Its function is to test whether the BMS functions normally and whether it is consistent with the parameters in the specification provided by the supplier.
Step 7: BMS and accessories installation. The tools used are electric soldering irons, etc. This step is usually completed manually. Use an electric soldering iron to connect the protection board and the battery through the wiring harness. And complete the installation of connectors, insulating paper, etc.
Step 8: PVC shrink packing. The equipment used is a PVC shrink packing machine. Put the pre-cut PVC tube on the battery pack and then put it into the shrink packing machine. The PVC film is shrunk by heating, tightly wrapping the battery pack.
Step 9. Battery pack comprehensive testing. The equipment used is a battery pack comprehensive tester. Its function is to test various functions and parameters of the battery pack. For example, open circuit voltage testing, AC internal resistance testing, discharge testing, discharge overcurrent testing, short circuit protection testing, charging testing, and charging overcurrent testing. The entire testing process can be completed in just one minute.
Step 10: Battery pack charge and discharge aging testing. The equipment used is a battery pack charge and discharge aging machine. Its function is to perform a complete charge-discharge cycle on the battery, then obtain the battery pack capacity and charge the battery pack to the factory capacity. This equipment can be used to check whether the battery pack capacity meets the requirements. Since the battery must be fully charged and discharged, the entire process will take several hours.
That’s the complete cylindrical battery pack assembly process.