R03 Carbon battery

What is the process of manufacturing R03 Carbon battery?

Cell sorting and grouping

The first step is the sorting and grouping of cells. The parameters for setting the grouping on the automatic sorting machine should be: (Take cylindrical cells as an example, ternary system batteries and lithium iron phosphate batteries)

Voltage difference 5mV (if there are many cells and the consistency requirements are strict, you can choose to set 3mV as the first gear);

Internal resistance difference 3m (if the consistency requirements are strict, you can set it to 1-2m).

The capacity difference cannot be screened on the automatic sorting machine, and it is necessary to use the capacity aging cabinet for capacity sorting and grouping. Before leaving the factory, the cells will be packed and shipped according to voltage, capacity, and internal resistance. When the cells arrive, the IQC of the PACK department will conduct random inspections, and the capacity difference is recommended to be within 1%.

Cell assembly fixture, automatic welding machine

When assembling the cell fixture, be sure to assemble it according to the positive and negative pole order of the cell in the PE engineer's SOP. Reversing the order will cause the cell to short-circuit. After setting up the automatic welding machine program, put the fixture battery cell in and start automatic spot welding.

After completing the automatic spot welding, the quality department shall inspect the automatically spot welded battery pack, and repair the leaking and explosion points.

Welding PCM/BMS

In this step, employees must wear anti-static wristbands to prevent PCM/BMS from being damaged by static electricity.

There are different steps according to different battery pack designs. If it is designed to spot weld the PCM on the battery pack, do not solder, and the quality department shall also spot weld the PCM to the battery pack.

If the PCM/BMS needs to be soldered, the PACK of the screw connection, the welding point, and the screw connection point shall also be inspected. Ensure quality. The voltage collection line shall be in the order of B-, B1... to B+; or unplug the voltage collection line and weld it. After welding is completed, check the collection line, and connect the BMS after confirmation.

Semi-finished product insulation

Fix and insulate the voltage collection line, wire, positive and negative output line as necessary. The auxiliary materials are usually high-temperature adhesive tape, barley paper, epoxy board, cable tie, etc. Be safe and do not superimpose and compress the voltage collection line or output wire of the battery pack, which may cause extrusion and damage and cause short circuit.

Semi-finished product test

After the battery pack is added with BMS, a semi-finished product test can be carried out. Conventional tests include: simple charge and discharge test, whole group internal resistance test, whole group capacity test, whole group overcharge test, whole group over-discharge test, short circuit test, overcurrent test. If there are special requirements, high temperature and low temperature tests, needle puncture tests, drop tests, salt spray tests, etc. are required. Special tests are destructive and random inspections are recommended.

Pay attention to the bearing capacity of the battery pack, such as whether the BMS can withstand high voltage during the whole group overcharge test; whether the BMS can withstand instantaneous high voltage and high current during the short circuit test; whether the BMS can withstand pulse current during the overcurrent test, etc.

PACK packaging

This step also depends on the design. But before packaging, the signal collection line and the insulation of the positive and negative poles of the battery pack must be done well.

PVC-packaged battery pack, overheat shrink machine. Ultrasonic sealed battery packs are put on ultrasonic machines. Battery packs with metal outer boxes are assembled in outer boxes. During this process, be careful to handle the battery packs with care to prevent collisions, squeezing, etc. The wires must be well insulated to prevent short circuits.

Whole group test

Set the parameters of the whole group tester, and test the battery pack on the whole group tester.

Important test items: shipping voltage, internal resistance, simple charging and discharging.

Optional test items: overcurrent, short circuit.

Packaging and shipping

Pack according to the size of the molded foam, and do not place it randomly. When transporting the battery pack, the most feared thing is that the internal packaging is empty. Make sure there is enough foam inside for buffering to prevent damage during transportation. For large battery packs, wooden frames should be arranged for shipment for safety reasons.

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