Lithium Battery Pack Manufacturing Process Points

1. Core assignment group

  The first step is that the unit selection group of the battery should be set to the parameter of the group: (cylindrical battery and lithium iron phosphate battery)

  The voltage difference is 5mV (if the number of batches is large, the consistency requires strict, you can choose to set up 3mV as a gear);

The internal resistance is 3MΩ (1-2 mΩ if the consistency requires strict).

  Capacity differences cannot be filtered on the automatic sorting machine, and you need to pull up the old cabinet for the distribution. Based on the voltage, capacity, and internal resistance before the battery is shipped. When the battery is arriving, the Pack department IQC needs to be sorted and the capacity is within 1%.

2. Lithium battery pack, core with clamp, automatic spot welder

  When the electric core fixture is applied, it must be assembled in the positive and negative order in the PE engineer SOP, and the order is reversed will cause the electrical wire short. After setting the automatic welding machine program, the clamp is discharged and automatically spot welding.

  After the automatic spot welding is completed, the quality needs to check the battery pack of the automatic spot welding, the leaks, and need to be soldered.

3. Lithium battery pack welding PCM / BMS

  This step, the employee must have an electrostatic bracelet to prevent PCM / BMS being damaged by static electricity.

  There are different steps based on different battery packs. If it is designed as a PCM spot welding battery pack, it is not necessary to solder, and the quality also needs to be welded to the battery pack for spot soldering.

  If the PCM / BMS needs to be solder, the PACK of the screw is connected, the solder joint, the screw connection point needs to be inspected. guaranteed quality. Voltage acquisition line, need to be used in order B-, B1 ... sequentially to B +; or unplug the voltage capture line, welding, welding is completed, the acquisition interpolation is detected, confirmed, and then connect BMS after confirmation.

4. Semi-finished Insulation

  For voltage collecting lines, wires, positive and negative output lines, and perform necessary fixation and insulation. The excipient is conventionally a high temperature tape, blue paper, 3240 epoxy sheet, tie, and the like. There is a need to have a safety awareness, do not superimpose the battery pack voltage collection line or the output wire, which is easy to cause a short circuit to cause extrusion damage.

5. Semi-finished Test

After the battery pack plus BMS, it can be tested for a semi-finished product. General testing includes: simple charge and discharge test, whole group internal resistance test, whole set capacity test, whole group overcharge test, whole group overset test, short circuit test, overcurrent test. If there is a special requirement, high temperature and low temperature test, acupuncture test, drop test, salt fog test, etc., special lithium battery pack test, destructive, suggestion.

  It is necessary to pay attention to the ability of the battery pack. If the entire group is overcharge test, whether the BMS can resist high pressure; the BMS can withstand the transient high voltage high current; whether the BMS can withstand the pulse current when overcurrent testing.

6. Battery set pack packaging

  This step also needs to be designed. However, before the packaging, the signal acquisition line must be made, and the insulation of the positive and negative electrode of the battery pack.

  PVC packaging battery pack, over-heat shrinking machine. Ultrasound-gated battery pack, upper ultrasound machine. Battery group with metal outer boxes for outer box assembly. In this process, you need to pay attention to the battery pack to gently put it, avoid collision, squeeze, and so on. Wires should be insulated and avoid short circuit.

7. Whole Group Test

  The whole group tester sets the parameters, and the battery pack is tested on the battery pack.

  Main test items: shipping voltage, internal resistance, simple charge and discharge.

  Alternative test item: overcurrent, short circuit.

8. Packing Shipments

  Press the dichroic size box, do not place freely, when the battery pack is transported, the internal packaging is empty. Be sure to ensure that there is enough foam to buffer inside to avoid transportation. Big battery pack, safety, need to arrange a wooden frame shipping.