Points to note during welding of lithium batteries

1. First of all, the battery cell should be uniformly arranged on the battery bracket according to the battery pack process specifications, and it should be noted that the positive and negative electrodes of the battery cell should not be placed incorrectly, otherwise it will cause the battery pack to short circuit.

2. Place the nickel sheet according to the technical design requirements of the battery pack.

3. Select the appropriate welding needle according to the demand

①1.7 straight welding needle: commonly used welding needle model, better versatility, suitable for 0.12mm-0.18mm nickel sheet.

②3.0 eccentric spot welding needle: Usually the front end is used to 1.7/2.0, because the welding needle is thick, it can weld thicker nickel sheets, and the thickness of conventional welding nickel sheets is between 0.15-2.0mm. After the end of the welding needle is consumed, stop the lathe processing and polish the end of the welding needle. Because the diameter is relatively large, the conductive effect is good, and the heat dissipation effect is good, which is conducive to welding. It is usually suitable for welding larger battery packs.

③ 6.0 convex spot welding needle is usually used for convex spot nickel sheet welding, on the battery pack quality requirements of high products, often produce vibration or impact of the battery pack, or current overload of the battery pack, you can use the convex spot nickel sheet welding, welding more convenient not easy to stick the needle. Such as drone battery pack, power car battery pack and so on.

4. Place the assembled battery pack on the welding platform, adjust the welding head or welding needle according to the height of the battery pack, and insist that the distance between the welding needle and the battery cell is 2-3mm.

5. Adjust the appropriate needle spacing and welding head pressure according to the demand.

6. Adjust the parameter power supply current after the power is turned on, and adjust the appropriate welding current according to the thickness of the nickel sheet.

7. During the welding process, no other impurities remain on the surface of the nickel sheet and the battery cell, otherwise there will be poor welding such as fire.

8. Solder joint evenly distributed, uniform arrangement, do not weld bias or solder joint between the gap between the positive and negative poles.

9. Pay attention to the number of solder joints. The welding battery pack is usually spot-welded twice to form four solder joints. Avoid virtual welding of solder joints to reduce the probability of virtual welding. Multiple solder joints have better conductivity and high robustness, but for ordinary battery pack welding, four solder joints are enough. The number of solder joints depends on the needs of the battery pack process design.

10. When spot-welding, pay attention to the work surface can not be placed conductive items, can not wear watches, rings and other metal items. Wear protective equipment such as goggles and insulating gloves.

11. Stop grinding the front end of the welding needle regularly to prevent impurities caused by oxidation of the surface of the welding needle from causing poor welding.

12. When welding a larger battery pack, an epoxy plate should be placed. Part of the welding is to cover the epoxy plate in this part, and then stop the welding of another part to prevent the occurrence of welding spatter.