This is because the spot welding machine has not been debugged well. For nickel sheets of different thickness, different currents and delays need to be set at the same time, they are affected by the high strength material. the current to a smaller value, and materials with small resistance need to adjust the current to a smaller value. Increase the current, and the product should be clean and free of oil. In addition, the wear of the welding needle will also affect. the welding effect. The smaller the contact area between the welding needle and the nickel sheet, the higher the pressure and the better the welding effect.
If you are using an electric welder to convert aluminum tabs into nickel strips, you can use Violin 303B solder to flatten them, then solder to avoid the heat generated by spot welding at level of the part to be welded. The temperature is 400sandstone. For testing and further use, you can usually use an electric soldering iron to solder directly with M51 low temperature soft solder and use M51-F flux for soldering. The temperature may be higher when using a spot welder.