Automatic Double Sides Welding Head Battery Pack Spot Welding Machine Advantages 1) Induce load voltage, control voltage by feedback, and realize high quality welding. 2) Preheat, Main Heat's power mode, preheating before welding, to ensure stable welding quality. 3) Keep the continuity of energy density, shorten the welding time, and reduce the deformation and color of base metal. (Welding time controlled in microseconds, continuous output mode) 4) Easy to change from low