TYPE 1  This product is very useful in daily life, with an battery, it will become an energy storage spot welding machine for welding nickel pieces such as lithium batteries and nickel-chromium batteries practical, easy to operate and use, wide application range, has a long service life. Come on and try it. Features: There is a window on the back of the drive part, you can add copper or tin by yourself. The external pads for the LED and the on-board buttons are added to facilitate the connection of the LEDs and buttons on the board to other places. The upper and lower MOS design is bold and tinned to make the internal resistance smaller and the current stronger. Using 25V low internal resistance and high frequency capacitors makes the power supplies more stable. This circuit with a 12-V battery will become an energy storage spot welding machine for welding nickel pieces such as lithium batteries and nickel-chromium batteries. According to different configurations, the thickness can be about 0.1mm-0.15mm Specifications: Material: PCB Suitable for: 18650/26650/32650 lipo battery System voltage: 12-V-14.6V Working current: 90-150A Suggested battery: (not included) 20-45ah Lead-acid battery with fine performance and small internal resistance 3.5-5.5ah 45C 3S aeromodel lithium battery pack 30-35ah capacity 18650 battery pack Package size: 190 * 110 * 30mm / 7.5 * 4.3 * 1.2in Package weight: 110g / 3.9ounce Note: If the battery is pretty  and the internal resistance is very low, and then there may be large current overload. If you are not sure about your battery, it's better to extend the wire by around 1 meter with 2.5² or 4² wire, then it will reduce the risk of power tube burnt. Packing list: 1 * Main Circuit Board 2 * Input Wire 2 * Output Wire(with Welding Pen) 1 * Welding-Components Kit                 TYPE 2  Features: There is a window on the back of the drive part, you can add copper or tin by yourself. The external pads for the LED and the on-board buttons are added to facilitate the connection between the LEDs & buttons on the board and other places. The upper and lower MOS design is bold and tinned to make the internal resistance smaller and the current stronger. Using 25V low internal resistance and high frequency capacitors make the power supplies more stable. Switch Function: press the switch for 1.5 seconds (green light flashes, low power spot welding pulse is output every 3 seconds); press the switch for 1.5 seconds (the blue light flashes and the medium power spot welding pulse is output every 3 seconds); press the switch for 1.5 seconds (red light flashes, high power spot welding pulse is output every 3 seconds); press the switch for 1.5 seconds to turn off the machine. This automatic trigger spot welding machine can weld nickel plating (0.1mm~0.15mm) of 12V lithium batteries and nickel-chromium batteries with a 90A~150A welding current.