1. The circuit board of this spot welder can be used for welding 18650/26650/32650 lithium batteries. Advantages: portable, stable, reliable and durable. 2. Users need to bring their own 12V battery for power supply, the welding current is about 90A~130A, and it is easy to weld the common 0.1mm~0.12mm nickel plated sheet. Please make that your battery can have a current 90A, otherwise you will not be to weld! 3. A battery with a discharge current will directly affect the welding effect. The following batteries are recommended: 20-45ah Lead-acid batteries with good performance and small internal resistance (internal resistance less than 10 milliohms, discharge current 90A), such as a new car battery! 3.5-5.5ah 3S model airplane lithium battery pack around 45C; 30-35ah capacity pack. 4. Power requirements: Spot welding is welded by the principle of rapid local heating and cooling by high current, Need sufficient current supply, generally 0.1-0.15 nickel plated sheet welding current About 90-150A, so the working power of the circuit board must be or equal to 150A. 5. The following battery packs can be used as working power: 12V car starting power supply, 3S high-rate battery pack for model airplane, three-string high-rate lithium battery pack, 40900 3-string battery pack, lead-acid battery with good performance above 12V 20A. Calculation formula: capacity X discharge rate = load capacity Take 4000ma aeromodelling battery as an example, the discharge rate is 45C (4AX45C = 180A) Instructions for use: Function buttons: 1, used to switch the machine, 2 used to switch gears! When the power is turned on, the default is the . Press the button for 2 seconds to release The gear is increased by one gear, and the buzzer sounds and the LED flashes corresponding to the number of gears. For example: the 3rd gear, the buzzer sounds three times, the LED flashes 3 times, a total of 5 gears. The spot welding intensity is gradually strengthened from the 1st gear to the 5th gear 5 is the strongest! After the 5th gear, press and hold the button again. It will power off. In the off state, press and hold the button to power on, and the gear will return to the colour: black Material: PCB+plastic+metal Package Contents: 1 x Circuit board 4 x Bronze noses 4 x Screws 1 x Buzzer 1 x nickel sheets 1 x Capacitor 2 x Welding pens 2 x Input wires 2 x Heat shrinkable tubes Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.