Use a lithium battery to the spot welder. It is recommended to use a fuse kit. Once the circuit is short-circuited, the spot welder may be burnt down, or it may cause electric shock, fire and other disasters. So in order to prevent accidents due to circuit overload, we can use fuses for overload protection.Add a fuse, in case the circuit is abnormal, the fuse will be blown, which effectively prevents damage to the spot welder and improves the safety in the event of a failure.Product Name: Battery Spot Welder FuseUsage: Short-circuited protectionModel Number: SQ-SW1color:BlackMaterial:MetalPackage Contents:1 x SQ-SW1 Battery Spot Welder 300A FuseOnly the above package content, other products are not included.Note: Light reflection 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.