Spot welding strips and tabs onto batteries in order to make battery interconnects and larger battery pack assemblies is a common production technique. Typically, battery interconnects are made from nickel strips, ideally designed with bifurcations and projections which are then resistance welded using parallel gap or step welding methods. For best and repeatable results, such methods rely on the quality of the weld heads, electrodes and power source.
With a constant drive to increase power handling and reduce losses, high-end battery pack manufacturers are looking for methods to attach more conductive interconnects, such as aluminium and copper, while additionally trying to reduce costs through simplifying the interconnect design. Such requirements often negate the possibility of using resistance welding methods because the interconnect is simply too conductive.