The present disclosure relates generally to a welding process for a battery module. In an embodiment, a system for welding two components in a battery module includes a laser source configured to emit a laser beam onto a workpiece having a first battery module component and a second battery module component. The system also has an actuator coupled to the laser source and configured to move the laser beam along a first axis and a second axis and a controller electrically coupled to the laser source and the actuator. The controller is configured to send a signal to the laser source and the actuator to form a sinusoidal lap weld on a surface of the workpiece, such that the first battery module component is electrically coupled to the second battery module component.