The increasing demand for electric vehicles has increased the need for high-performance batteries, and the so-called “jelly roll” cylindrical cell has shown promising results in terms of power density and storage capacity. In this field, manufacturing methods for joining delicate battery components are continuously improving, with laser technology emerging as a reliable solution. Recent advancements have enabled novel approaches to spatially modulate laser beams by adjusting the intensity profile delivered to the material surface. In this work, a 5 kW Multi-Mode Multi-Core infrared fibre laser is employed to investigate the impact of varying ring power distributions and speed during welding operations. The study utilizes thin copper and aluminium samples arranged in an overlap configuration to simulate the internal contact between tabs and the electrode roll. A partial penetration weld is required to prevent damage to the inner battery components and cross-sectional, mechanical, and electrical analyses are conducted to evaluate the impact of process parameters on bead quality. Additionally, a photodiode-based acquisition system is employed to detect variations in weld classifications and process parameters. The results support the possibility of increasing the resistance area of partially penetrated weld seams by modulating the spatial beam intensity profile. Experiments conducted with 816 W distributed across external rings exhibit good seam quality and mechanical strength of approximately 300 N for both the materials, making this approach viable for internal battery contact applications. Moreover, the available power enables high productivity rates, allowing welding at speeds where only the Gaussian beam would be ineffective.