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RMA Battery Pack Laser Welding: Faster, Stronger Connections with Advanced Laser Technology

09/05/2025

RMA Battery Pack Laser Welding: Faster, Stronger Connections with Advanced Laser Technology

 

As electric mobility, renewable energy, and portable electronics expand at record pace, the demand for high-performance battery packs is surging. A key factor in battery reliability, safety, and performance lies in how individual cells are joined into modules and packs. In this context, laser welding has emerged as a game-changing technology, offering unparalleled precision, speed, and strength. At the forefront of this transformation there is RMA, a leader in laser welding automation, delivering solutions that set new standards in battery manufacturing.

 

The Growing Role of Laser Welding in Battery Manufacturing

 

Modern battery production requires techniques that are both highly efficient and extremely reliable. Whether it’s welding of thin aluminium tabs, connecting copper busbars, or creating seals for battery enclosures, joining methods must operate at high speed without risk of sensitive components.

 

Laser welding provides a powerful answer. This non-contact method uses concentrated light energy to fuse metals quickly and precisely. Its high focus and minimal heat input make it ideal for working with demanding battery materials, enabling reliable, high-strength welds with minimal thermal distortion. With the ability to weld dissimilar metals with extreme accuracy, laser welding opens new possibilities for battery design and production.

 

Comparing Battery Welding Techniques

 

Battery pack assembly involves joining multiple materials – often thin foils, tabs, and terminals made of aluminum, copper, nickel, and steel. Several methods are commonly used:

  • Ultrasonic Welding: Relies on high-frequency vibrations to bond materials without melting them. It's well-suited for thin tabs and conductive foils but offers shallow bonding depth and limited mechanical strength. Sonotrode wear and design limitations can complicate frequent format changes.
  • Resistance Spot Welding: Utilizes heat from electrical resistance between two electrodes. Widely used for small cylindrical cells and nickel tabs, it’s fast and cost-effective but struggles with thick or highly conductive materials like pure copper. Electrode wear and inconsistent quality are additional concerns.
  • Arc Welding (e.g. Micro-TIG): Effective for thicker materials and special cases, but significantly slower than other methods. High heat input can damage nearby components, and the method requires skilled control and inert shielding gas.
  • Laser Welding: Combines speed, flexibility, and precision. It works with a wide range of metals and thicknesses, can produce both spot and seam welds, and is easily programmable. Because it’s non-contact, there is no electrode wear, and the focused energy reduces thermal impact on the battery cell.

Laser welding thus offers a unique combination of depth, speed, and control unmatched by other techniques.

 

 

The Advantages of Laser Welding in Battery Applications

 

Battery packs must meet demanding performance criteria – from high current delivery and vibration resistance in EVs to compact form factors in consumer electronics. Laser welding supports these needs with three major advantages:

 

1. Speed and Throughput

Laser welding is extremely fast. A well-tuned system can weld a cell connection in under 0.1 seconds, creating thousands of welds per shift. This is essential for scaling production to meet rising global battery demand. Systems like RMA’s Battery Welder Max support high-speed, high-volume manufacturing with minimal downtime, thanks to fast scanning heads, automated loading, and real-time quality control.

 

2. Precision and Quality

Laser beam can be focused to micrometre diameters, allowing precise weld placement and minimal distortion. Advanced vision systems and automated alignment ensure consistent welds across batches. A well-adjusted process can be spatter-less, producing clean joints and narrow heat-affected zones – all critical for compact and sensitive battery modules.

 

3. Strength and Reliability

Laser welding creates deep metallurgical bonds with low electrical resistance, crucial for power delivery in high-current applications. Weld geometry and penetration depth can be tailored to specific strength or thermal performance needs. Moreover, the process is repeatable and stable, making it ideal for EV battery packs that must survive thousands of charging cycles and mechanical stress.

 

RMA’s Battery Welder Series: Engineered for Performance

 

RMA has developed a complete portfolio of laser welding machines under the Battery Welder brand, each designed to meet different production scenarios:

  • BW Spot: A compact entry-level machine ideal for workshops and smaller manufacturers. Despite its size, it offers cycle times around 0.5 seconds per weld and supports both cylindrical and prismatic cells.
  • BW Flex: Designed for flexibility, R&D, and pilot lines. It supports fast format changes and all common cell types, making it a great choice for product development and short-run manufacturing.
  • BW Flex Turntable: Adds a rotary indexing table to improve efficiency. While one side is being welded, the other side can be loaded – doubling output in a compact footprint.
  • BW Max: A fully automated machine built for high-throughput production lines. It features robotic integration, advanced quality monitoring, and cycle time optimization.

These systems share a common characteristic: precision motion, sophisticated software, and advanced diagnostics. RMA’s proprietary BW Interface software makes it easy to configure weld patterns, adjust laser parameters, and ensure traceability – even in dynamic production environments.

 

Expertise and Innovation: More than Just Machines

 

RMA doesn’t only build machines – it offers full-cycle support. Through its Laser Application Center (LAC), RMA helps customers test, optimize, and validate welding processes for their specific battery formats. From early-stage prototyping to full production ramp-up, RMA provides guidance in process development, fixture design, and in-line monitoring.

 

This approach ensures that battery producers not only get cutting-edge equipment but also benefit from RMA’s deep application knowledge. Whether a client is assembling cylindrical 18650 cells or large prismatic EV modules, RMA delivers tailored laser solutions that improve quality and productivity.

 

Real-World Results

 

RMA’s technology is trusted by manufacturers across Europe and beyond. With installations in both industrial and laboratory settings, the Battery Welder series has become a go-to solution for producers seeking high-speed, high-quality welding. By combining automation, precision, and service, RMA helps its partners to reduce production time, improve battery reliability, and accelerate innovation.

 

Looking Ahead: Powering the Future of Energy

 

The electrification trend is only accelerating. As vehicle platforms shift to electric, grid storage grows, and new chemistries emerge, the need for reliable and scalable joining methods becomes more critical. Laser welding will continue to lead the charge – and with it, companies like RMA will play a pivotal role in shaping the next generation of battery technology.

 

With its proven platforms, application expertise, and commitment to innovation, RMA delivers exactly what modern battery manufacturers need: faster, stronger connections with advanced laser technology.

 

Sources

 

  1. RMA company website – https://myrma.eu
  2. Fraunhofer Institute for Laser Technology (ILT): “Laser Welding of Batteries for Electric Vehicles”
  3. Battery University – “Welding Battery Tabs”
  4. International Journal of Advanced Manufacturing Technology: "Comparative Study of Welding Techniques for Battery Applications"
  5. Laser Focus World: “How Lasers Power the EV Revolution”
  6. Tesla Battery Day presentation and associated patents
  7. Journal of Manufacturing Processes: “Joining Technologies in Lithium-Ion Battery Manufacturing”
  8. White paper: “Ultrasonic vs. Laser Welding in Battery Production,” Emerson / Branson
  9. ResearchGate: “Micro TIG Welding for Battery Busbar Connections”
  10. International Energy Agency (IEA) – Global EV Outlook

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