The Ultimate Guide: Screw-Type vs Laser-Welding Type Prismatic Cell

The EV industry and advanced energy storage have undergone rapid transformations, resulting in the necessity for manufacturers to come up with new battery designs that provide higher performance at lower cost. One of the most popular formats is prismatic lithium cells, which are widely used due to their high energy density, compactness, and structural integrity.

Today, leading global lithium battery manufacturers such as Highstar, EVE, Ganfeng, Highpower, Great Power, BAK Laser Cell, Gotion High-Tech (GHT), High Star, CATL, BYD, CALB, REPT Battero, Lishen Battery, SVOLT Energy, DMEGC, CBAK, Winston Battery, Sinopoly Battery, A-Grade suppliers, LG Energy Solution, Samsung SDI, and Panasonic commonly utilize these prismatic formats in EVs and ESS systems.

Nonetheless, there are two significant methods when it comes to the battery pack assembly of prismatic cells:

1. Screw-Type Prismatic Cell
2. Laser-Welding-Type Prismatic Cell

They are common in EV battery packs, ESS solutions, and high-power industrial applications. However, the controversy about the better method has increased as companies are more concerned with cost effectiveness, safety, and reliability over time.

Through this blog, you will be informed about both cell types, their perks, and the reason why laser Welding-Type prismatic cells are the industry’s preferred choice.

 

1. What Is a Screw-Type Prismatic Cell?

The screw-type prismatic cells consist of threaded terminals (for both poles) on which busbars are fastened with the help of screws/bolts.

The following are the benefits of this method:

• Disassembly and reassembly done at ease
• Serviceability done easily
• The design of modular pack is possible

The Working Principle of Screw-Type Connections

A busbar made of copper (sometimes aluminum) is placed on the terminals of the cell. Screws/bolts firmly hold the busbar down on the terminal thus the electrical path gets completed.

Where They Are Commonly Used :

• Development of new products
• Manufacture of battery packs of low to mid-volume
• Functions that necessitate regular maintenance
• Packs where changeability of components is essential

This design, while effective and tested over time, has its drawbacks—particularly in areas where mass production and cost-sensitive EV segments are concerned..

 

2. What Is a Laser-Welding-Type Prismatic Cell?

In laser-Welding-Type cells, the busbars are directly Welded to the terminals using precision laser welding. This creates a permanent, low-resistance, highly stable joint.

 

Key Advantages of Laser Welding :

• Strong metallurgical bond
• Lower internal resistance
• No need for mechanical tightening
• Faster assembly automation
• More compact battery module design

 

Laser welding significantly improves high-current performance and long-term stability.

 

3. Difference Between Screw-Type and Laser-Welding-Type Prismatic Cells

Here is a detailed comparison:

Feature	Screw-Type Prismatic Cell	Laser-Welding-Type Prismatic Cell
Connection Method	Mechanical (screws/bolts)	Permanent metallurgical welding
Busbar Material	Copper & Aluminum	Mostly Aluminum (cheaper & lighter)
Assembly Time	Slow, manual tightening	Fast, fully automated
Maintenance	Serviceable	Not serviceable (permanent)
Resistance Level	Higher due to contact gaps	Very low due to fusion bond
Cost	Higher (copper busbars + hardware)	Lower (aluminum busbars + no screws)
Thermal Performance	Slightly lower	Better due to solid Welding-Type joint
Suitable For	Prototypes, small batches	EVs, ESS, large-scale mass production
Initial Setup Cost	No major setup required; simple assembly	Laser welding setup is expensive (approx. ₹10–15 lakh)
Repair & Serviceability	Easily repairable at most service centers	Requires specialized machinery; limited repair options

 

4. What Makes Laser-Welding Prismatic Cells the Best Choice: The Main Reasons

There is no doubt that the trend in the industry is toward laser-Welding-Type prismatic cells as the new standard in mid-to-large-scale battery manufacturing.

 

1. More Price-Effective Battery System by Laser-Welding-Type Cells

One of the main advantages of the process is cost efficiency.

1. a) Copper-less Busbars

Laser welding is an exemplary technique for aluminum busbars which are:

• Less in weight
• Much more affordable than copper
• Very good in conducting for EV-grade applications

The wide variations in copper prices make the use of laser-Welding-Type aluminum busbars even more attractive for large-scale production.

1. b) No Screws Needed

In a screw-type battery pack, there will be:

• Bolts
• Nuts
• Washers
• Spring washers
• Terminal post machining

One of the main advantages of laser welding is that it stops the use of all those consumables.

1. c) No Structures for Screws in Terminals

Thermal cells needing screw-type terminals are those that have been enforced with the need of threads.

The making of the Welding-Type cells goes around the entire terminal assembly thus leading to:

• Less cost in producing
• Cell top that is more compact
• Production complexity that is reduced

Individually, these reasons cause laser-Welding-Type prismatic cells to be much more economical—especially in EV pack systems where there are hundreds of connections made.

 

2. Same Performance (or Better) Than Screw-Type Cells

Laser-Welding-Type designs, notwithstanding their lower cost, do not, in any manner, give up on performance.

To the contrary, the use of laser welding actually leads to the following improvements:

1. a) Electrical Performance

Joints created by welding offer lower resistance paths in comparison to mechanical contacts.

1. b) Thermal Stability

The laser welds are able to conduct heat away more effectively than the bolted joints, which could be subject to loosening from thermal cycling.

1. c) Long-Term Reliability

Over the years, bolts may lose their grip due to:

• Continuous vibrations
• Shock from the road (in electric vehicles)
• Frequent cycles of thermal expansion

Welds made by lasers are solid and not to be replaced—hence ideal for EV, UPS, and renewable storage.

1. d) Power Delivery

Favourable conductivity =

Lower IR drop → Higher efficiency → Longer battery life

Thus, you experience the same or even better performance in comparison with screw-type systems.

 

5. Unique Busbar Knowledge: What Busbars Are Used in These Cells?

 

This section provides you with a deep understanding that is very rarely available on the internet.

 

Busbars in Screw-Type Prismatic Cells

 

Given that screw terminals require a strong mechanical grip, the busbars must be:

 

• Copper (preferred) due to its good conductivity
• Thicker to cope with the mechanical stress
• Drilled with very accurate terminal holes
• Surface treated (Tin/Nickel) to ensure no oxidation occurs

 

Disadvantages:

 

• Heavy
• Costly
• More machining work needed
• More hardware required

 

Busbars in Laser-Welding-Type Prismatic Cells

The laser-Welding-Type connections have a remarkable impact on the entire busbar engineering landscape.

Laser welding makes it possible for:

• Aluminium busbars (the most common)
• Copper-Aluminum hybrid busbars
• Thin, lightweight, and flexible busbars
• Custom-made, multilayer busbars

 

Nonetheless, the following unique advantages make aluminum busbars the most suitable for laser-Welding-Type systems:

 

1. Aluminum is a more weldable material

Aluminum gets perfect, uniform welds during laser treatment without having to undergo preliminary surface treatment.

2. Battery module design that is lighter

This is a significant factor in EVs since lighter weight means a longer range.

3. Raw material and tooling costs are lower

This results in reduced cost of manufacturing cells to pack.

4. Design is flexible

Aluminum busbars can be extruded, stamped, or laser-cut into custom shapes for compact module design.

5. Tin plating in most cases is not necessary

The laser weld fuses to the metal, which means there are fewer oxidation problems as a result.

The cost and flexibility advantage, in addition, give an upper hand to aluminum busbars as a dominant option for the modern laser-Welding-Type prismatic cell packs.

6. Then, which is the better option?

Laser-Welding-Type Prismatic Cells Sacrifice Screw-Type Prismatic Cells

The reasons are:

• Cheaper
• Quicker process
• Joint stronger and thus more reliable
• Busbar materials are lighter
• No mechanical loosening
• Thermal and electrical characteristics are better
• Conductive for major-scale EV and ESS products

While screw-type systems can still be used in applications with frequent services, laser welding is the future for battery manufacturing that is cost-effective and high-performing.

 

Conclusion

Both types of battery cells, screw-type and laser-Welding-Type prismatic, present their own advantages, but the path of the industry is quite evident. When the production volume increases and the price drops, the laser-Welding-Type battery pack is the one that provides the highest efficiency, the best performance stability, and the lowest cost of ownership in the long run. The use of aluminum busbars cuts down the cost of materials and the laser welding process dispenses with all screws and threaded terminals, which makes the system lighter, less expensive, and of better quality than before.

If you’re considering sourcing precision-engineered aluminum or copper busbars for applications such as EV chargers, switchgear, battery modules, or customized prismatic cells, check out the solutions provided by Adinath Enterprises—a name you can trust for quality industrial busbar fabrication in India.