Quick Answer

Start With Your Battery Pack, Not the Machine

For a new battery pack project, basic information normally starts with the cell and finished pack.

A supplier asking these questions before quoting is in a much better position to recommend the correct equipment than one that immediately offers a standard production line.

Check Whether the Manufacturer Understands Different Battery Pack Processes

There is no single assembly process suitable for every lithium battery pack.

Cylindrical Battery Packs

A cylindrical battery pack production process include cell capacity grading, insulation paper application, voltage and internal resistance sorting, CCD inspection, spot welding, BMS testing, battery pack testing, packaging and aging.
Depending on production volume, these processes can be completed with standalone machines, a semi-automatic production arrangement, or a more highly automated system.
Spot welding is particularly important because the machine configuration must match the connecting material, thickness, pack dimensions and welding layout.

Prismatic Battery Packs

Prismatic battery packs involve a different set of processes. For larger ESS packs, production include cell OCV and internal resistance testing, stacking, pressing, polarity inspection, terminal treatment, laser cleaning, laser welding, BMS installation, EOL testing and airtightness testing.
Large-format cells also introduce additional requirements for material handling, module compression, fixtures and production-line layout.
For this reason, a manufacturer that has experience only with cylindrical battery equipment may not necessarily be the right supplier for a large prismatic ESS assembly project.

Make Sure the Recommended Automation Level Matches Your Production

More automation does not automatically mean a better production line.
A fully automatic line can reduce manual handling and improve production consistency, but it also requires a larger initial investment and is less economical when production volume is still low or product specifications change frequently.
Semi-automatic production can be a better starting point for pilot production, multiple SKUs and businesses that expect their production volume to increase gradually.
A useful example comes from a cylindrical battery pack project based mainly on 21700 cells. The customer planned several pack configurations, including 2S4P, 6S3P, 6S4P and 8S5P. Initial production was expected to be only 500–1,500 packs per month, by 3,000–7,000 packs per month and potentially up to around 15,000 packs per month after expansion.
In this situation, immediately purchasing a large fully automatic line would not necessarily be the most practical approach. A phased equipment configuration using standalone or semi-automatic machines can support initial production while allowing additional equipment to be added as output increases.
This is an important point to discuss with any potential manufacturer:
Ask why a particular level of automation is being recommended, rather than simply asking how automatic the line can be.

Check Machine Compatibility Against Your Actual Product Range
Machine compatibility should be evaluated carefully.
A statement such as “supports 21700 cells” does not automatically mean the equipment is suitable for every 21700 battery pack.
For example, a customer developing cylindrical packs may use the same 21700 cell format across several products but manufacture packs ranging from compact 2S4P designs to an 8S5P pack containing 40 cells. Fixtures, welding travel, working area and material handling requirements can therefore change significantly.
The connecting material also matters. One project may use 0.15 mm pure nickel, while another may require 0.20 or 0.25 mm material, slotted strips or different material combinations.
When comparing manufacturers, ask them to confirm compatibility according to the actual pack rather than only according to the cell diameter.
The same principle applies to prismatic cells.
For an ESS project using 3.2V 314Ah cells, the customer’s finished battery pack was specified at 332.8V and 314Ah with a 1P104S configuration. The pack dimensions were approximately 2180 × 790 × 250 mm, and the connection design used 2 mm aluminum busbars.
Those details directly affect stacking, compression, welding, transport, fixtures and overall line layout.

Evaluate the Manufacturer’s Ability to Configure a Complete Process
For a single machine replacement, it may be enough to work with a specialized machine supplier.
For a new battery pack production project, however, the interaction between machines becomes much more important.
Cell sorting capacity should match downstream assembly capacity. The welding process should be suitable for the selected connecting material. Testing equipment should cover the electrical specifications of the finished pack. The production layout should provide enough space for operators, intermediate storage, material movement and future expansion.
A supplier providing a complete battery pack assembly solution should therefore be able to explain not only what each machine does, but also why it is included in the process.
For example, ACEY’s semi-automatic cylindrical battery pack solution combines processes such as cell grading, insulation paper pasting, voltage and internal resistance sorting, CCD inspection, spot welding, BMS testing, comprehensive testing, packaging and aging.
For prismatic battery packs, the equipment configuration changes to match processes such as cell sorting, stacking and pressing, laser cleaning, laser welding and pack testing.
The difference between these solutions illustrates why equipment selection should begin with the battery pack rather than with a fixed machine list.

Pay Attention to Welding and Connection Requirements

Welding is one of the areas where incomplete project information can easily lead to the wrong machine selection.
For cylindrical battery packs, the supplier should understand the nickel strip material, thickness, shape and welding pattern.
For prismatic battery modules, the discussion instead involve aluminum or other busbar materials, busbar thickness, terminal construction and whether the connection will be made through laser welding or mechanical fastening.
These details affect the welding method and equipment configuration.
Before confirming a welding machine, it is useful to provide drawings or samples whenever possible. A supplier can then evaluate the actual joining structure rather than making a recommendation based only on the cell model.

Do Not Ignore Testing Requirements

Battery pack assembly does not end after the cells are connected.
The finished battery pack needs to be checked according to its electrical and safety requirements, and the required test range can vary considerably between products.
In the previously mentioned cylindrical project, for example, the customer required the final testing equipment to support at least 150A continuous current and up to 300A peak current.
A smaller tester that is otherwise suitable for the pack voltage would therefore not meet the project requirement.
When discussing equipment with a manufacturer, the testing stage should be considered together with the assembly process rather than added as an afterthought.
Depending on the project, the production system may include cell charge-discharge testing, BMS testing, comprehensive pack testing and battery aging equipment.

Consider Product Changes and Future Expansion

Battery pack manufacturers rarely produce exactly the same product forever.
New cell suppliers may be introduced. Pack capacity may increase. Additional SKUs may be added, or production may move from pilot quantities to higher-volume manufacturing.
This makes flexibility an important part of machine selection.
For the 21700 cylindrical project discussed above, the customer planned to use Samsung INR21700-50S cells as a primary option while also considering equivalent 21700 cells. The customer also wanted the equipment to provide flexibility for 18650 and other common cylindrical formats in future product development.
Production space was expected to increase from approximately 500 m² initially to a preferred scalable facility of around 700–900 m².
In a case like this, fixtures, machine working ranges and factory layout should be considered with future products in mind.
It does not mean every machine must support every possible battery. It means that the manufacturer should identify which parts of the system can be adjusted and which changes would require additional or replacement equipment.

Ask About Factory Layout Before Ordering a Complete Line

Available production space can influence equipment selection just as much as capacity.
A large automated ESS line requires space not only for the assembly equipment itself but also for material loading, operators, inspection, intermediate storage, maintenance and finished products.
For example, the 314Ah prismatic ESS project had an available workshop area of approximately 84 × 60 meters. This gives the equipment supplier a real boundary when planning machine positions, conveyors and material flow.
For smaller cylindrical battery production, the same consideration still applies. A modular arrangement of standalone machines may fit the available factory better and can make later expansion easier.
Before ordering a complete line, ask the manufacturer to provide a preliminary production layout based on your actual workshop dimensions.

Compare Suppliers Based on the Proposed Solution, Not Only the Quotation

Two quotations with different prices may not represent the same production solution.
One supplier may include cell testing, sorting, welding and finished-pack testing, while another quotation covers only the assembly stations. One may design fixtures for several pack models, while another quotation is based on a single configuration. Testing ranges, automation level, data functions and auxiliary equipment can also differ.
A meaningful comparison therefore needs to consider the scope of supply together with the price.
When reviewing quotations, check which processes are included, which machines are optional, which product formats are supported, what customization is required, and what would need to be purchased later if production increases.
This makes it much easier to understand the real investment rather than comparing only the final quotation amount.

Check the Manufacturer’s Project and Customization Capability

Standard machines work well when the product matches standard production conditions. Battery pack projects, however, often contain requirements that cannot be solved by simply selecting equipment from a catalog.
Fixture dimensions may need to change. Welding travel may need to increase. A larger cylindrical cell may require a modified machine structure. Production data may need to connect with a customer’s MES. Conveyor arrangement may need to fit an existing factory.
For this reason, it is useful to evaluate whether the supplier has engineering capability in addition to machine manufacturing.
ACEY provides battery pack assembly equipment for cylindrical, prismatic and pouch-cell applications, including semi-automatic and automatic assembly solutions. Its equipment range also covers battery cell testing and finished battery pack testing, allowing these processes to be considered together when planning a production system.
For customized projects, the equipment configuration can be determined according to the customer’s battery specifications, pack design, production capacity and factory conditions rather than using the same standard line for every project.

Verify Equipment Before Shipment

Before a customized machine or production line leaves the manufacturer’s factory, the agreed production functions should be verified.
For a battery pack project, this is more useful when testing is based on the actual product or representative samples rather than only demonstrating that the machine can run.
Key points should include whether the machine can handle the specified battery dimensions, whether the required process can be completed correctly, whether the welding or testing parameters meet the agreed range, and whether the production sequence works as intended.
For a complete line, buyers should also clarify the acceptance procedure in advance so that both parties know what will be checked before shipment.

After-Sales Support Still Matters — But Check What It Actually Includes

“Good after-sales service” is too general to be a useful selection criterion.
Instead, ask what happens after the machine arrives.
Confirm whether the supplier provides installation guidance, operating manuals, machine training, remote technical support, spare parts and ongoing maintenance support. For customized lines, also clarify how software or process adjustments will be handled if the battery product changes later.
ACEY provides OEM and ODM services as well as 24/7 after-sales technical support for battery equipment projects. For international customers, these capabilities are particularly important because communication and troubleshooting often need to continue after equipment delivery.

Questions to Ask Before Choosing a Battery Pack Equipment Manufacturer

Before requesting a final quotation, it is useful to check whether the supplier can clearly answer the following questions:

Conclusion

Choosing a lithium battery pack assembly machine manufacturer should begin with your battery product, not with a machine catalog.
A capable supplier should be able to understand the cell specification, pack configuration, joining materials, electrical requirements, production target and available factory space before recommending equipment.
For a small or developing cylindrical battery operation, this may mean starting with flexible standalone machines and gradually increasing automation. For a high-volume 314Ah ESS project, it may require an integrated automated line combining cell handling, stacking, compression, laser processing, testing and data traceability.
The right manufacturer is therefore not necessarily the supplier offering the largest production line or the lowest quotation. It is the one that can explain clearly how each part of the proposed equipment matches your battery pack and production plan.
ACEY New Energy provides lithium battery pack assembly equipment and customized production solutions for cylindrical, prismatic and pouch batteries. If you are planning a new battery pack production line, providing your cell specifications, pack configuration, connection materials, expected capacity and available factory space is a practical starting point for equipment selection.

FAQ
What information should I provide before requesting a battery pack assembly line quotation?
Start with the battery application, cell type and dimensions, pack voltage and capacity, series-parallel configuration, maximum pack size, connecting material, expected production capacity and available factory space. Pack drawings and samples are also helpful when available.

Should I choose a semi-automatic or fully automatic battery pack assembly line?
It depends mainly on production volume, product variety, labor requirements and investment plan. Semi-automatic equipment is more flexible for pilot production and multiple SKUs, while higher-volume and relatively stable products may justify greater automation.

Can one battery pack assembly line produce different battery packs?
Some equipment can support multiple products through adjustable settings or interchangeable fixtures, but compatibility should be confirmed using actual cell and pack dimensions. Supporting the same cell type does not automatically mean every pack configuration can run on the same equipment.

What equipment is needed for a cylindrical battery pack?
Depending on the process, equipment include cell grading and sorting machines, insulation paper sticking machines, spot welders, BMS testers, comprehensive battery testers, packaging equipment and aging systems.

What equipment is needed for a prismatic ESS battery pack?
The process include cell OCV and internal resistance testing, stacking and pressing, polarity inspection, laser cleaning, laser welding, BMS installation, EOL testing, airtightness testing and related material-handling equipment. The exact configuration depends on the module and pack design.

Why does the manufacturer need the nickel strip or busbar specification?
Material type, thickness and geometry affect the welding process and machine configuration. Providing this information helps the supplier determine whether spot welding, laser welding or another connection method is suitable.

Can a battery pack assembly line be expanded later?
Yes, if expansion is considered during the initial design. Modular standalone equipment can be added gradually, while automatic lines can be planned with additional stations or increased capacity. The expansion method should be discussed before the first equipment purchase.

How should I compare quotations from different battery equipment manufacturers?
Compare the complete scope rather than only the total price. Check the included processes, machine specifications, compatible battery sizes, testing ranges, automation level, fixtures, auxiliary equipment, customization, installation and after-sales support.