Choosing an aluminum busbar for use in a lithium battery pack is not just about picking the right piece of metal based on width and thickness. The busbar must be designed according to the battery layout, must be able to handle the current load, and must be compatible with the connection type, in addition to fitting in the allotted space. Even a specific change in the busbar size, holes, bends, or thickness can have huge consequences for the final design of the battery pack.

For this reason, battery manufacturers usually require custom busbars to be made according to their specifications instead of using commercial metal products.

Adinath Enterprises produces custom-made aluminum busbars for various applications in fields of electrical and battery equipment, including designs based on certain clients’ requirements and technical specifications.

What Is an Aluminum Bus Bar in a Lithium Battery Pack?

An aluminum busbar is an electrical metal part that connects the battery cells, modules, or some electrical points in a battery system.

The design of the aluminum busbar for lithium battery packs highly depends on the following factors:

• Required current amount

• Configuration of battery cells

• Space available for installation

• Adjustment on the connection

• Thickness and width of busbar

• Required slots and holes

• Angle of bends

• Needed insulation

• Manufacturing tolerances

In prismatic lithium battery packs, busbars can be built according to battery pack configuration and cell terminals.

Why Busbar Design is Important in Lithium Battery Packs

The function of battery busbars is straightforward—to provide electrical connection between terminals. However, their design is significant for many other reasons.

1. Current carrying capacity

The busbar must have sufficient cross-sectional area for the designed current.

In the case of aluminum busbars, width and thickness together determine the cross-sectional area. The universal current capacity formula cannot be applied here.

Other factors, including temperature rise, installation conditions, airflow, length, number of buses, and characteristics of nearby equipment, should be considered in designing the busbar.

This is why the busbar dimensions must not depend on the size tables.

2. Space Availability

Battery packs are typically designed with minimal space.

A straight busbar can work well electrically, but it occupies more space than a busbar that has been bent and shaped to match. A busbar must be designed to utilize the available space and connect the necessary points without excessive material and routing.

3. Connection Method

The connection method should be defined before the busbar is designed.

The busbar may need to have:

• Holes for bolts

• Slots for a specific installation arrangement

• Flat portions

• Bent parts

• Features for the customer’s welding process

• Insulation or insulating sleeving if needed

For instance, Adinath Enterprises produces aluminum busbars ready for laser welding according to the customer specifications.

How to Select the Suitable Aluminum Busbar

There is no single size of aluminum busbar suitable for all lithium battery packs. Begin with the electrical and mechanical needs of your application.

1. Determine the required current

Ascertain the continuous and peak currents that the busbar will have to carry.

This is the basis for determining the cross-sectional area of the conductor.

A simple rule of thumb used in determining the size of conductors is

Cross-sectional area = Width × Thickness

However, this should not be taken as a complete calculation of the current-carrying capacity. The actual permissible current depends on the climate and thermal conditions.

2. Determine the required thickness and width

Now that you know what your electrical requirements are, it is time to determine the dimensions of the busbar.

While the increase in cross-section will offer improved current-carrying potential, increasing the dimensions may not always work.

3. Check the configuration of cells.

Prismatic, pouch, and cylindrical battery cells feature different arrangements of connections.

In the case of prismatic battery cells, the design of a busbar has to meet certain parameters:

• The position of terminals

• The spacing between cells

• Series or parallel connections

• The module arrangement of the busbar

• The clearance available for operation

That is why a busbar that has been specifically designed may be better than adapting a standard one.

4. Account for slots, openings, and bends.

These features should not be an afterthought.

The placement and size of slots or openings influence the assembly, while bending should be done in a precise way so that the busbar is prepared for further operation.

A good manufacturing drawing indicates the specifications, limitations, and crucial points.

5. Pay attention to the thermal characteristics.

If there is current, then it is heat too.

Thus, the busbar use should be governed by:

• Continuous current

• Peak current

• Ambient temperature

• Heat dispersion

• Resistance of connections

• Conditions of use

• Temperature limits

Busbars made of aluminum and copper

Both aluminum and copper can be used for electrical connections.

Copper has higher conductivity and is often preferred in situations that require small size and high conductivity.

Aluminum has lower density and is advantageous when weight is a significant factor.

Choosing one of the two materials depends on many factors involved in the application rather than taking the conductivity alone into account.

The type of busbar to go ahead with for battery manufacturers may also be determined by the terminals of the cells, assembly technology, limitations in space, mechanical requirements, and overall design of the pack.

Common Mistakes to Avoid When Choosing Battery Busbars

Before manufacturing begins, several issues can be sidestepped.

Choosing a standard busbar size

A theoretical busbar size might look fine on paper but might not actually work with the battery design.

Focusing only on current rating

While current rating certainly is important, it’s not the only thing that should be taken into account. Other factors, such as mechanical fitting, temperature escalation, type of connection, and tolerance, should also be taken into account.

Making a decision on busbars before the design of the battery

The busbar should be assessed in cooperation with the entire assembly.

Changing the arrangement of the cells afterwards may change the holes, bends, and entire busbar design.

Forgetting about tolerances in manufacturing

Even if the drawing includes the correct nominal dimensions, tolerances of critical features should be accounted for at the same time.

Considering all aluminum busbars are identical

Aluminum that varies in grades, thicknesses, shapes, and finishing should be used differently for specific needs.

Why Custom Busbars Are Beneficial for Battery Manufacturers

Custom manufacturing is particularly significant when it comes to the battery pack design and architecture.

Rather than imposing a rigid design based on the standard busbar, the busbar can be made according to the requirements of the client.

Adinath Enterprises considers its clients’ specifications and manufactures made-to-order aluminum busbars that include:

• Requested dimensions and thickness

• Pattern of holes as required

• Arrangement for adjustments

• Bending and forming

• Actual sizes and allowable deviations

• Insulation as required

• Required finish.

Custom manufacturing can include processes like precision cutting, punching, bending, drilling, and dimensional inspection.

Useful Buyer’s Guide for Aluminum Battery Busbars

Before reaching out to a busbar producer, please pay attention to the following points:

Electrical Criteria

• Continuous current rating

• Maximum current rating if applicable

• Voltage rating

• Battery type

Mechanical Criteria

• Overall dimensions

• Hole and slot positions

• Bend angles

• Bend locations

• Available installation area

Material Criteria

• Aluminum grade

• Thickness

• Surface treatment

• Insulation specifications

Production Criteria

• Engineering design

• Specified tolerances

• Prototype number

• Number of pieces being manufactured

• Quality check specifications

With a well-made drawing, it will be easier for the producer to understand what needs to be produced.

How Adinath Enterprises Helps with Custom Aluminum Busbars

Adinath Enterprises manufactures aluminum and copper busbars and supplies custom busbars based on customer specifications.

In battery applications of lithium-based batteries, the company manufactures aluminum busbars according to required dimensions, holes, bends, and connection requirements.

If there are battery applications requiring laser joining of busbars, Adinath Enterprises manufactures aluminum busbars that are ready for laser welding, and the laser welding process is carried out by the battery manufacturer.

This drawing-based method works well if a standard busbar is not suitable for the battery configuration.

Frequently Asked Questions

What size of aluminum busbar is used in a lithium battery pack?

The right size depends on the current, allowable temperature rise, busbar length, installation conditions, material, and design of the battery. The width and thickness must be determined according to the full range of electrical and mechanical requirements.

What is the way to compute aluminum busbar size?

The first step is to calculate the cross-section area of the conductor, which is width × thickness. However, the resizing of the busbar should also take into account the current, thermal conditions, and installation and connection requirements.

Can aluminum busbars be used in lithium battery packs?

The answer is yes. Aluminum busbars are utilized in a variety of battery applications where their electrical, weight, and mechanical characteristics match the design requirements. However, the appropriate materials, dimensions, and methods of connection still have to be determined.

Can one customize aluminum busbars for prismatic cells?

Yes. One can manufacture custom aluminum busbars based on given prismatic cell layouts, along with different holes, slots, bends, and other details.

What type of information do you need to provide for customized busbars?

The best option is to provide a technical drawing indicating the material and thickness needed, dimensions, bolt and hole positions, bends, awkwardness, and finishing.

Does the manufacturer make laser welds busbar for battery packs?

Yes. The manufacturer makes aluminum busbars for laser welding purposes as required by the clients but does not perform laser welding on the battery packs.

Are custom-designed busbars possible?

Yes. The manufacturer manufactures custom-made copper and aluminum busbars based on provided drawings as well as technical specifications.

Making the Right Choice of Busbar by Designing the Busbar Right

The right busbar is not simply the one available in the widest or thickest dimensions. Instead, it should account for current carrying capacity, thermal performance, physical dimensions, and connection of busbars and battery packs.

If you are a manufacturer who is engaged in prismatic lithium batteries, a drawing-based custom busbar will ensure easy and accurate assembly.

If you already have a busbar layout and battery connection needs, you can count on Adinath Enterprises for manufacturing your required custom busbar in full conformity with your specifications.