When a lithium battery pack overheats, most people tend to accuse the battery cells. However, in a number of situations, the cells are not at fault, but the reason for that overheating is the inadequate design of the busbar instead.

It is common for battery manufacturers to optimize their BMS and cooling arrangement and choose dedicated cells for the task when they realize the problem was a badly designed busbar that produced excess heat.

The excess heat will not only decrease effectiveness but also shorten battery lifespan, increase energy losses, cause problems with charging, and create issues with reliability over time.

That is the most important reason why custom-designed busbars are a popular solution chosen by manufacturers of electric vehicle battery packs, energy storage systems (ESS), home inverters, robotics, telecommunication emergency batteries, and lithium battery packs for industrial purposes.

At Adinath Enterprises, we design busbars around the customer’s battery pack’s not vice versa. The aim is not merely connecting the cells but creating the safest and most efficient current path that will allow keeping temperatures at a low level.

The Importance of Thermal Performance in Prismatic Lithium Battery Packs

A busbar transmits high levels of current between battery cells. As the current rises, the heat also increases. If the busbar is not designed correctly, the following complications may occur:

• High electrical resistance

• Voltage drop

• Hot spot development

• Non-uniform current flow

• Rapid battery cell deterioration

• Low charging and discharging efficiency

In the case of highly loaded current batteries, even a minimal resistance increase can produce much heat. That said, thermal performance must be considered long before making the battery pack, as the development of a busbar must be attended to first.

What Is a Custom Busbar?

The custom busbar is a precisely made conducting element created especially for customer-specific dimensions of the battery pack, current flow ability, cell configuration, and mounting method.

Unlike typical conductors, custom-made busbars are made with the following specifications:

• Length

• Width

• Thickness

• Hole location

• Material type

• Surface texture

• Welding or bolting features

The Effect of Busbar Design on Heating

The common belief is that thicker busbars would resolve issues with heating.

Such an assumption is incorrect.

The assortment of design features, which involves the following:

1. Choice of Material

One has to select a proper material as the first step.

Copper Busbars

Copper provides:

• Good conductivity

• Minimal resistance

• Maximal current capacity

• Good efficiency

Copper is usually selected when conductivity is desired.

Aluminum Busbars

Aluminum is more and more widely used for:

• EV battery packs

• Lightweight applications

• Laser-welded battery modules

Despite being less conductive than copper, proper calculation allows the use of aluminum while providing good performance and reducing weight.

Both copper and aluminum busbars have been produced by Adinath Enterprises with respect to the electric and mechanical requirements of their application.

2. Correct Busbar Thickness

The thickness of an aluminum busbar for prismatic cells is specified on the basis of such factors as

• Continuous current

• Peak current

• Ambient temperature

• Battery chemistry

• Duty cycle

• Space for installation

3. Current Path Optimization

Electricity will always prefer the route with the least resistance.

Any type of obstacle can cause local heating to be created.

A good busbar design entails:

• Smooth flow of current

• Even cross-section

• Even distribution of current

• Reduced resistance

These seemingly minor changes can still lower the temperature of operation considerably.

4. Precise Manufacturing of Busbars

Even a well-engineered busbar may not work if the processes are inaccurate.

• Punching, bending, drilling, finishing

• Perfect fit

• Reliable electrical contact

• Stable pressure in all areas

• Low contact resistance

This is particularly vital in automatic battery pack assembly.

How Adinath Enterprises Designs Busbars

Every battery pack has its own specifications.

Instead of providing a single product, Adinath Enterprises creates customized copper busbars according to drawings.

The process of making these busbars involves:

Understanding the specifications of a battery pack.

The engineering team checks:

• Type of battery cell

• Current

• Voltage

• Placement of cells

• Method of assembly

• Points of connection

• Conditions of installation

Choosing the Best Material

Customers can choose from the following materials depending on their application:

• Copper with high conductivity

• Aluminum with premium quality

• Copper that has been tin-plated

• Copper in its pure form

• Insulated Busbars

The choice of material will always depend on the desired performance specifications and not assumptions.

Designing for Production

The busbar is specifically designed to provide the following:

• Ease of installation

• Compatibility with laser welding

• Bolted connections

• Automation

• Accuracy in dimensions

This leads to speedy production and an improvement in assembly of battery packs.

Manufacturing with Precision

With the help of advanced technology, every busbar is:

• Cut

• Punched

• Bent

• Holes machined

• Finished

• Checked for dimensions

In the end, every busbar produced is exactly fitted without any adjustments.

Applications of Thermally Optimized Busbars

The custom busbars find their application in:

• Electric Vehicle (EV) battery packs

• Energy Storage Systems (ESS)

• Home inverter lithium batteries

• Solar storage systems

• Telecommunications backup batteries

• Industrial battery packs

• Automated Guided Vehicles (AGVs) and robots

• Uninterruptible Power Supply (UPS) systems

• Material handling systems

Every application differs in its thermal and current needs, which makes it much more effective than standard busbars.

Importance of Custom Busbars in Thermal Performance

Well-designed busbars generate more than just current flow.

Lower Resistance

Efficient current flow leads to less heat generated as well as energy losses.

Better Temperature Distribution

A constant flow of current avoids creating local hot regions in the battery pack.

Increase in Battery Life

Lower operating temperatures extend the life of lithium cells, thus providing longer service.

Higher Efficiency

Decreased resistance leads to fewer energy losses in terms of heat during charging and discharging.

Reliability

Consistent electrical performance improves the reliability of the battery packs.

Ease of Use

Due to custom dimensions, busbars are easy to assemble and thus minimize installation errors.

Custom Busbars vs. Standard Busbars

Feature	Custom Busbars	Standard Busbars
Designed for Battery Pack	✔	Limited
Optimized Thermal Performance	✔	Not Always
Accurate Fit	✔	Often Requires Modification
Current Distribution	Optimized	Generic
Manufacturing Efficiency	High	Moderate
Long-Term Reliability	Better	Application Dependent

Standard Problems in Busbar Design

Even knowledgeable battery makers run into problems in the course of development. 

The key challenges are:

• The wrong busbar thickness has been chosen

• Thermal expansion not being taken into account

• Unsuitable hole alignment has been carried out

• Inappropriate material grade has been used

• Overestimation of current peaks has been made

• Surface finishing has not been good enough

• Contact pressure is not suitable

• Manufacturing tolerances have not been considered in designing

Solving these issues in advance can be a huge time and cost saver during the production phase.

Expert Recommendations for Majority Thermal Performance

The key design principles that can help you achieve better results are as follows:

• Make the busbar design according to the current profile rather than just nominal values

• Take care not to introduce bends and small sections when they can be avoided

• Use the best quality conductive materials that meet the required standards

• Pay great attention to the making of contact surfaces so that the resistance is low

• Make sure the busbar design is in accordance with the joining method used, bolts or laser welding for example.

• Make sure that the prototypes are tested before mass production

• Communicate with your busbar manufacturer throughout the designing process

In most cases these practices are so efficient that they help to enhance thermal performance more than using thicker materials.

Common Mistakes Made by Buyers

A lot of buyers look only at the price, and this leads to a potential disaster down the road.

Examples of common mistakes include:

• Using regular busbars with custom batteries.

• Picking materials without regard for current needs.

• Overlooking tolerances.

• Choosing suppliers with little experience in battery pack manufacturing.

• Not submitting proper engineering drawings.

• Failing to take scalability into account.

A quality-designed busbar is a solid investment into battery endurance and reliability.

How to Choose the Right Supplier of Custom Busbars

Before you choose a supplier, consider these questions:

• Do they manufacture custom-made busbars?

• Are they capable of working from engineering drawings?

• Do they manufacture busbars from copper as well as aluminum?

• Can they perform laser welding?

• Which quality control methods do they apply?

• Are they experienced in manufacturing prismatic lithium batteries?

• Can they produce both prototypes and mass production?

What do you mean by a custom busbar for a prismatic lithium battery pack?

A custom busbar is defined as a dedicated copper/aluminum conductor that connects prismatic lithium cells and fits perfectly with the specific size, electrical values, and assembly requirements for a particular battery pack. The degree of customization helps achieve better infrastructure efficiency and reduced resistance.

Major Advantages of Custom Busbars

• Electrical resistance is reduced

• Heat generation is minimized

• Battery performance is enhanced

• Battery lifespan is extended

• Current distribution is improved

• It fits accurately

• Manufacturing represents fewer challenges

• Reliability increases significantly

Frequently Asked Questions

1. What causes busbars to heat up?

The heat produced by busbars is caused by electrical resistance. Bad design, wrong sizing, or wrong material choice can cause high resistance and result in higher temperatures.

2. Copper busbars or aluminum busbars which is better for battery packs?

Both copper and aluminum busbars have their own benefits in terms of performance. Copper busbars provide excellent electrical conductivity, while aluminum busbars save a lot on weight and can be successfully used in battery packs with laser welding technology. The selection is based on electrical and mechanical requirements of a specific application.

3. Do custom busbars prolong the battery life?

Yes, custom busbars help to make heat generation minimal and therefore stable operating temperatures of batteries, which leads to battery improvement.

4. Can custom busbars be laser welded?

Yes, aluminum busbars are manufactured with laser welding in mind and are well suited for this technology.

5. What information is needed to produce custom busbars?

Typically, manufacturers require engineering drawings, specifications of battery cells, the required current, preferred materials, dimensions, connections, and the required amount.

6. What industries use custom battery busbars?

Custom battery busbars are used in electric vehicles, energy storage systems, home inverters, telecom backups, industrial batteries, UPS systems, and robotics.

Final thoughts

Efficient thermal management does not start with the cooling system but rather with the internal electrical connections of the battery pack.

A custom copper busbar for prismatic cells lithium battery is expertly designed to minimize resistance, enhance current flow, and keep the operating temperature under control all these play a big role in improving the performance of batteries and their reliability in the long term.

Manufacturers of prismatic lithium battery packs can easily enhance their efficiency and durability by making sure they have a well-designed busbar that allows them to achieve better results.

Are you looking for a busbar for your battery pack?

If you create prismatic lithium battery packs, EV battery modules, or energy storage systems, working with a reputed custom busbar maker will help to streamline your design project and achieve great results. Adinath Enterprises manufactures drawing-based customized copper and aluminum busbars tailored to your exact battery pack requirements, helping ensure reliable electrical connections, precision fitment, and optimized thermal performance.