Flexible Aluminium Busbar & Aluminium Flexible Links

Carsai manufactures custom aluminium flexible busbar products for battery systems, transformers, busducts, switchgear, inverters and industrial power-distribution equipment.

Compared with copper, aluminium can reduce conductor weight and material cost in suitable applications. It is therefore increasingly considered for battery packs, energy storage systems, charging equipment and other high-current assemblies where total system weight matters.

We manufacture aluminium flexible conductors according to customer drawings, electrical requirements and installation conditions. Available designs include multilayer aluminium foil busbars, flat flexible conductors, formed terminals, flexible links and jumper connections.

Customers can specify the aluminium grade, conductor width, total thickness, number of layers, flexible-section length, terminal shape, mounting holes, surface treatment and insulation.

For an overview of copper, aluminium, braided and insulated structures, visit our Flexible Busbar Manufacturer page.

What Is an Aluminium Flexible Busbar?

An aluminium flexible busbar is a high-current conductor designed to carry electrical power while allowing limited movement between connected components.

Instead of using one thick rigid bar, the flexible section may be made from several thin aluminium sheets or foils stacked together. The individual layers can move slightly relative to one another, allowing the busbar to bend and absorb mechanical stress.

This structure can help compensate for:

• Thermal expansion and contraction
• Equipment vibration
• Assembly tolerances
• Small terminal misalignment
• Different mounting heights
• Movement between electrical components

The terminal areas are normally compressed, welded or formed into more rigid mounting sections, while the central part remains flexible.

Depending on the buyer and application, the same product may also be described as an aluminium flexible bar, flexible busbar aluminium, aluminium flex bar or multilayer aluminium connector.

Flexible Aluminium Flat Bar Construction

A flexible aluminum flat bar normally uses a flat, layered conductor structure rather than a round cable.

The flat design is useful inside compact equipment because it can provide:

• A low installation profile
• Large terminal contact surfaces
• Controlled bending direction
• Efficient use of cabinet space
• Direct connection to flat busbar terminals
• Reduced need for separate cable lugs

A typical product may contain multiple thin aluminium layers with solid or compressed terminal ends.

The design can be customized by changing:

• Individual layer thickness
• Number of aluminium layers
• Total conductor cross-section
• Flexible-section length
• Busbar width
• Terminal width
• Overall length
• Bend direction
• Hole pattern

Using more thin layers generally increases flexibility. Using fewer and thicker layers creates a stiffer conductor.

The correct structure should be determined according to the required current, mechanical movement, installation space and expected operating temperature.

Aluminium Flexible Busbar Versus Copper Flexible Busbar

Copper and aluminium can both be used for flexible busbars, but they have different properties.

Conductivity

Copper has higher electrical conductivity than aluminium. Therefore, an aluminium conductor normally requires a larger cross-sectional area to carry a similar current with a comparable temperature rise.

A copper design should not be replaced with aluminium using exactly the same dimensions without electrical evaluation.

Weight

Aluminium is considerably lighter than copper. This can be useful in:

• Electric vehicles
• Battery packs
• Mobile power systems
• Transport equipment
• Large busbar assemblies
• Equipment where structural weight is limited

Cost

Aluminium may offer a lower material cost, especially for larger conductor sections. However, the complete cost must also consider processing, terminal design, plating, welding and joint protection.

Installation space

Because aluminium usually needs a larger cross-section, it may require more installation space than copper.

Copper is often preferred where space is limited, while aluminium can be attractive where lower weight and material cost are more important.

Terminal reliability

Aluminium surfaces form an oxide layer naturally. This oxide layer can affect electrical contact if the joint is not designed and assembled correctly.

Aluminium busbar terminals require suitable preparation, surface treatment, joint pressure and fastening methods.

For projects connecting aluminium to copper, galvanic compatibility and transition design must also be considered.

Aluminium Flexible Link Applications

An aluminium flexible link connects two electrical components while allowing movement, vibration absorption or installation tolerance.

Common applications include:

Battery Modules and Energy Storage Systems

Aluminium flexible links may connect:

• Battery cells
• Battery modules
• Contactors
• Fuses
• Disconnect switches
• Power-distribution units
• Battery racks
• Energy storage cabinets

Aluminium is already widely used in some battery systems, making an aluminium flexible connection a practical option when the equipment has been designed around aluminium conductors.

The flexible section can reduce mechanical stress on battery terminals caused by vibration, thermal movement or installation deviation.

Transformers

Flexible links can be installed between transformer terminals and external busbars.

They help absorb vibration and compensate for small differences in terminal position. Depending on the current and equipment design, copper or aluminium may be selected.

Busduct and Busway Systems

Busduct systems experience thermal expansion as current and temperature change.

An aluminium flexible link can be installed at selected connection points to accommodate movement between busduct sections, transformers, switchboards or other equipment.

Switchgear and Distribution Equipment

Flexible aluminium conductors can connect breakers, switches, busbars and terminal assemblies inside power-distribution equipment.

They are particularly useful when a rigid busbar would require complicated bends or extremely precise installation alignment.

Inverters and Power Conversion Equipment

Inverters, PCS units and industrial converters may use aluminium flexible busbars between internal power modules and external terminals.

The conductor must be designed according to continuous current, peak current, switching conditions, available space and cooling.

Aluminium Flexible Jumper Connections

An aluminium flexible jumper is a short flexible conductor used to bridge two terminals or busbar sections.

Jumper designs can include:

• Straight flat connections
• Offset connections
• Bent terminals
• Different terminal widths
• Single-hole ends
• Two-hole or multi-hole terminals
• Slotted mounting holes
• Unequal terminal shapes
• Partially insulated structures

Flexible jumpers may be used when connected components cannot be joined reliably with a rigid bar.

They can also simplify assembly by allowing minor adjustment during installation.

For high-current applications, the terminal contact area must be large enough to prevent excessive local heating. The mounting holes, bolt size and fastening pressure should match the electrical load and equipment design.

Aluminium Grades and Material Selection

The aluminium alloy must be selected according to electrical conductivity, mechanical strength, forming performance and welding requirements.

Possible material selections may include commercially pure aluminium or electrical-grade aluminium alloys.

The final choice depends on:

• Required conductivity
• Busbar thickness
• Number of layers
• Terminal forming method
• Welding process
• Operating temperature
• Mechanical movement
• Surface-treatment requirement

Customers should specify the required aluminium grade on the drawing whenever possible.

When no material grade is defined, the application details should be reviewed before selecting a suitable material.

Surface Treatment and Joint Protection

Surface condition is especially important for aluminium electrical connections.

Available treatment options may include:

• Bare aluminium
• Tin-plated terminal areas
• Nickel plating for special applications
• Conductive joint compounds
• Protected contact surfaces
• Copper-aluminium transition sections

Tin plating can help improve contact compatibility and corrosion resistance in certain applications.

However, the plating process and base-material preparation must be suitable for aluminium.

For copper-to-aluminium connections, a direct unprotected joint may create galvanic corrosion under humid or contaminated conditions. A bimetallic transition section, appropriate plating or another controlled connection method may be required.

The complete joint design should consider:

• Mating material
• Humidity
• Salt or chemical exposure
• Operating temperature
• Bolt pressure
• Surface flatness
• Protective coating
• Maintenance requirements

Insulated Aluminium Flexible Busbars

Aluminium flexible busbars can be supplied bare or insulated.

Possible insulation options include:

• Heat-shrink tubing
• PVC sleeves
• Epoxy coating
• Powder coating
• Custom plastic insulation
• Partial insulation with exposed terminals

The correct insulation system depends on voltage, temperature, required flexibility and installation environment.

Insulation should cover conductive areas without preventing the flexible section from moving as intended.

The drawing should clearly define:

• Insulated areas
• Exposed terminal areas
• Insulation thickness
• Required color
• Voltage rating
• Temperature rating
• Edge coverage
• Terminal masking

Current Capacity and Conductor Sizing

An aluminium flexible busbar should not be sized only according to a general amperage chart.

Required conductor size depends on:

• Continuous current
• Peak current
• Short-circuit current
• Ambient temperature
• Cooling conditions
• Enclosed or open installation
• Duty cycle
• Allowable temperature rise
• Flexible-section length
• Terminal contact resistance
• Aluminium alloy

Two products carrying the same current may require different conductor sections when installed under different conditions.

Terminal heating must also be considered. Even if the flexible section has sufficient aluminium cross-section, small terminals or poor contact surfaces can create excessive resistance.

For an accurate design or quotation, customers should provide the current, voltage, installation environment and available space.

Custom Terminal and Dimensional Options

Carsai manufactures flexible aluminium busbars according to drawings rather than limiting customers to catalogue sizes.

Custom options include:

• Straight or bent terminals
• Offset mounting ends
• Different widths on both sides
• Customized layer quantity
• Round or slotted holes
• Single- or multi-hole terminals
• Tin-plated contact areas
• Partial or full insulation
• Prototype and batch production

Dimensional inspection can cover:

• Overall length
• Flexible-section length
• Busbar width
• Total conductor thickness
• Hole diameter
• Hole spacing
• Terminal flatness
• Bend angle
• Plating area
• Insulation position

Information Required for a Quotation

To receive a quotation, please provide:

• 2D or 3D drawing
• Aluminium grade
• Conductor width and thickness
• Number of layers
• Flexible-section length
• Overall dimensions
• Terminal dimensions
• Hole diameter and spacing
• Required bends or offsets
• Continuous current
• Peak current, when applicable
• Operating voltage
• Plating requirement
• Insulation requirement
• Order quantity
• Annual demand

A sample, sketch or installation photo can also be reviewed when the final drawing is not yet available.

Frequently Asked Questions

Can aluminium flexible busbars replace copper busbars?

Yes, in suitable designs. However, aluminium normally needs a larger cross-section than copper. Terminal compatibility, installation space and joint protection must also be reviewed.

Can you manufacture multilayer aluminium flexible busbars?

Yes. The layer thickness, number of layers, width and flexible length can be customized according to the drawing.

Can aluminium terminals be tin plated?

Tin-plated terminal areas can be evaluated according to the aluminium grade, application and project specification.

Can the two ends have different shapes?

Yes. Each terminal can have a different width, bend, hole pattern or offset.

Can aluminium flexible bars be insulated?

Yes. Heat-shrink, PVC, epoxy, powder coating and other insulation options can be considered.

Do you manufacture prototypes?

Prototype and small-batch production can be evaluated before regular-volume manufacturing.

Request an Aluminium Flexible Busbar Quotation

Carsai manufactures aluminium flexible busbars, flat flexible conductors, aluminium links and jumper connections for batteries, transformers, busducts, switchgear and power-conversion equipment.

Send us your drawing with the required current, aluminium grade, dimensions, terminal design, surface treatment, insulation and quantity.