How to Choose the Right Battery Busbar? A Comprehensive Guide to Materials, Dimensions, and Current-Carrying Capacity
Introduction
Choosing the right battery busbar is essential for ensuring safety, thermal stability, and electrical performance in EVs, drones, and energy storage systems. In this guide, we’ll break down the core selection criteria — including materials, geometry, ampacity, and plating — with expert input from Wellgo Battery, a leading supplier of custom battery interconnect solutions.
Understand Your System’s Requirements
The first step to selecting the correct custom busbar is understanding the system’s electrical and environmental conditions.
● What’s the voltage and current range?
● Is the application mobile (e.g. e-bike) or stationary (e.g. ESS)?
● Will the busbar be exposed to heat, moisture, or vibration?
For instance, Wellgo’s nickel-plated copper busbars are designed for high-current EV packs with strong anti-corrosion performance.
Check out Wellgo’s custom battery busbars
Choose the Right Material: Copper vs. Aluminum
Copper busbars offer excellent conductivity (up to 59.6 MS/m) and mechanical durability, making them the top choice for most lithium battery packs. Aluminum busbars are lighter and more cost-effective, but less conductive.
🔗 According to IEEE 837-2014, copper is preferred in high-reliability systems due to better long-term performance and lower thermal resistance.
Calculate the Required Ampacity
To avoid overheating and ensure safety, you must size the busbar cross-section correctly. The simplified formula:
Ampacity (A) = Current x Safety Factor / Conductivity Coefficient
Wellgo’s copper-nickel busbars can handle over 1000A per square inch while maintaining low voltage drop.
Match Geometry to Battery Layout
The shape and layering of a busbar directly affect resistance and cooling efficiency. Use CAD to design:
● Flat busbars for simple connections
● Laminated busbars for reduced EMI
● Grid-style connectors for dense battery packs
Wellgo offers design-to-delivery services including CAD matching and prototyping for optimal mechanical and electrical fit.
Consider Mounting and Safety Compliance
Busbars must align with your system’s mounting hardware and meet regional certifications:
● UL 94-V0 for flammability
● IEC 61439 for low-voltage switchgear
● RoHS/REACH for environmental compliance
Choose battery module busbars with pre-punched holes and protective insulation for safe, plug-and-play integration.
Final Tip: Go Custom for Best Results
Off-the-shelf doesn’t work for everyone. For specialized needs — like modular BMS upgrades or tight pack spaces — go for a custom battery busbar designed to fit your specs.
Wellgo supports full-stack customization, from CAD design and sampling to bulk manufacturing.
