Battery Pack Bus Bar Layout for Higher Current in Tight Space
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Solution Overview
Problem
Existing battery packs face challenges in ensuring a sufficient allowable current for the bus bar without increasing the size, particularly due to variations in materials used, which affect electrical conductivity.
Innovation Solution
The battery pack design includes a bus bar with fastening portions and wide portions that increase the cross-sectional area, allowing for enhanced electrical conductivity and space-saving by utilizing the space between adjacent electrical devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the bus bar material is changed or size is reduced, then the battery pack size is reduced, but the allowable current of the bus bar decreases
Solution Approach 1:
The bus bar features a wide portion with increased cross-sectional area located between fastening portions. This local quality change increases electrical conductivity and allowable current in the critical conduction path while maintaining overall compact dimensions for battery pack space saving
Solution Approach 2:
The bus bar cross-section transitions from a uniform shape to a non-uniform shape with a wide portion, effectively utilizing the space dimension between adjacent electrical devices to increase the cross-sectional area where current flows, thereby improving allowable current without increasing overall battery pack volume
2Reliability
If the bus bar cross-sectional area is increased, then the allowable current is improved, but the battery pack volume increases
Solution Approach 1:
Instead of uniformly increasing the entire bus bar cross-section, only a specific wide portion between fastening portions is enlarged. This localized approach improves allowable current where it matters most for electrical conduction while minimizing the impact on overall battery pack volume
Solution Approach 2:
The wide portion of the bus bar is positioned to utilize the available space between adjacent electrical devices in the vertical or lateral dimension, effectively using otherwise wasted space to increase the conductive cross-sectional area without expanding the battery pack's external dimensions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design ensures a sufficient allowable current for the bus bar regardless of material, achieves space savings, and improves heat dissipation while preventing erroneous assembly and reducing stress on fastening points.
Implementation Method 1
since a cross-sectional area of the bus bar is increased by the wide portion, electrical conductivity of the bus bar is increased, and a sufficient allowable current can be ensured for the bus bar
Implementation Method 2
improves heat dissipation while preventing erroneous assembly and reducing stress on fastening points
Data Source
AI summary
A battery pack includes: plural electrical devices at least one of which includes a cell stack in which plural battery cells are stacked; a bus bar which electrically connects the plural electrical devices; and a case which accommodates the plural electrical devices and the bus bar, the bus bar includes fastening portions provided at both ends of the bus bar and fastened respectively to terminals of the plural electrical devices, and a wide portion provided between the fastening portions and configured to have a width larger than a width of each of the fastening portions, and at least a part of the wide portion of the bus bar is disposed between adjacent ones of the plural electrical devices.