EV Battery Architecture Without a Negative Contactor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicle battery architectures with main positive and negative contact switches are heavy, consume space, experience high contact resistance leading to increased temperatures and higher costs.
Innovation Solution
A battery architecture that omits the negative contactor and includes a positive contactor along with first and second fuses (pyrofuses) connected between battery cells and the negative terminal, allowing the battery management system to selectively open the positive contactor to dissipate power during detected events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both main positive and negative contact switches are included in the battery architecture, then the system provides complete control over power flow, but the weight and device complexity increase
Solution Approach 1:
The patent removes the main negative contactor from the battery architecture, extracting only the essential positive side control while maintaining safety through alternative means (negative terminal fuse and module-level fuses). This reduces weight and complexity while preserving the core function of controlling power flow from the battery pack.
2Reliability
If both main positive and negative contact switches are included in the battery architecture, then the system provides complete control over power flow, but the device complexity and cost increase
Solution Approach 1:
The patent eliminates the main negative contactor and its associated control circuitry, reducing device complexity. The control function is redistributed to simpler components: a positive contactor for main power control and fuses for protection, which require less complex control systems while maintaining safety and functionality.
3Reliability
If main contact switches are included in the battery architecture, then the system can control power flow, but contact resistance increases leading to higher temperatures
Solution Approach 1:
By removing the main negative contactor, the patent eliminates a source of contact resistance and heat generation. The negative terminal connection remains permanent with direct metal-to-metal contact, avoiding the thermal issues associated with high-current contact switches while preserving the ability to control power flow through the positive contactor.
Data Source
AI summary
Systems and methods for a battery architecture include a first fuse connected between a first battery cell and a second battery cell of a battery pack, and a second fuse connected between the second battery cell and a terminal of a charge port.