Parallel Battery Cell Management via Switch Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-cell rechargeable battery packs face challenges due to non-uniformity among cells, leading to reduced capacity and shortened lifespan, as well as the risk of the entire pack failing if one cell is damaged, due to manufacturing tolerances and mismatched cell degradation during charge/discharge cycles.
Innovation Solution
A system with switches and a controller that connects and disconnects battery cells or series stacks based on their state, allowing cells with higher capacity to undergo more charge/discharge cycles, thereby extending the overall battery life by managing the charge/discharge processes selectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple battery cells are connected in parallel to increase capacity, then the battery capacity increases, but the non-uniformity among cells leads to reduced overall capacity and shortened lifespan
Solution Approach 1:
The battery management system segments the parallel-connected cells into individually controllable groups using switches. Each cell or series stack can be independently connected or disconnected from the parallel configuration, allowing the system to manage cells with different states of health separately while maintaining overall battery operation.
Solution Approach 2:
The system dynamically reconfigures the battery architecture by selectively actuating switches based on real-time cell state assessment. The controller continuously monitors cell characteristics and adjusts the parallel connections accordingly, transitioning from a static parallel configuration to a dynamic, adaptive configuration that optimizes for both capacity and reliability.
2Productivity
If all cells are connected in parallel to maximize capacity utilization, then the battery delivers maximum current, but a single degraded cell can cause entire pack failure
Solution Approach 1:
The system extracts problematic cells or series stacks from the parallel configuration by actuating their corresponding switches to disconnect them. This allows the remaining healthy cells to continue delivering current while isolated degraded cells are removed from the active configuration, preventing them from causing pack failure.
Solution Approach 2:
The system applies different operational states to different cells based on their individual characteristics. Healthy cells remain connected and active, while degraded cells are disconnected or placed in different operational modes. This local differentiation allows the battery pack to maintain high current delivery capability from functional cells while protecting against failure from degraded cells.
3Stability of the object's composition
If cells are tied together in parallel to undergo the same charge/discharge cycles, then the battery operates as a unified pack, but mismatch between cells increases after multiple cycles reducing the benefit of binning
Solution Approach 1:
The controller continuously monitors the state of each cell or series stack by measuring characteristics such as voltage, current, and temperature. This feedback information is used to determine when to actuate switches to reconfigure the parallel connections, allowing the system to compensate for capacity mismatch that develops over time and maintain optimal operation despite manufacturing variations.
Data Source
AI summary
The present system and method manage a rechargeable battery comprising two or more battery cells or series stacks of cells. The system includes a set of switches, each of which connects a cell or stack of cells between positive and negative nodes when actuated, or connects one cell in a stack of cells to another cell in the stack when actuated, such that when all the switches in a given stack are actuated, it is connected between the positive and negative nodes. An electrical load is directly connected to the positive and negative nodes. A controller determines the state of each cell or stack of cells by measuring and/or calculating one or more predetermined characteristics, and selectively actuates the switches based on the states of the cells or stacks of cells so as to enhance the life of the battery.