Double-Chamber Battery Venting for Uniform Cell Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Valve regulated lead acid batteries experience uneven drying-out due to varying check valve trigger thresholds, leading to electrolyte and gas leakage, posing safety hazards and reducing battery life expectancy.
Innovation Solution
A battery venting system with a two-chamber design, where a calibrated one-way valve is positioned inside the battery case, preventing external contamination and equalizing pressure between cells, and an electronic control device with a pressure sensor manages charging to prevent excessive pressure buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If check valves are used to prevent gas exchange between cells, then cell isolation is improved, but uneven drying-out occurs due to varying trigger thresholds
Solution Approach 1:
A gas collection chamber is introduced as an intermediary component between the battery cells and the external environment. All check valves discharge into this common chamber, which equalizes pressure across all cells before any gas escapes externally. This mediator ensures uniform drying-out while maintaining cell isolation, resolving the contradiction between reliable cell separation and stable electrolyte composition.
2Stress or pressure
If check valves open at varying pressure thresholds, then pressure relief is achieved, but uneven gas discharge causes premature battery aging
Solution Approach 1:
The gas collection chamber creates an equipotential pressure environment by collecting gases from all cells at different pressure levels and equalizing them before external discharge. This ensures that cells with higher gassing rates do not lose excessive gas, as the common chamber buffers the pressure differences. Consequently, all cells age uniformly, extending overall battery life while maintaining effective pressure relief.
3Stability of the object's composition
If a gas collecting chamber is used to equalize pressure, then uniform drying-out is achieved, but electrolyte leakage poses safety hazards
Solution Approach 1:
The harmful electrolyte leakage is extracted and isolated from the main battery system by directing it into a separate gas collection chamber. The chamber's design contains the leaked electrolyte within the battery housing, preventing external contamination while maintaining uniform pressure equalization. This extraction approach preserves the benefit of uniform drying-out while eliminating the safety hazard of external electrolyte leakage.
4Reliability
If check valves are retained to prevent oxygen cross-contamination, then electrode protection is improved, but gas leakage through faulty seals increases explosion risk
Solution Approach 1:
Multiple check valves that individually pose leakage risks are merged into a unified gas collection chamber system. Even if individual valve seals fail, the common chamber contains the leaked gases and electrolytes within the battery housing, preventing external explosion hazards. The merged system maintains electrode protection while reducing the overall explosion risk associated with individual valve failures.
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
The system minimizes external contamination and reduces the risk of explosions by containing gases and electrolytes within the battery, ensuring uniform cell pressure and extending battery life.
Implementation Method 1
The check valves are configured as one-way valves that allow fluid to flow only from the inside to the outside of a cell. The check valves usually open when the pressure difference between the inside and the outside of a cell reaches a trigger threshold.
Implementation Method 2
The calibrated one-way valve is positioned in the separating wall for providing a fluid communication between the first volume and the second volume when open, and for sealing the first volume from the second volume when closed.
Implementation Method 3
The first chamber is continuously bonded to the case of the battery such that the first volume is hermetically sealed, when the check valves and the calibrated one-way valve are closed.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A battery venting system for batteries such as VLRA (valve regulated lead acid batteries) is provided that comprises at least one check valve (16) for each cell (12) of the battery (10), a first chamber (21, 13) enclosing a first volume (14), a calibrated one-way valve (24), and a second chamber (23, 21') enclosing a second volume (50), the second volume (50) being separated from the first volume (14) by a separating wall (21') common to the first and second chambers. Each check valve (16) is provided between its respective battery cell (12) and the first volume (14) to enable a fluid communication between the respective cell and the first volume when open and to seal the respective battery cell (12) when closed. The calibrated one-way valve (24) is positioned in the separating wall (21') for providing a fluid communication between the first volume (14) and the second volume (50) when open, and for sealing the first volume (14) from the second volume (50) when closed. The first chamber (21, 13, 40, 42) is continuously bonded to the case (11) of the battery (10) such that the first volume is hermetically sealed, when the check valves (16) and the calibrated one-way valve (24) are closed. The second chamber (23, 21') has an outlet opening (27) providing the only fluid communication from the second volume (50) to the surrounding of the battery venting system (20) and the battery (10), with the second chamber being continuously bonded to the first chamber for providing, with the exception of the outlet opening (27), a hermetically sealed encasing for the second volume and from the complete battery. The battery venting system (20) is configured such that when the second chamber (23, 21') is in normal use located above the first chamber (21, 13), the inlet port of the calibrated one-way valve (24) is located above the bottom of the first chamber (21, 13), and when the second chamber (23, 21') is in normal use located below the separating wall (21'), the inlet port of the calibrated one-way valve (24) is located above the surface of the separating wall (21') facing to the first volume (14).