Dynamic Discharge Detects Derated Battery Cells
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Solution Overview
Problem
Existing information handling systems face inefficiencies in battery management, particularly in the smart battery learn cycle, where discharge ends before reaching Under Voltage Protection mode, leading to lengthy calibration and degraded performance.
Innovation Solution
A dynamic discharging system that calculates and monitors accumulated discharge capacity and internal discharge time using A/D converters to identify derated battery cells by assigning one value as fixed and using the other to determine cell health, allowing for partial capacity discharge while maintaining accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the battery is completely discharged to calibrate the coulomb counter, then the calibration accuracy is improved, but the discharge time increases significantly and user performance is degraded
Solution Approach 1:
The patent applies partial action by performing a learn cycle that discharges only a portion of the battery capacity (e.g., from 100% to 50% or 75%) rather than completing a full discharge to Under Voltage Protection. This partial discharge is sufficient to detect derated cells and calibrate the coulomb counter with acceptable accuracy, while dramatically reducing the time penalty and performance degradation associated with complete discharges.
Solution Approach 2:
The system changes the discharge parameters by using dynamic discharge current adjustment and monitoring voltage thresholds differently during the learn cycle. Instead of discharging to a fixed low voltage endpoint, the system adapts the discharge process based on real-time measurements of discharge capacity and time, allowing early termination when sufficient calibration data is obtained, thus reducing overall discharge time while maintaining accuracy.
2Loss of time
If the discharge ends before reaching Under Voltage Protection mode, then the discharge time is reduced, but the calibration accuracy may be compromised
Solution Approach 1:
The patent implements feedback mechanisms by continuously monitoring discharge capacity, discharge time, and voltage during the learn cycle. The system uses this real-time data to determine when sufficient calibration information has been collected, allowing the discharge to terminate early without compromising accuracy. The feedback loop compares measured values against expected ranges to verify calibration quality before ending the cycle.
Solution Approach 2:
The system performs preliminary measurements and calculations during the discharge process to predict whether full calibration accuracy will be achieved. By monitoring discharge characteristics in real-time and comparing them against known good battery profiles, the system can determine in advance whether the partial discharge will be sufficient, avoiding unnecessary extended discharge time while ensuring adequate calibration.
3Reliability
If traditional learn cycle methods are used, then calibration is performed, but derated battery cells cannot be detected and accuracy is reduced
Solution Approach 1:
The patent applies dynamics by transitioning from static, fixed-protocol learn cycles to a dynamic learn cycle that adapts in real-time. The system continuously adjusts discharge current, monitors voltage slopes, and modifies the discharge endpoint based on observed battery behavior. This dynamic approach enables the detection of derated cells because the system responds to actual battery characteristics rather than following a rigid predetermined sequence, improving both reliability and measurement precision.
Solution Approach 2:
The learn cycle is segmented into multiple phases with different monitoring and measurement objectives. Rather than a single uniform discharge process, the patent divides the calibration into stages: initial discharge with one set of parameters, mid-discharge assessment points to detect derated cells, and final calibration phases. This segmentation allows the system to identify problematic cells early and adjust subsequent measurements, improving overall detection accuracy without requiring excessive discharge time.
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 approach improves the accuracy of detecting faulty cells, reduces error from self-discharge and circuit leakage, and shortens discharge time by 10-20 minutes, enhancing overall battery management efficiency.
Implementation Method 1
an accumulated discharge capacity value is calculated and monitored by a charge level battery gas gauge via analog to digital (A/D) converters and an internal discharge time value is monitored
Data Source
AI summary
A system for dynamic discharging to detected derated battery cells. In such a system, a battery cell capacity, cell voltage, as well as a time to discharge are used in combination to identify good or bad battery cells. More specifically, during a dynamic discharge cycle, an accumulated discharge capacity value is calculated and monitored by a charge level battery gas gauge via analog to digital (A/D) converters and an internal discharge time value is monitored. One of the values is assigned as a fixed value and the other value is used to identify good or bad batter cells.