Battery Pack FCC Update Control via Voltage Descent Monitoring
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Solution Overview
Problem
Existing battery packs face challenges in accurately updating the full-charge capacity (FCC) of batteries due to degradation over repeated charge and discharge cycles, leading to inaccurate determination of battery lifespan.
Innovation Solution
A battery pack system that includes a monitoring unit for voltage, temperature, and current, a control unit that updates the FCC based on predetermined conditions, and a recording unit for storing the current FCC, ensuring accurate updates only during specific voltage descent conditions, thereby preventing inaccurate updates during voltage rise or discharging current reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the FCC is updated continuously during charge and discharge cycles, then the battery lifespan determination becomes more frequent, but the accuracy of FCC measurement deteriorates due to voltage fluctuations and current changes
Solution Approach 1:
The system performs preliminary actions by storing voltage, current, and temperature data during charge and discharge cycles before the actual FCC calculation. This preliminary data collection allows the system to later identify appropriate calculation时机 (when discharging current decreases or discharging is terminated) and perform accurate FCC measurements based on pre-collected reliable data, rather than attempting continuous updates during unstable voltage fluctuations.
Solution Approach 2:
The system implements feedback mechanisms by continuously monitoring voltage, current, and temperature parameters and using this information to determine when conditions are appropriate for FCC updates. The monitoring unit provides feedback about the battery state, and the control unit uses this feedback to decide whether to perform FCC calculations only when conditions indicate stable and accurate measurement opportunities, thereby maintaining both measurement precision and reliability.
2Productivity
If the FCC is updated during voltage rise sections, then the updating frequency increases, but the measurement accuracy decreases due to unstable voltage conditions
Solution Approach 1:
The system applies local quality by treating different voltage sections (rising vs. falling/stable) differently. Instead of uniformly updating FCC throughout the entire charge-discharge cycle, the system selectively updates FCC only in local sections where voltage conditions are stable (when discharging current decreases or discharging terminates). This localized approach ensures high measurement precision in specific favorable conditions while maintaining overall system productivity.
3Reliability
If multiple parameters (voltage, current, temperature) are monitored simultaneously, then the reliability of FCC determination improves, but the device complexity increases
Solution Approach 1:
The monitoring unit is designed with multi-functionality, serving multiple purposes: it monitors voltage for basic battery management, monitors current to determine appropriate FCC update timing, and monitors temperature for safety and accuracy corrections. By making the monitoring unit universal and multi-functional, the system achieves high FCC determination reliability through multi-parameter monitoring without proportionally increasing device complexity, as a single integrated monitoring unit performs all functions.
Data Source
AI summary
A battery pack and a method of controlling the battery pack are disclosed. In one embodiment, the battery pack includes a battery, a monitoring unit configured to monitor a voltage of the battery and provide a monitoring result, a memory storing a full-charge capacity (FCC) of the battery, and a controller configured to update the stored FCC when the monitoring result satisfies predetermined conditions during a falling period of the voltage.