Battery Charging Control Using Dummy Cell Voltage Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rechargeable battery charging control systems inaccurately determine full charge due to laminated layer degradation, leading to premature termination of charging and reduced energy capacity.
Innovation Solution
A control device utilizing a rechargeable dummy cell to measure open circuit voltage and determine the maximum capacity increment of the battery, allowing for precise charging control by integrating the charging current over time and considering degradation, thereby avoiding overcharging and ensuring full charge is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If battery voltage monitoring is used to control charging, then charging control is simple, but charging terminates prematurely due to degradation-induced voltage increase
Solution Approach 1:
A dummy cell is introduced as an intermediary component that replicates the electrical characteristics of the actual battery. The dummy cell serves as a mediator between the charging control system and the battery, allowing voltage monitoring without directly measuring the degraded battery's voltage. This resolves the contradiction by providing accurate full-charge detection through the dummy cell's stable voltage characteristics while keeping the control system relatively simple.
Solution Approach 2:
The patent creates a copy of the battery in the form of a dummy cell that mimics the battery's electrical behavior. This copy is used for voltage monitoring purposes, eliminating the measurement errors caused by the actual battery's degradation. The copying principle allows the control system to base charging decisions on the dummy cell's accurate voltage readings rather than the degraded battery's misleading voltage signals.
2Reliability
If charging is stopped when voltage reaches upper limit, then overcharging is prevented, but energy capacity is reduced due to degradation
Solution Approach 1:
The dummy cell acts as an intermediary that provides accurate voltage information for determining when the battery is truly full. By monitoring the dummy cell's voltage rather than the degraded battery's voltage, the system can safely extend charging beyond the premature termination point while still preventing actual overcharging. This resolves the contradiction by maintaining reliability through the dummy cell's accurate signaling while maximizing energy capacity utilization.
Solution Approach 2:
The system uses feedback from the dummy cell's voltage measurements to dynamically adjust charging control decisions. The dummy cell provides continuous feedback about the battery's true charge state, allowing the control system to optimize the charging termination point. This feedback mechanism enables the system to prevent overcharging while capturing maximum available energy capacity, resolving the contradiction between safety and energy utilization.
3Measurement precision
If dummy cell is added for accurate capacity monitoring, then charging precision is improved, but device complexity increases
Solution Approach 1:
Instead of adding complex measurement instruments to monitor the actual battery, the patent uses a simplified copying approach with a dummy cell. The dummy cell is a straightforward electrical component that replicates battery behavior, providing accurate capacity increment measurements without requiring complex instrumentation. This resolves the contradiction by achieving high measurement precision through the elegant simplicity of the dummy cell copy rather than through complex measurement systems.
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 solution enables reliable and accurate charging control, preventing overcharging and ensuring the battery reaches 100% state of charge, thereby maintaining energy capacity and extending battery life.
Implementation Method 1
a second circuit configured to measure the open circuit voltage of the dummy cell
Data Source
AI summary
A control device for controlling charging of a rechargeable battery, the control device including a rechargeable dummy cell, a first circuit configured to charge the battery and the dummy cell, and a second circuit configured to measure the open circuit voltage of the dummy cell. The control device is configured to: determine the open circuit voltage of the dummy cell by using the second circuit, and determine the maximum capacity increment of the battery, which is to be charged until full charging, based on the determined open circuit voltage of the dummy cell. Also, a corresponding method of controlling charging of a rechargeable battery.