Battery Management Circuit for Adaptive Charging Control
Solution Overview
Problem
Existing battery management systems face challenges in maintaining uninterrupted power supply to loads during power failures and efficiently managing battery health and charge, particularly in systems with multiple batteries, where coordination and balancing are complex.
Innovation Solution
A battery management circuit with a MOSFET switch and current sensing circuit that isolates batteries from the power supply to evaluate open circuit behavior while maintaining current flow to loads, and includes a battery measurement circuit to determine state of charge and health, ensuring efficient power distribution and balancing across multiple batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a MOSFET switch is used to isolate batteries from power supply for evaluation, then battery open circuit behavior can be evaluated, but current flow to load must be maintained during power failure
Solution Approach 1:
The patent employs diodes as intermediary components in the switching circuit to enable automatic current redirection. When the power supply fails, the diodes naturally conduct current from the battery to the load without requiring complex active switching control, thus maintaining uninterrupted power supply while allowing battery evaluation during normal operation.
Solution Approach 2:
The switching circuit dynamically changes its configuration based on power supply status. During normal operation, the MOSFET isolates the battery for accurate open circuit evaluation. Upon power failure detection, the circuit automatically transitions to conduct current from battery to load, achieving both measurement precision and reliability through dynamic adaptation.
2Quantity of substance
If multiple batteries are managed in a battery pack, then power capacity is increased, but coordination and balancing complexity increases
Solution Approach 1:
The battery pack is segmented into multiple independent battery units, each with its own management circuitry. This segmentation allows individual monitoring and control of each battery, simplifying the coordination and balancing of multiple batteries while maintaining increased power capacity through parallel configuration.
Solution Approach 2:
The battery management circuit is designed with multi-functional capabilities to handle charging, discharging, balancing, and protection functions for multiple batteries through a unified control architecture. This universal design reduces overall system complexity despite managing multiple battery units.
3Measurement precision
If battery isolation is implemented for open circuit evaluation, then measurement accuracy is improved, but power supply continuity to load is compromised
Solution Approach 1:
The system implements periodic switching between measurement mode and power supply mode. During normal operation, batteries are periodically isolated for open circuit voltage measurement to assess state of charge and health. When power failure is detected, the system continuously maintains power flow from battery to load, achieving both measurement accuracy and power continuity through time-based control.
Data Source
AI summary
A battery management circuit and method for managing a power supply and one or more battery strings includes a current sensing circuit and a battery measurement circuit. The current sensing circuit is configured to: receive a current signal from at least one of the battery strings at a first terminal of the current sensing circuit; measure a magnitude of the current signal; and provide a current sensing signal indicative of the magnitude of the current signal at a third terminal of the current sensing circuit. The battery measurement circuit is configured to: receive a current sensing signal at a third terminal of the battery management circuit; measure one or more characteristics of the at least one of the battery strings; and provide a power supply control signal at a first terminal of the battery measurement circuit.