Battery Pack Voltage Sensing Paths for Accurate Charging Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery packs face challenges in accurately determining the battery voltage, leading to inefficient charging and potential degradation due to excessive charging currents or premature switching from CC to CV charging.
Innovation Solution
The battery pack incorporates a terminal unit with sensing terminals and resistors on voltage sensing paths, allowing for more accurate voltage sensing between battery terminals and pack terminals, thereby improving charging efficiency and pack longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If voltage sensing is performed between pack terminals, then charging control is simplified, but voltage measurement precision deteriorates due to voltage drops in current paths
Solution Approach 1:
The voltage sensing function is segmented into separate sensing paths that are electrically isolated from the high-current charging/discharging paths. Dedicated sensing terminals and low-current sensing wires are provided for each battery terminal, separating the measurement function from the power transmission function to eliminate voltage drop interference.
Solution Approach 2:
Dedicated sensing terminals and low-current sensing paths act as intermediaries between the battery terminals and the voltage detection circuitry. These intermediaries provide a separate measurement pathway that does not carry high charging/discharging currents, thereby accurately reflecting the battery terminal voltages without the influence of current-path voltage drops.
2Productivity
If charging current is increased to reduce charging time, then productivity improves, but battery degradation accelerates due to excessive current
Solution Approach 1:
The protective circuit continuously monitors the actual battery terminal voltages through the dedicated sensing paths and provides feedback control. Based on the real-time voltage feedback, the circuit dynamically adjusts the charging current to prevent excessive current that would cause degradation, while still maintaining high charging speeds when conditions permit.
Solution Approach 2:
The charging system transitions from static current control to dynamic current control based on real-time battery state. The protective circuit adjusts charging parameters dynamically according to the actual battery terminal voltages detected through the sensing paths, enabling optimal charging speed while preventing degradation.
3Device complexity
If voltage sensing paths share current paths, then device complexity is reduced, but measurement precision deteriorates due to voltage drops
Solution Approach 1:
The circuit is segmented into distinct current paths and voltage sensing paths. The voltage sensing paths are physically and electrically separated from the high-current charging/discharging paths, with dedicated sensing terminals and low-current sensing wires provided for each battery terminal. This segmentation eliminates the interference of current-path voltage drops on voltage measurements.
Solution Approach 2:
Dedicated sensing terminals and low-current sensing paths serve as intermediaries that provide a separate measurement pathway. These intermediaries connect the battery terminals to the voltage detection circuitry without carrying high charging/discharging currents, thereby accurately reflecting the battery terminal voltages without the influence of current-path voltage drops.
Data Source
AI summary
A battery pack includes a battery, a terminal unit, a first current path, a second current path, and a first voltage sensing path. The battery has first and second battery terminals. The terminal unit includes a first pack terminal, a second pack terminal, and a first sensing terminal. The first current path includes charging and discharging switches and is located between the first battery terminal and the first pack terminal. A charging current and discharging current of the battery flows on the first current path. The second current path is between the second battery terminal and the second pack terminal. The first voltage sensing path includes the first sensing terminal, and voltage between the first sensing terminal and another terminal corresponds to a voltage between the first battery terminal and the first sensing terminal.