Battery Pack Charging Control with Sleep-Wake BMS Relay Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery packs suffer from self-discharge due to the continuous power-on state of the battery management system (BMS), leading to unnecessary discharge and degraded charging efficiency, and measurement errors occur due to cable connections between the battery pack and charger.
Innovation Solution
A battery pack design that includes a BMS, relay, and fuse, where the BMS is only activated when needed, minimizing self-discharge and enabling efficient charging by controlling the relay and fuse operations based on battery detection information, and using a controller and charger to manage power distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery management system (BMS) is always powered on to enable voltage measurement and charging control, then charging functionality is maintained, but self-discharge occurs continuously causing unnecessary energy loss
Solution Approach 1:
The BMS is activated periodically only when charging is required rather than continuously. The system transitions between active and sleep states, with the controller turning on the BMS when voltage measurement or charging control is needed, and turning it off when not needed, thereby eliminating continuous self-discharge while maintaining charging functionality.
2Speed
If the BMS is always powered on to ensure immediate response to charging requests, then charging readiness is improved, but unnecessary power consumption increases
Solution Approach 1:
The system performs preliminary voltage measurement and state assessment before activating the BMS for full charging operation. The controller checks basic battery status first, and only activates the BMS when actual charging is needed, thus preparing the system in advance while avoiding unnecessary continuous power consumption.
3Measurement precision
If voltage measurement is performed continuously to monitor battery state, then battery management accuracy is improved, but charging efficiency is degraded due to cable-induced measurement errors
Solution Approach 1:
The system uses an intermediary measurement approach where the controller measures voltage through the cable connection during actual charging operations rather than continuous measurement. This eliminates cable-induced measurement errors that occur during idle states, as the cable is only connected when charging is actively occurring, thus maintaining measurement accuracy while improving charging efficiency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a battery pack, including: at least one battery module which includes a plurality of battery cells and is connected between a first terminal and a second terminal; a relay connected between the first terminal and a third terminal; and a battery management system (BMS) which is connected to the first to third terminals, and generates a charge control signal controlling a charge operation of a charger connected to the third terminal based on battery detection information obtained by detecting the plurality of battery cells and the at least one battery module.