Dual-Battery Power Switching for Low-Temperature Voltage Stability

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Solution Overview

Problem

Battery packs in terminal devices using multiple batteries in parallel mode face stability issues due to increased internal resistance at low temperatures, leading to reduced output voltage and potential device shutdown.

Innovation Solution

A power supply system that switches between series and parallel modes, controlled by a controller that determines the optimal mode based on output voltage, temperature, and load current, using a voltage step-down circuit and bypass circuit to maintain stable power supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If batteries are connected in parallel mode, then battery capacity is increased, but output voltage decreases and stability is reduced at low temperatures

Engineering Contradiction:
Improvebattery enduranceVSAvoiddevice stability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent implements dynamic switching between parallel and series connection modes based on temperature conditions. The controller automatically adjusts the battery connection configuration in response to temperature changes, transitioning from static parallel connection to dynamic adaptive connection. This resolves the contradiction by allowing the system to maintain high voltage in cold conditions (series mode) while preserving battery endurance capability (parallel mode) when conditions permit.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical connection parameter (series vs. parallel) based on temperature parameters. When temperature drops below a threshold, the system switches from parallel connection (higher capacity, lower voltage) to series connection (lower capacity, higher voltage). This parameter adaptation allows the system to maintain sufficient output voltage at low temperatures while preserving the option for extended endurance operation.

Inventive Principle:
Principle #35Parameter changes

2Power

If batteries are connected in series mode, then output voltage is improved, but battery discharge efficiency decreases

Engineering Contradiction:
Improveoutput voltageVSAvoiddischarge efficiency
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The system dynamically switches between series and parallel modes based on operational requirements. Series mode is activated temporarily when high voltage is needed (low temperature conditions), while parallel mode is used during normal operation for efficient energy discharge. This dynamic approach minimizes energy loss by limiting series mode usage to only when necessary for maintaining device operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The controller periodically monitors temperature and voltage conditions, switching between connection modes as needed. The system uses series connection periodically when temperature thresholds are breached, then returns to parallel mode for efficient discharge. This periodic switching strategy balances the need for high voltage with the goal of maintaining optimal discharge efficiency.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3993217B1Power supply system and method for a terminal device
Publication Date: 2023.10.04 HUAWEI TECH CO LTD
  • EP3993217B1 patent drawingFigure 1~2
  • EP3993217B1 patent drawingFigure 3~4
  • EP3993217B1 patent drawingFigure 5~6

AI summary

This application provides a power supply system and method for a terminal device, a chip, and a terminal device, and relates to the charging field. The power supply system includes a battery pack, a bypass circuit, a voltage step-down circuit, and a controller. The battery pack includes at least two batteries. An output end of the battery pack is connected to an input end of the voltage step-down circuit, an output end of the voltage step-down circuit is connected to a power consumption element of the terminal device, one end of the bypass circuit is connected to the input end of the voltage step-down circuit, and the other end of the bypass circuit is connected to the output end of the voltage step-down circuit. The controller is configured to: when the batteries in the battery pack need to be switched to a series mode, control the voltage step-down circuit to work and control the bypass circuit to stop working, and is further configured to: when the batteries in the battery pack need to be switched to a parallel mode, control the bypass circuit to work and control the voltage step-down circuit to stop working. In the system, switching between the series mode and the parallel mode can be automatically implemented based on an actual situation, so that endurance can be increased while stability of the terminal device is improved.