Dynamic Battery Pack Cut-Off Voltage Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Rechargeable batteries in electric and hybrid vehicles face challenges in extending their lifespan due to excessive charging levels, which can lead to reduced capacity over cycles, necessitating a system to optimize battery pack recharging based on expected use.

Innovation Solution

A method and apparatus for controlling the charging system of electric vehicles by calculating travel miles, electrical energy requirements, and setting battery pack charging conditions based on user input, current state of charge, safety margins, road and traffic conditions, and weather, using a user interface and communication links to external data sources for optimized battery charging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the battery pack is charged to full capacity (100% state of charge), then the driving range is maximized, but the battery life is reduced due to excessive high voltage exposure

Engineering Contradiction:
Improvedriving rangeVSAvoidbattery life
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the charge cut-off voltage variable rather than fixed. The system dynamically adjusts the charge cut-off voltage based on real-time temperature measurements and battery state of charge, transitioning from a static charging protocol to an adaptive one that optimizes both battery life and driving range under varying conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameters during charging by implementing a multi-stage charging protocol where the charge cut-off voltage is adjusted based on temperature and state of charge. The system modifies charging parameters (voltage, current, cut-off points) dynamically to prevent excessive high voltage exposure while ensuring adequate charging capacity

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a fixed charge cut-off voltage is used, then the charging system is simple to implement, but it cannot optimize battery life under varying temperature and usage conditions

Engineering Contradiction:
Improvecharging system complexityVSAvoidbattery life
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements feedback control by continuously monitoring battery temperature and state of charge, then using this information to adjust the charge cut-off voltage in real-time. The system incorporates sensor feedback loops that feed temperature and voltage data back to the charge controller, which then modifies charging parameters accordingly

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically modifying its own charging parameters based on internal sensor data without requiring external intervention. The charge controller autonomously determines optimal cut-off voltages based on real-time battery conditions, enabling the system to self-optimize battery life extension

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2216199B1System for optimizing battery pack cut-off voltage
Publication Date: 2021.02.03 TESLA INC
  • EP2216199B1 patent drawingFigure 1~2
  • EP2216199B1 patent drawingFigure 3~4
  • EP2216199B1 patent drawingFigure 5~6

AI summary

A method and apparatus that allows the end user to control the charging system, and in particular the battery pack charging level, of an all-electric or hybrid vehicle based on expected use is provided.