Cold Weather Lithium-Ion Battery Recharge Control

Solution Overview

Problem

Lithium-ion batteries used in Class I forklifts and auxiliary electric power supplies face capacity reduction and damage when recharged in cold temperatures, leading to reduced lifespan.

Innovation Solution

A lithium-ion battery module assembly with a recharge controller that heats the batteries before charging using resistive heating devices and a battery management system (BMS) to maintain optimal temperature, ensuring efficient charging and extending battery life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If lithium-ion batteries are recharged at freezing or near-freezing temperatures, then charging can proceed, but material damage occurs and capacity is reduced

Engineering Contradiction:

Improvecharging capabilityVSAvoidbattery capacity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary heating of the battery cells before charging begins. The controller monitors battery temperature and activates heating elements to raise the temperature above freezing point prior to initiating the charging process, preventing material damage while enabling charging capability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a recharge controller as an intermediary device between the power source and battery cells. This controller monitors temperature conditions and mediates the charging process by preventing charge current flow when temperatures are below freezing, thereby protecting battery capacity while maintaining charging capability when conditions are suitable.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If conventional charging methods are used in cold weather, then charging speed is maintained, but battery life is reduced due to degradation

Engineering Contradiction:

Improvecharging speedVSAvoidbattery lifespan

Core Design Contradiction:

SpeedVSDuration of action of stationary object

Solution Approach 1:

The system performs preliminary heating of the battery cells before charging begins. The controller monitors battery temperature and activates heating elements to raise the temperature above freezing point prior to initiating the charging process, preventing material damage while enabling charging capability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The recharge controller continuously monitors battery temperature and provides feedback control. When temperature drops below freezing, the controller activates heating elements and adjusts charging parameters accordingly, creating a closed-loop system that protects battery lifespan while maintaining optimal charging speed when conditions permit.

Inventive Principle:

Principle #23Feedback

3Device complexity

If battery temperature is not controlled during charging, then system complexity is reduced, but charging efficiency decreases and damage occurs

Engineering Contradiction:

Improvecontrol system complexityVSAvoidcharging efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent introduces a recharge controller as an intermediary device between the power source and battery cells. This controller monitors temperature conditions and mediates the charging process by preventing charge current flow when temperatures are below freezing, thereby protecting battery capacity while maintaining charging capability when conditions are suitable.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The battery system performs self-monitoring and self-protection through the recharge controller that automatically detects temperature conditions and adjusts charging parameters without external intervention. The system serves itself by preventing damage and optimizing charging efficiency based on real-time temperature feedback.

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution significantly extends the battery life by maintaining greater charge capacity and reducing degradation, allowing for longer operation times and increased cycle durability compared to conventional lead-acid batteries.

Implementation Method 1

a plurality of temperature sensors mounted on each collector plate for measuring the temperature of the lithium-ion battery cells

Methodology Applied

Scientific EffectTemperature sensing: Thermistor

Implementation Method 2

a plurality of resistive heating devices mounted on each collector plate in close proximity to each lithium-ion battery cell

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Data Source

PatentUS20220209320A1Life-extending recharge control for cold weather lithium-ion power supplies

Publication Date: 2022.06.30 ETHIUM LLC

AI summary

A lithium-ion battery assembly configured to provide electric power to a vehicle. The battery assembly includes a plurality of battery cells interconnected to provide a combined electrical potential between positive and negative terminals of the battery assembly, and a printed circuit board assembly (PCBA) disposed adjacent to a first array of battery cells of the plurality of battery cells. The PCBA includes a collector plate electrically coupled with the first array of battery cells, a temperature sensor configured to obtain temperature readings, a plurality of heaters configured to generate heat using electrical power, and an assembly processor. The assembly processor is configured to obtain readings from the temperature sensor, determine an estimated battery cell temperature, and initiate a heating program by delivering electrical power to the plurality of heaters from an electrical power source when the estimated battery cell temperature is below a threshold.