Battery Module Self-Heating via Resistive Discharge

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Solution Overview

Problem

Electric vehicle batteries experience reduced electrical power output at low internal temperatures, necessitating an effective heating system to maintain optimal performance.

Innovation Solution

A heating system for battery modules that includes resistors and switches to generate heat energy and a temperature sensor to control fan operation, ensuring the battery temperature reaches a threshold level by partially discharging battery cell groups through resistors when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the battery operates at low internal temperatures, then the battery can function in cold environments, but the electrical power output is reduced below desired levels

Engineering Contradiction:

Improvebattery internal temperatureVSAvoidelectrical power output

Core Design Contradiction:

TemperatureVSPower

Solution Approach 1:

The patent converts the harmful effect of cold temperatures on battery performance into a beneficial heating mechanism. When the battery temperature is below the threshold, the control system activates resistors that utilize the battery's own electrical energy to generate heat through resistive heating (Joule heating). This self-heating process raises the battery temperature to optimal levels, thereby restoring electrical power output without external heating equipment.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The battery system performs self-heating using its own electrical energy. The control system monitors battery temperature and, when cold, directs electrical current through resistors integrated within the battery module. The resistors convert electrical energy to thermal energy, heating the battery from within. This self-service approach eliminates the need for separate external heating systems and maintains battery performance in cold environments.

Inventive Principle:

Principle #25Self-service

2Temperature

If resistors are used to generate heat energy by discharging battery cell groups, then the battery module temperature increases, but the battery capacity is partially discharged

Engineering Contradiction:

Improvebattery module temperatureVSAvoidbattery capacity

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent applies partial discharging of battery cell groups through resistors only when necessary to raise temperature above a threshold level. The control system monitors temperature continuously and activates the heating function only when the temperature falls below the threshold. Once the threshold is reached, the partial discharge stops. This partial action approach minimizes capacity loss while ensuring adequate heating only when required.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system changes the operational parameters of the battery by switching between normal discharge mode and heating mode. In heating mode, the control system alters the electrical circuit configuration to route current through resistors, changing the resistance parameter and thereby converting electrical energy to thermal energy. This parameter change enables temperature control while managing energy consumption through controlled partial discharge.

Inventive Principle:

Principle #35Parameter changes

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

Effectively increases the battery module temperature to a level that enhances electrical power output, addressing the power reduction issue at cold temperatures.

Implementation Method 1

at least partially discharge the first and second battery cell groups, respectively, through the first and second resistors, respectively, to generate heat energy in the first and second resistors

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

generate a third control signal to turn on a fan to distribute the heat energy in the battery module to increase the temperature level of the battery module

Methodology Applied

Scientific EffectForced convection: Forced Convection

Data Source

PatentUS8859119B2Heating system for a battery module and method of heating the battery module

Publication Date: 2014.10.14 LG ENERGY SOLUTION LTD

AI summary

A heating system and a method for heating a battery module are provided. The method includes generating a temperature signal indicative of a temperature level of at least one of a first battery cell group and a second battery cell group. If a temperature level is less than the threshold temperature level, then the method further includes generating first and second control signals to induce first and second switches, respectively, to each have a first operational position to at least partially discharge the first and second battery cell groups, respectively, through first and second resistors, respectively, to generate heat energy in the first and second resistors.